Environment Council of Central Queensland Inc v Minister for the Environment and Water

Federal Court of Australia (Full Court)|2024-05-16|Before: Mr J, Ms J, Australia J, Mortimer CJ, Horan JJ, Colvin J

BACKGROUND 3 The Narrabri appeal in VID 885 of 2023 concerns a proposed action to extend underground mining operations at the existing Narrabri underground mine in New South Wales, extending the life of the mine from 2031 to 2045 with a maximum output of up to 11 million tonnes per annum (Mtpa) of coal. The Mt Pleasant appeal in VID 886 of 2023 concerns a proposed action to increase the open cut coal extraction within the already approved Mount Pleasant project development area from 10.5 Mtpa to up to 21 Mtpa of coal, including accessing deeper coal reserves, continued use of the controlled release dam and extending the life of the mine from 2035 to 2048. The second respondents in the appeals are the respective proponents of each action. 4 In each case, a delegate of the Minister made a controlled action decision under s 75(1) of the EPBC Act that ss 18 and 18A (listed threatened species and communities); and ss 24D and 24E (protection of water resources from unconventional gas development and large coal mining development), were the controlling provisions. 5 Section 75(1) of the EPBC Act provides: Is the action a controlled action? (1) The Minister must decide: (a) whether the action that is the subject of a proposal referred to the Minister is a controlled action; and (b) which provisions of Part 3 (if any) are controlling provisions for the action. Note: The Minister may revoke a decision made under subsection (1) about an action and substitute a new decision. See section 78. 6 Neither of the controlled action decisions identified as "relevant impacts" (see s 82 of the EPBC Act) any impacts on matters of national environmental significance (MNES) (see Pt 3 Div 1 of the EPBC Act) arising from the greenhouse gas emissions (GHG emissions) associated with the extension of the operation of the coal mines. It is the contended existence of these impacts which prompted the appellant's two reconsideration requests under s 78A of the EPBC Act. 7 As the Minister expressed it in her statement of reasons about the Mt Pleasant project (at [13]): EJA requested that I revoke the original referral decision and substitute a new decision under section 75(1) of the EPBC Act, listing all MNES that it had identified as affected by climate change as controlling provisions. 8 Section 78A(1) of the EPBC Act provides: (1) A person (other than a Minister of a State or self-governing Territory) may request the Minister to reconsider a decision made under subsection 75(1) about an action on the basis of a matter referred to in any of paragraphs 78(1)(a) to (ca). Note: Section 79 deals with requests for reconsideration by a Minister of a State or self-governing Territory. 9 Section 78(1)(a) of the EPBC Act is the applicable part of s 78(1) for the purposes of these appeals. It provides: Limited power to vary or substitute decisions (1) The Minister may revoke a decision (the first decision) made under subsection 75(1) about an action and substitute a new decision under that subsection for the first decision, but only if: (a) the Minister is satisfied that the revocation and substitution is warranted by the availability of substantial new information about the impacts that the action: (i) has or will have; or (ii) is likely to have; on a matter protected by a provision of Part 3; or … 10 Section 78C(1) of the EPBC Act provides: Reconsideration of decision (1) As soon as practicable after the end of the time within which information or comments may be given under section 78B in relation to a request under section 78A to reconsider a decision about an action, the Minister must: (a) reconsider the decision; and (b) either: (i) confirm the decision; or (ii) revoke the decision in accordance with subsection 78(1), and substitute a new decision for it. 11 The appellant provided the Minister with what it contended was "substantial new information" (within the meaning of s 78(1)(a)) about the impacts, or likely impacts, of each proposed action on matters protected by Pt 3 of the EPBC Act. The appellant contended that the delegate had not considered the effects of GHG emissions from the combustion of coal produced by the two mines, if their life and production capacity were extended as the second respondents sought to do. In its letter to the Minister in support of its reconsideration requests, the appellant contended: The substantial new information enclosed with this request and summarised in the enclosed Annexures demonstrates that, by those emissions, the Proposed Project will, or is likely to, have significant physical effects on a number of matters of national environment significance (MNES), including a number not listed as controlling provisions in the controlled action decision. In essence, there is now a global scientific consensus that widespread and catastrophic harm to people, ecosystems, species and the biosphere as a whole is in train as a result of the greenhouse gas emissions created by burning fossil fuels. (Original emphasis.) 12 In each reconsideration request, the appellant requested that the Minister revoke the original controlled action decisions and substitute a new decision under s 75(1) of the EPBC Act, listing all MNES that it had identified as affected by climate change as controlling provisions. 13 The Minister decided not to revoke the controlled action decisions and instead confirmed them pursuant to s 78C(1)(b)(i) of the EPBC Act.

THE CORRECT UNDERSTANDING OF THE MINISTER'S REASONS 14 The judicial review before the primary judge was conducted by reference to the Minister's statement of reasons in relation to the Mt Pleasant proposal. It was accepted before the primary judge "that there is no material difference between it and the Narrabri proposal" (see primary judgment [16]). The same approach was taken on appeal. Therefore, where we use the term the Minister's reasons, we refer to the Minister's statement of reasons dated 11 May 2023 in respect of the s 78A reconsideration request for the Mt Pleasant proposal. Likewise, where we discuss the grounds of appeal, we do principally by reference to the Mt Pleasant further amended notice of appeal and the parties' submissions. Our reasoning applies equally to the Narrabri appeal. 15 It is important to emphasise that the "proposed action" here, in each case, is agreed in broad terms to be the extended operation of each existing coal mine, out to 2048 in respect of the Mt Pleasant mine and 2045 in respect of the Narrabri mine. For example, the Minister's reasons at [2] described the Mt Pleasant proposed action as follows: On 28 July 2020, the Department of Agriculture, Water and the Environment (now the Department of Climate Change, Energy, the Environment and Water) (the department) received a valid referral from the proponent to realign the approved Northern Link Road, increase the open cut coal extraction up to 21 Mtpa within the approved Mount Pleasant Project (EPBC 2011/5795) development area, including accessing deeper coal reserves in the North Pit, continued use of the controlled release dam and associated infrastructure as described in the Continuation of Bengalla Mine, NSW, Water Management Plan, (EPBC Act referral 2012/6378), and to extend the life of the mine to 22 December 2048 (the proposed action). (Original emphasis.) 16 Relevantly to the appellant's contentions before the Minister, and on review and appeal, the coal produced from the extension of the Mt Pleasant mine would then be exported to third parties, and it is agreed that it is the actions of the third parties in the combustion of the coal which would produce the majority of GHG emissions. This is clear from the distinction between Scope 1, Scope 2 and Scope 3 emissions as described in the Minister's reasons at [60]-[67]: Request for further information on GHG emissions from the proponent On 10 November 2022, the department sent the proponent a RFI on the GHG emissions associated with the proposed action. The RFI requested information on: a. scope 1, 2, and 3 emissions associated with the proposed action; b. emissions management; and c. consumers of end-product extracted as part of the proposed action. The RFI sought that GHG emissions estimates should be aggregated in million tonnes carbon dioxide equivalent (Mt CO2-e) and defined GHG by reference to section 7A of the National Greenhouse and Energy Reporting Act 2007 (Cth). It also defined scope 1, 2 and 3 GHG emissions by reference to the department's National Greenhouse Accounts Factors workbook, which categorises emissions as follows: a. Scope 1 - direct emissions are produced from sources within the boundary of an organisation and as a result of that organisation's activities (e.g. fugitive emissions from a coal extraction at a mine) b. Scope 2- indirect emissions which occur outside of the boundary of an organisation from the generation of electricity that is consumed by the organisation c. Scope 3 - indirect emissions, other than electricity, which occur outside of the boundary of an organisation as a result of actions by the organisation (e.g. the burning of the product coal from the proposed action by a third party to make steel or generate electricity). Response to RFI Question 1: Scope 1, 2, and 3 emissions associated with the proposed action On 30 November 2022, the proponent responded to the department's RFI about the projected emissions associated with the proposed action. Scope 1 emissions from the proposed action account for approximately 1.8% of total emissions from the proposed action and are expected to occur through the combustion of diesel (43%) and the release of fugitive emissions (54%). Scope 2 emissions from the proposed action come from electricity consumption and represent 0.2% of the proposed action's total projected emissions. The majority of the emissions associated with the proposed action are scope 3, deriving from the combustion of saleable product coal by third parties within Australia and overseas. The proponent's full breakdown of the emissions associated with the proposed action is set out in Table 2 below. Table 2: Proponent's estimate of GHG emissions associated with the proposed action (Mt CO2-e) Scope 1 Scope 2 Scope 3 Total (Scope 1, 2 & 3) Australia Overseas Australia Overseas Annual average 0.4 0.0 1.1 19.1 1.5 20.6 Total 9.5 1.2 27.7 496.5 38.3 534.8

The proposed action's total average annual emissions (Scope 1, 2, and 3) within Australia represent 0.25% of Australia's annual emissions for the 2020 reporting year. The proposed action's total average annual emissions (Scope 1, 2 and 3) within Australia and outside Australia combined represent 0.042% of global emissions in 2019. I noted that the proponent's estimate of total emissions over the life of the proposed action (534.8 Mt CO2-e) is significantly lower than the 874.17 Mt CO2-e estimate provided by EJA in their initial letter to me. The department advised that EJA sourced emissions data from the proponent's publicly available EIS. The EIS, developed for both NSW and Commonwealth assessment processes, contains emissions data for the proposed action (Mount Pleasant Optimisation Project, EPBC 2020/8735) and the existing Mount Pleasant Coal Project (2011/5795). The Mount Pleasant Coal Project (2011/5795) was approved under the EPBC Act in 2012 and is a separate and distinct action from the proposed action which is the subject of this reconsideration decision. For this reason, I was satisfied that the emissions estimates provided by the proponent totalling 534.8 Mt CO2-e are the correct estimates for the proposed action. (Original italics, original and added emphasis.) 17 On the appeal, the figure of 534.8 Mt CO2-e emissions was not challenged. 18 The parties differed in their interpretation of the Minister's reasons for confirming the controlled action decisions, and differed about whether her reasons could, or should, be read as having addressed the matters she needed to address. Ultimately, our conclusion about which of the parties is correct in their interpretation of the Minister's reasons is the basis for the dismissal of four of the five grounds of appeal. The fifth ground of appeal cannot succeed in part because the appellant's interpretation of the Minister's reasons is incorrect, but in part on other bases, as we explain. 19 While the Minister concluded she was not satisfied that the power in s 78(1)(a) should be exercised to revoke the controlled action decisions and substitute new ones with a wider range of controlling provisions (because of a wider range of relevant impacts), the Minister did make a series of findings along the way to this conclusion which, as senior counsel for the Minister submitted, provide essential context for considering the remaining grounds of judicial review that are pressed on the appeal. 20 It is fair to say this issue about the correct interpretation of the Minister's reasons did not loom as large in the Minister's written submissions on the appeal, nor in the submissions before the primary judge. Nor was this issue as prominent in the reasoning of the primary judge. However, the differing interpretations of the Minister's reasons were explored in oral argument on the appeal, and we consider this issue to be determinative of some of the grounds of appeal against the appellant. 21 It is therefore necessary to describe the Minister's reasoning process in some detail, at least as it relates to the grounds of appeal. 22 First, on the question whether the voluminous information produced by the appellant in support of its reconsideration request was properly characterised as "substantial new information", the Minister accepted it was. The Minister accepted: (a) In relation to world heritage values of declared World Heritage property (ss 12 and 15A of the EPBC Act), that the appellant had identified substantial new information contained in over 470 documents. (b) In relation to National Heritage values of a National Heritage place (ss 15B and 15C of the EPBC Act), that the appellant had identified substantial new information contained in over 230 documents. (c) In relation to the ecological character of declared Ramsar wetlands (ss 16 and 17B of the EPBC Act), that the appellant had identified substantial new information contained in over 50 documents. (d) In relation to listed threatened species and ecological communities (ss 18 and 18A of the EPBC Act), in the controlled action decision, the delegate identified ss 18 and 18A as controlling provisions however the delegate did not consider the potential climate change "flow-on effects" of GHG emissions or impacts of GHG emissions on protected matters. The Minister accepted that the appellant had identified substantial new information contained in over 2000 documents. (e) In relation to listed migratory species (ss 20 and 20A of the EPBC Act), that the appellant had identified substantial new information contained in over 150 documents. (f) In relation to the environment in a Commonwealth marine area (ss 23 and 24A of the EPBC Act), that the appellant had identified substantial new information contained in over 540 documents. (g) In relation to the environment in the Great Barrier Reef Marine Park (ss 24B and 24C of the EPBC Act), that the appellant had identified substantial new information contained in over 13 documents. 23 The appellant also identified, as part of the "substantial new information", reports of authoritative national and international organisations and independent expert reports addressing the analysis and conclusions of the reconsideration request. The Minister set out a number of extracts from those reports in the section of her reasons dealing with the information submitted by the appellant. 24 The Minister's principal reasoning occurred in that section of her reasons dealing with the MNES of world heritage values of declared World Heritage property (ss 12 and 15A). As we explain, the Minister then confirmed and carried over her reasoning from this section into the sections dealing with other MNES. 25 At [97] of her reasons the Minister found: I found that this information is substantial new information because: a. much of the information contained in the request was not before the delegate and so is considered new information; and b. the information is of substance and is not trivial or inconsequential, and demonstrates that climate change has various effects on this protected matter. (Emphasis added.) 26 And at [99] of her reasons: The information in the reconsideration request identifies that climate change and its flow-on effects are affecting or will affect the ecology of the identified declared World Heritage properties. Based on the information provided, the extent of the effects appears to vary between the properties, reflecting their unique natural environments. In summary, World Heritage properties containing ecosystems and/or species with low temperature range tolerances (e.g. alpine and coastal environments) are more susceptible to climate change. In general, climate change reduces the resilience of ecosystems due to the increased risks from a range of factors including: a. altered (or reduced) abundance and distribution of species critical (and/or unique) to the ecological integrity of the property; b. altered hydrological flows causing increasing incursions of saltwater into freshwater (and the reverse) damaging important feeding and breeding habitat; c. invasive/pest species gaining a greater foothold; d. extreme temperature events causing heat stress to susceptible plants and animals (e.g. the Spectacled Flying Fox Pteropus conspicillatus); and e. altered or inappropriate fire regimes associated with temperature extremes. (Original italics, emphasis added in bold.) 27 The parts we have emphasised in bold demonstrate, in our opinion, that these passages, and the others like them in this section of the reasons, should be read as positive findings by the Minister, favourable to the position put by the appellant in its reconsideration request and the supporting material. 28 This is confirmed by the recitation used by the Minister in determining each of the subsequent MNES identified by the appellant. For example, at [139], concerning National Heritage values of National Heritage places (ss 15B and 15C): I accepted the department's advice that the information shows that climate change is having or will have adverse effects on the flora, fauna and ecosystems of the identified National Heritage places. This will in turn have adverse effects on the National Heritage values of those places. (Emphasis added.) 29 In argument especially on appeal ground 2, the appellant criticised the use by the Minister in her reasons at various points of the term "will have", "will … affect" and "will cause". The appellant contended these phrases indicated the Minister had not engaged with the likelihood or real possibility aspect of s 78(1)(a)(ii). However, read fairly and in context, the Minister uses these expressions because she is making a positive finding of impact from global emissions upon MNES by reason of the climate change caused by those emissions. She uses "will" because she has assessed the impact to have a high level of certainty. In other words, passages such as this are favourable to that aspect of the contentions put to the Minister by the appellant. 30 Having made those findings, by the heading immediately after [99] of her reasons the Minister then turned to the statutory question asked of her by s 78(1)(a), and expressed that question correctly: Does the information relate to the impacts that the proposed action has or will have, or is likely to have, on the world heritage values of a declared World Heritage property? (Original italics, original underline.) 31 In this heading, the Minister used "relate to" instead of the statutory term "about", but nothing turns on this. The meaning of the two terms is the same in this context. 32 At [100] of her reasons, the Minister repeated her findings about the adverse effects of climate change on the flora, fauna and ecosystems of the World Heritage properties she had listed at [98]. She then correctly identified the next critical step about which she must make findings: Whether the information relates to adverse impacts of the proposed action on this protected matter is discussed below. (Emphasis added.) 33 It is at this point that the Minister, correctly, turned to the terms of s 527E of the EPBC Act, which provides: 527E Meaning of impact (1) For the purposes of this Act, an event or circumstance is an impact of an action taken by a person if: (a) the event or circumstance is a direct consequence of the action; or (b) for an event or circumstance that is an indirect consequence of the action - subject to subsection (2), the action is a substantial cause of that event or circumstance. (2) For the purposes of paragraph (1)(b), if: (a) a person (the primary person) takes an action (the primary action); and (b) as a consequence of the primary action, another person (the secondary person) takes another action (the secondary action); and (c) the secondary action is not taken at the direction or request of the primary person; and (d) an event or circumstance is a consequence of the secondary action; then that event or circumstance is an impact of the primary action only if: (e) the primary action facilitates, to a major extent, the secondary action; and (f) the secondary action is: (i) within the contemplation of the primary person; or (ii) a reasonably foreseeable consequence of the primary action; and (g) the event or circumstance is: (i) within the contemplation of the primary person; or (ii) a reasonably foreseeable consequence of the secondary action. 34 There is no doubt this provision is definitional. All counsel accepted it applied across the EPBC Act, although in different statutory contexts and often combined with various adjectives before the word "impact" (such as "significant", "adverse", "beneficial" etc). 35 At [104] of her reasons, the Minister made what we consider to be the first of two positive findings that demonstrate she was satisfied that the substantial new information could be about the indirect consequences (or impacts) of taking the proposed action. At [104] of her reasons, the Minister linked the combustion of coal and/or gas with the adverse effects of climate change on MNES, being effects she had already accepted at [99] of her reasons: I considered that the request contains information which demonstrates in a general sense that climate change from anthropogenic sources of GHG emissions has and/or will have physical effects on protected matters. In particular, I accepted that the combustion of coal and/or gas on a global scale results in GHG emissions, which increases the effects of climate change, including the regularity, scope and intensity of climate hazards. I accepted that these effects of climate change will adversely affect the MNES named by EJA in their application. (Emphasis added.) 36 Therefore, by this point, the Minister had accepted the existence of a causative link between the global combustion of coal and/or gas and the effects of climate change and had also accepted that unabated climate change is having or will have adverse effects upon MNES. These findings were expressed as a matter of certainty not as matters of likelihood or possibility. However, there remained the question posed by the legislation as to whether the new information that had been provided indicated that the proposed action itself will have or is likely to have an impact upon MNES. That is to say, the Minister had to reach a conclusion as to whether the new information that had been provided related to an impact on MNES that the proposed action itself would have or was likely to have. Given the earlier findings about the certainty of the causal connection on a global scale, the answer to that question required findings as to the likely extent, if any, of the contribution of the proposed action to the accepted global impact. 37 It was in that context that at [105] of her reasons, the Minister made the following second and critical finding: To the extent that the information may be relevant to the physical effects of climate change caused by the proposed action, the request contains information about emissions resulting from the combustion by third parties of the coal to be extracted in the proposed action. I accepted the department's advice that, having regard to the information provided by EJA and through the section 78B consultation process, the physical effects of climate change on the world heritage values of declared World Heritage properties (which the request is about) are, if anything, indirect consequences of the proposed action: they are events or circumstances that are removed in time and distance from the taking of the action, which is the extraction of coal. (Original italics, emphasis added in bold.) 38 Located as it is after the heading which correctly framed the question under s 78(1)(a), and after the reference to s 527E, we are comfortably persuaded that the correct understanding of the Minister's reasoning here is that she was making a conditional positive finding as to indirect consequences. The finding was to the effect that the new information showed that there were indirect consequences of the proposed action if they were demonstrated to be of significance for the accepted global effect. It anticipated the Minister's later reasoning (see below) which concerned whether a decision not to approve the proposed action would have any substantial consequence for the certain causative link between aggregate global combustion of coal and/or gas and climate change with consequent certain impacts of that global consumption upon MNES in Australia. 39 In the passage quoted above, the Minister was expressing an affirmative state of satisfaction that if the new information showed the proposed action to be of significance for the accepted global effect then the adverse effects she had described in [99] (eg altered or reduced abundance and distribution of species critical and/or unique to the ecological integrity of the property) would be an indirect consequence of taking the proposed action. The words "are, if anything" reflect the conditional character of the finding at this point in the reasoning. They do not transform this whole passage, read fairly and in context, into a hypothetical alternative. Rather, they presage what is to follow which is a consideration of the likely indirect impact of the proposed action upon MNES undertaken on the basis that the global effects are accepted as being certain. It is finding, in effect, that the answer to the question as properly posed depends upon whether the new information demonstrates actual or likely indirect impact by contributing to the accepted global impact. 40 In other words, the Minister did, we are satisfied, work through the task in s 78(1)(a), including whether she was satisfied that the new information related to the effects that the extended operation of the coal mine would have, or was likely to have (to paraphrase) on MNES. She found, in our opinion, that the action would have indirect impacts on MNES if it contributed to the accepted global impact to a degree that fell within the concept of a "substantial" cause. Her language, considered in context, expresses a state of satisfaction that relevant "impacts" (being impacts of the proposed action) were more than likely (in the sense of being a real possibility) if the new information was to the effect that the proposed action was likely to contribute substantially and thereby have the requisite 'impact'. It was a conditional finding of impact which depended upon the outcome of further analysis (which was to follow) concerning whether the new information related to impact of the proposed action upon global emissions (which were accepted as having an impact upon MNES). 41 Read fairly and in context, the Minister's reasons disclose she was satisfied to a considerable degree of certainty, consistently with the departmental advice to her, that the extension of operations of the coal mine would have, or was likely to have (to paraphrase) an impact on all of the MNES identified by the appellant in its reconsideration request if it was shown that they contributed to the extent of global emissions. Although [105] only concerned the values of World Heritage properties, the Minister subsequently applied the same reasoning to the other MNES identified by the appellant. 42 The Minister's reasons disclose she also considered ss 78(1)(aa) to (d), but that aspect of her reasons is not impugned on the appeal. 43 It is appropriate here to note that the Minister accepted that "likely", when it is used in these kinds of provisions in the EPBC Act, does mean a real and not remote possibility, and not some higher or more demanding threshold. No party on this appeal contended for any different approach, and so we proceed on that basis. 44 Having made the conditional finding as described to the effect that she was satisfied that the extended operation at the coal mine "would have" an impact on MNES, the Minister then turned to the limitations in respect of indirect consequences, which are imposed by s 527E(1)(b) of the EPBC Act. The Minister had set this provision out at [102] of her reasons. We have set the provision out at [33] above. All parties to the appeal accepted that limitation was properly described as involving a causal link, and no party disputed that the adjective "substantial" imported a qualitative assessment to the nature of the causal link that the Minister must be satisfied exists. 45 In our opinion, the Minister's reasons demonstrate she understood the need for a causal link, one which could be described as "substantial", between the taking of the action and the adverse and indirect impact on MNES. That is why she uses the word "therefore" at the start of [106]: Therefore, I determined that for the information in the request to be about the impacts of the proposed action under section 527E of the EPBC Act, the proposed action must be a substantial cause of the physical effects of climate change on the world heritage values of a declared World Heritage property. 46 Before we turn to the Minister's findings on substantial cause, it is appropriate to note what was not argued on this appeal. Neither in grounds of review before the primary judge, nor in grounds of appeal before this Court, was any argument developed by the appellant about a fundamentally different interpretation of the phrase "substantial cause" in s 527E(1)(b) to the one adopted by the Minister. There was no developed argument about whether the phrase had a qualitative meaning that could not, for example, be reduced to an arithmetical analysis, where the cause was a global one (combustion of coal) and the impacts were also global, although relevantly felt across a wide range of MNES within Australia. As we explain in relation to ground 5, there were some assertions made before the primary judge that "substantial cause" had a different meaning. However, they were not developed in any detailed way, and they certainly did not amount to an argument that the approach taken by the Minister was not open because it involved a misconstruction of that phrase. 47 At [107], the Minister stated that she found the proposed action was not a substantial cause of the stated physical effects of climate change on the world heritage values of declared World Heritage properties. Later in her reasons, she applied this reasoning to the other MNES identified by the appellant. 48 At [107] she then gave two bases for her conclusion: As explained below, this is because: a. the information does not demonstrate that the proposed action will cause any net increase in global GHG emissions and global average temperature (and so, any physical effects of climate change on the world heritage values of declared World Heritage properties). I considered that whether this will happen is subject to multiple variables; and b. even if that were demonstrated, any contribution from the proposed action to global GHG emissions would be very small. It is therefore not possible to say that the proposed action will be a substantial cause of the physical effects of climate change on the world heritage values of declared World Heritage properties. 49 Thus, on the first basis, the Minister used the concept of "net increase" as a measure of the proportional connection between the proposed action and overall or worldwide GHG emissions, recognising the scientific material establishes those emissions are responsible for all of the effects the Minister described and accepted at [99] of her reasons in relation to World Heritage property. Contrary to the appellant's submissions, in this passage at (a), the Minister assumed the action will proceed. 50 The second basis starts with an assumption, contrary to the Minister's first basis, that a "net increase" in global GHG emissions and global average temperature from the combustion of coal produced by the extension of the mine could, or would, occur. Making that assumption, the Minister then engaged in three distinct arithmetical calculations, which she set out at [121]-[124], and it was these calculations that led her to the conclusion that any contribution to worldwide GHG emissions and global average temperature from the action would be "very small". Again, contrary to the appellant's submissions, this reasoning proceeded on the premise that the action will be taken. 51 Those three distinct calculations were, at [122] of the Minister's reasons: In response to a request by the department for information, the proponent provided information demonstrating that the average total annual GHG emissions (scope 1, 2 and 3) from the proposed action represents approximately 20.6 Mt CO-2e or 0.042% of global annual emissions in 2019. The proponent used Climate Watch's Historical GHG Emissions 2019 data, the latest data available at the time, as the basis for its calculations, consistently with the department's request for information. 52 At [123], the Minister continued: Further, the proponent estimated, in response to the same request for information, that the total GHG emissions associated with the project would be approximately 534.8 Mt CO-2e. I noted that the department estimated that the likely increase in global temperature that could arise from the proposed action's estimated total GHG emissions, in a scenario where it could be shown that the proposed action would result in a net increase in global GHG emissions and global average temperature, is approximately 2.4x10-4 0C or 0.000240C. The department prepared this estimate assuming a one-for-one relationship between temperature and tons of GHG emissions, based on the information EJA provided about findings by the IPCC Working Group I that the relationship between anthropogenic CO2 and global temperature has thus far been approximately linear. 53 At [124]: The IEA Coal 2022 report also noted global coal consumption in 2022 was predicted to reach 8 025 million tonnes. The proposed action's maximum annual output is 21 million tonnes per annum (Mtpa) and this represents 0.26% of the global coal consumption that was predicted for 2022. Further, the IEA Coal 2022 report predicts global coal consumption will reach 8 038 Mt in 2025. 54 These paragraphs are impugned by ground 5 on irrationality grounds. The essential criticism is that the Minister used fixed historic data with fixed levels of global annual GHG emissions (the data coming from 2019, provided by the second respondents), and that reasoning based on this kind of data took as its starting an assumption that total future emissions will be the same or worse, when the objective evidence suggested that in many scenarios there may well be a reduction in global emissions (making the contribution from this coal mine proportionally greater), depending on which scenario is posited. In addition, by ground 3, the appellant contended the Minister adopted this reasoning in a circumstance where the proposed action did not occur (that is said to be the construction error raised by ground 1). That assumption (or finding) is said to be irrational because, the appellant contended (at [55] of its written submissions in both appeals): The most that could rationally be said about what the substantial new information showed concerning the future with and without the proposed actions was this: that there was a range of lower-emission scenarios that were really possible without the action, but were not possible with it - because "with it" must assume a decades-long market for seaborne coal, whereas "without it" does not need that assumption - and therefore that certain adverse effects on matters protected will occur in every scenario where the action is taken, but will not occur in some scenarios where it is not: J[135] (proposition 3) (A.6.139). (Original italics, original emphasis omitted, emphasis added in bold) 55 In other words, ground 3 proceeds on the basis that the three calculations in the Minister's reasoning concern a "world" where the proposed action is not taken. As we explain, that is an incorrect understanding of the Minister's reasons. 56 At [125] of her reasons, the Minister then explained why, using the language of s 527E(1)(b) about the indirect impact of the action on World Heritage properties through global GHG emissions and the (accepted) contribution of those emissions to climate change, she is not satisfied that the (indirect) impact "will be" a substantial contributor to those emissions. It is important here to note that s 527E(1)(b) requires that "the action is a substantial cause of that event or circumstance". The Minister's reasons are faithful to the way this part of s 527E(1)(b) is expressed: In view of the amounts outlined at paragraphs [122] to [124] above, I found that the amount of coal to be combusted from the proposed action, and the possible increase in net global GHG emissions and global average temperature that would result from combusting this amount of coal, are very small. I concluded that the proposed action would not be a 'substantial' cause of the physical effects of climate change on World Heritage properties. 57 Then, at [126]: The request asserts that 'there is an approximately linear relationship between cumulative anthropogenic CO2 emissions and global temperature, such that every tonne of CO2 emissions adds to global warming', and I accepted this. However, for the reasons discussed above, I did not accept that the contribution this action makes to emissions will be a 'substantial cause' of the physical effects of climate change on the world heritage values of declared World Heritage properties. (Emphasis added.) 58 Paragraph [126] of the Minister's reasons further demonstrates, in our opinion, that the assumptions made in many of the appellant's grounds of appeal misunderstand the Minister's reasoning. Paragraph [126] is expressed on the basis that the action, being the extension of the Mt Pleasant mine, proceeds, and is responsible, through the third party combustion of the coal which the mine produces, for total GHG emissions of approximately 534.8 Mt CO-2e. 59 Consistently with this, the conclusions in [129]-[130] reflected the two alternative paths of reasoning we have described above, both premised on the action proceeding. 60 As we indicated above, the Minister then proceeded, from [132] onwards, to consider the other MNES under Pt 3 of the EPBC Act, and did so adopting the same reasoning. Her conclusions at the end of her reasons (see [200]-[202]) mirror her conclusions in relation to the world heritage values of declared World Heritage property.

THE PRIMARY JUDGMENT 61 Before the primary judge, in separate judicial review applications for each of the Minister's decisions, the appellant identified ten grounds of judicial review, five of which are pursued on appeal. The appellant relied on both s 39B of the Judiciary Act 1903 (Cth) and s 5 of the Administrative Decisions (Judicial Review) Act 1977 (Cth). At [15] of the primary judgment, the primary judge summarised the thrust of the appellant's argument that many MNES: had been impacted and were likely to be impacted by climate change and that in each case the proposed action is a substantial cause of the adverse effects of climate change on MNES, so as to engage the indirect impact provision at s 527E. 62 An example was developed before the primary judge. This involved the Great Barrier Reef, as a declared World Heritage property pursuant to ss 12-15A of the EPBC Act. At [17], the primary judge describes the "event or circumstance" for the purposes of s 527E as coral bleaching of the Great Barrier Reef, caused by increases in ocean temperatures, in turn caused by global warming. The primary judge said (at [18]): Thus, for the purpose of applying the indirect impact provision at s 527E, the question is whether coral bleaching (the event or circumstance) of the Great Barrier Reef inside the marine environment is an impact of each proposed action (mining and extracting coal) because it is an indirect consequence of that action, but only if the action is a substantial cause of the coral bleaching. And there is a further statutory requirement at s 78: the substantial new information must be about the impacts that each action has or will have, or is likely to have, on a matter protected by a provision of Pt 3. It will be apparent at the outset that the application of the indirect impact provisions of the Act is not straightforward upon judicial review of the Minister's decisions. 63 After providing the factual background to the applications, from [23]-[36], the primary judge summarised the reasons for the Minister's decision. This summary and the primary judge's description of the Minister's reasons in these paragraphs is not in issue in the appeal. 64 At [32]-[34], the primary judge characterised the Minister's reasoning as having two "limbs", which is correct. His Honour also proceeded on the basis that the phrase "likely" means a real or not remote chance or possibility. Although the primary judge described the appellant as having contended for a more expansive meaning, the appellant submitted it had not done so. Nothing turns on this, as the meaning of "likely" was not a contested issue in the appeal. 65 From [61], the primary judge dealt with the ten grounds of review. Before the primary judge, grounds 1-6 were directed to the "net increase issue", being what the primary judge referred to as 'limb 1' of the Minister's reasons. Grounds 7-10 before the primary judge were directed to the "relative contribution issue", being what the primary judge referred to as 'limb 2' of the Minister's reasons. This appeal concerns some review grounds under each limb, namely grounds of review 1, 2, 6, 7 and 10. Where appropriate we deal with the primary judge's reasons under each appeal ground.

CONSIDERATION 66 Without any disrespect to the primary judge, but (we infer) conscious that the issues on the appeal were largely questions of law, the parties concentrated their arguments by reference to the Minister's reasons, rather than the reasons of the primary judge. Accordingly, we will also focus on the Minister's reasoning. As will become apparent, we do not consider the appellant has demonstrated any error in the orders of the primary judge, nor in his Honour's basal reasoning supporting those orders.

GROUND 1: EVALUATION OF IMPACT BY 'SUBSTITUTION REASONING' AND 'NETTING OFF' 67 The appellant describes this ground of appeal as about "substitution reasoning" and "netting off" reasoning, whereby the Minister conducted an inquiry into what might happen if this action does not proceed, but others do instead. The concept of "substitution reasoning" is described at [11] of the appellant's written submissions: The Act does not authorise "netting off" by reference to a counterfactual world in which (1) the action is not taken, but (2) the same events or circumstances are instead the consequences of a different action. (Original emphasis.)

The primary judge's reasoning 68 The primary judge rejected the appellant's contentions that it was not open to the Minister to reason by reference to "a possible counterfactual", and that the Minister was required to reason differently. His Honour found (at [71]) that there: is no express requirement in the Act which compels the Minister to reason in any particular way in order to be satisfied, pursuant to s 78, that revocation and substitution of a controlled action decision is warranted … The statutory scheme requires the Minister to undertake a factual inquiry … 69 The primary judge was also critical of the appellant's case and its lack of engagement with the reasoning of Stone J in Anvil Hill Project Watch Association Inc v Minister for the Environment and Water Resources [2007] FCA 1480; 243 ALR 784 and of the Full Court in Anvil Hill Project Watch Association Inc v Minister for the Environment and Water Resources [2008] FCAFC 3; 166 FCR 54 (together, Anvil Hill). In these decisions, the Court rejected arguments challenging a delegate's decision about the impacts of climate change as being uncertain. 70 While in an outcome sense Anvil Hill supports the primary judge's approach, and the approach of the respondents, the reasoning in the underlying decisions in Anvill Hill was very different. That is because the science establishing the effects of the combustion of fossil fuels on climate change, and climate change's effects in turn on MNES, was nowhere near as well advanced, or accepted, at the time of the delegate's decision in Anvil Hill in 2007, and the delegate in Anvil Hill was not persuaded about the science: see, for example, the delegate's conclusion as extracted at [26] of Stone J's reasons: I found that, while it is clear that, at a global level, there is a relationship between the amount of carbon dioxide in the atmosphere and warming of the atmosphere, the climate system is complex and the processes linking specific additional greenhouse gas emissions to potential impacts on matters protected by Part 3 of the EPBC Act are uncertain and conjectural. In light of this, and in light of the relatively small contribution of the proposed action to the amount and concentration of greenhouse gases in the atmosphere, I found that a possible link between the additional greenhouse gases arising from the proposed action and a measurable or identifiable increase in global atmospheric temperature or other greenhouse impacts is not likely to be identifiable. 71 In contrast, in the present case, the Minister accepted the science concerning the link between additional GHG and identifiable increase in global atmospheric temperature. Compare [104] of the Minister's reasons: I considered that the request contains information which demonstrates in a general sense that climate change from anthropogenic sources of GHG emissions has and/or will have physical effects on protected matters. In particular, I accepted that the combustion of coal and/or gas on a global scale results in GHG emissions, which increases the effects of climate change, including the regularity, scope and intensity of climate hazards. I accepted that these effects of climate change will adversely affect the MNES named by EJA in their application. 72 For our own part, and with respect, we do not see sufficient parallels with the Anvil Hill cases for this to be material on the resolution of ground 1. It is also true that there are parts of the primary judge's reasoning (eg at [79]) that might suggest the primary judge also considered the Minister had addressed s 78(1)(a) by positing what might occur if the action were not undertaken. If the primary judge did take this approach, in our opinion that is likely because a different reading of the Minister's reasons was emphasised for the first time on appeal, especially by the Minister. Neither this, nor the reliance on Anvil Hill, matters, because the primary judge was correct in his conclusion that each of the grounds of review should be dismissed, and therefore his orders were also correct. 73 The notice of appeal in each appeal puts ground 1, and the accompanying particulars, as follows: 1. The learned primary judge erred by holding that ground 1 (J [62]) failed (J [82]), and should instead have upheld ground 1. Particulars a. Having correctly found (J [59]) that the phrase "likely to have" in ss 75(2)(a)(ii) and 78A(1)(a)(ii) meant a "real or not remote chance or possibility," the learned primary judge then erred in: i. finding (J [57], [59], [78], cf. quote at J [63]) that the Appellant's case involved attributing any different meaning to the phrase; ii. finding (J [70], [71]-[74], [76], [80]) that the Appellant's case involved a narrowed or prescriptive approach to factual causation; iii. failing to find (cf. J [76]), given the assessment required by the phrase "likely to have" extended to things that were only a "real or not remote chance or possibility" (as opposed to things that were more likely than not), that assessment of the "impacts" of the proposed action required the Minister to consider all of those likely impacts, rather than (as in fact she did): 1. only some of them; or 2. the impacts monolithically and without differentiation. b. Having correctly found (J [73]) that the factual inquiry required by the statute involved identification of what is the proposed action and what are the events or circumstances that are the indirect consequences of that action, the learned primary judge then erred in finding (J [79]) that it was permissible for the Minister then to negate those events or circumstances that are indirect consequences of the action by positing hypothetical counterfactual scenarios in which those events or circumstances would or might be consequences of other conduct. c. The learned primary judge erred in finding (J [80]-[81]) that existing authority was contrary to the Appellant's submissions. 74 The appellant describes the Minister's state of mind in forming the satisfaction required by s 78(1)(a) as being "not satisfied of any likely net increase in global emissions before net zero, and therefore in the net extent to which matters protected would be adversely affected as a consequence of increased greenhouse gas emissions" (original emphasis). The appellant then refers to the Minister's "substitution reasoning" in which the Minister hypothesised counterfactual worlds in which the proposed action is not taken but the same events or circumstances are a consequence of other actions. 75 The appellant contends that if such reasoning is permissible in the context of ss 78(1)(a)(ii) and 527E(1)(b) then such an approach must be permissible for any other parts of the EPBC Act which deploy the phrase "has or will have" and "is likely to have" and for the direct consequence in s 527E(1)(a). The appellant contends that such an approach is not supported by the EPBC Act and would "substantially undermine" and affect the objects of the Act by limiting the situations where an event or circumstance could result only from a proposed action (not from any other action). Whilst the appellant's case is based on indirect impacts within s 527E(1)(b), the appellant contends that substitution reasoning in respect of direct impacts within s 527E(1)(a) would also be contrary to the EPBC Act.

Ground 1: Resolution 76 As will now be apparent, we reject the premise of this ground, in terms of the correct interpretation of the Minister's reasons. For the first 'limb' set out at [107], the Minister did not refer to a world in which the action of the extension and longer operation of the coal mine did not occur. The Minister reasoned on the basis that the action would be taken, and she accepted all the scientific material put forward by the appellant, together with the advice of her department. The Minister accepted almost all of the appellant's contentions, right up to the question whether the extension and longer operation of the coal mine is a "substantial cause" of consequences such as coral bleaching. It is at this point the Minister rejected the appellant's contentions. The extension and longer operation of the mine, she found, is a cause of these kinds of indirect consequences, but not a "substantial cause" (italics added). This was her reasoning on both limbs set out at [107] - the first through considering global net GHG emissions and global average temperature (if the mine continued to operate) and finding the burning of the coal from this mine would not increase net GHG emissions; and the second through considering the proportional contribution to global GHG emissions from the burning of coal produced by the extension of the mine, on the contrary assumption that the burning of that coal would increase global net emissions. 77 There was no error by the Minister in her construction of the task in s 78(1)(a). To the contrary, the Minister proceeded on the basis that the mine expanded its operation and continued beyond 2040 (2048 in respect of the Mt Pleasant project and 2045 in respect of the Narrabri project). She accepted that if the operation of the mine was likely to make a substantial contribution to the certain effects of global GHG emissions upon climate change (and consequent certain adverse effects upon MNES) then there would be relevant adverse impact and the new information would relate to that impact. In that sense the Minister correctly understood she was assessing the situation if approval was given for the extension of the mine. She was however not persuaded at a factual level that the extended operation of the mine was a substantial cause of these adverse consequences, for the purposes s 527E(1)(b). In substance, to put it another way, the Minister found the GHG emissions causing global warming would predominately be coming from other sources than the extended operation of the Mt Pleasant mine. 78 The appellant's misunderstanding of the Minister's reasoning means that ground 1 must fail.

GROUND 2: ALLEGED MISDIRECTION IN SS 78(1)(A)(II) AND 527E(1)(B): NO CONSIDERATION OF LIKELIHOOD

The primary judge's reasoning 79 This ground is based on an alternative assumption to ground 1. Even if the Minister was permitted to engage in a counterfactual inquiry involving substitution reasoning, the appellant contends the Minister was required "on all the material before her to reason across a very broad spectrum of future scenarios in which the proposed action is taken, but failed to do so" (primary judgment at [83]). 80 The primary judge rejected this aspect of the appellant's submissions "substantially for the reasons given for ground 1", finding that it was open to the Minister to consider the counterfactual scenario and that the Minister is not restricted to considering only scenarios based on an assumption that the proposed action will be taken (at [87] of the primary judgment). 81 The notice of appeal puts ground 2, and the accompanying particulars, as follows: 2. Alternatively, the learned primary judge erred by holding that ground 2 (J [83]) failed (J [92]), and should instead have upheld ground 2. Particulars a. Particular (a) to ground 1 is repeated (note J [87] which incorporates ground 1 reasoning into ground 2). b. The learned primary judge erred in rejecting (J [87]-[91]) the submission at J [84]. c. The learned primary judge erred in rejecting (J [87]-[91]) the submission at J [86]. 82 The appellant contends that the Minister did not ask herself the question posed by s 78(1)(a)(ii) read with s 527E(1)(b), "namely, what events or circumstances were likely to occur (i.e., might as a real possibility occur) as an indirect consequence substantially caused by the action?". Rather, the appellant contends that the Minister asked herself whether the events or circumstances will be a consequence of a net increase attributable to the action (at [107(a)] of the Minister's reasons) and whether the action not proceeding would necessarily mean lower global emissions (at [113] of the Minister's reasons). 83 The appellant contends that if the Minister was permitted to "net off" the adverse effects of the proposed action then she could only have been satisfied, in accordance with ss 78(1)(a)(ii) and 527E(1)(b), "that a putative likely impact was negated by a counterfactual if satisfied that there was no real possibility of the putative event or circumstance happening with the proposed action as a substantial cause" (original emphasis). The appellant contends that this is a result of the primary judge accepting that "likely" in s 78(1)(a)(ii) means a "real or not remote chance or possibility" (at [59] of the primary judgment). 84 The new information demonstrated, the appellant submits, that the "best possible" scenario for emissions, including from the burning of coal, involved in the near future a minimum average temperature increase of at least 1.4°C. The appellant submits the new information also demonstrated that there is a real possibility of increased global temperature rise from 1.5°C to greater than 4°C. It follows that the range of likely events or circumstances, such as coral bleaching (and its adverse effects on the Great Barrier Reef) ranged "from minimal to extinctive". The Minister's reasons are said not to demonstrate any contemplation of such adverse events, and the consequential extreme harm, including extinctive harm, to matters protected. 85 The appellant contends (at [45] of its written submissions) that the Minister's reasoning: failed to grapple with the fact that there is a range of significant adverse effects that will result from further aggregate emissions in even the least-warming scenarios possible with the actions, which will not occur in the least-warming scenarios possible without the actions. For example, there will be massive and widespread adverse effects at 2°C, which will be reached in any scenario in which there remains a substantial seaborne thermal coal market for electricity generation out to 2050, which will not occur in IEA NZE or any of the other 1.5°C C1 scenarios assessed to be feasible by IPCC WGIII (explained further below). (Original emphasis.) 86 Like ground 3, this ground relies on the range of scenarios the appellant contends were presented by the new information, including scenarios where global GHG emissions reduced, which would render the proportional contribution of the extended operation of each of these two mines larger. Unlike ground 3, this ground focusses on the difference between "is likely to" and "will have" in the statutory framework.

Ground 2: Resolution 87 The same answer must be given to this ground as to the first ground, and it must fail because of a misunderstanding of the Minister's reasons. See our reasoning at [76]-[77] above. 88 Read correctly, the Minister's reasons disclose that she undertook the task required by s 78(1), and did appreciate that "likely" in the statutory formulation in s 78(1)(a)(ii) referred to a real and not remote possibility of an event or circumstance occurring. She found (see eg at [100] and [104]) that climate change, driven by "anthropogenic sources of GHG emissions" such as the burning of coal, "is having or will have" adverse impacts on MNES. This reasoning was applied to impacts on world heritage values of a declared World Heritage property, coral bleaching of the Great Barrier Reef being the example used in argument. That is, on these matters, the Minister's finding went beyond likelihood to a higher level of certainty. 89 Where the Minister departed from the appellant's contentions was on whether the extension and operation of each mine is a "substantial cause" of these consequences - eg coral bleaching. The Minister looked at the proportion of the contribution on a global scale and found combustion of coal from the extended operation of the mine was not a substantial cause. This reasoning did not involve the error alleged. 90 As with ground 1, ground 2 must fail.

The primary judge's reasoning 91 From [118], the primary judge considers review ground 6, which is the subject of ground 3 in this appeal. Before the primary judge, the appellant contended that the Minister's reasoning was irrational, rationality being an accepted implied constraint on the lawful exercise of her statutory power. This review ground provided (as set out in the primary judgment at [118]): The finding was affected by irrationality, in that the Minister's reasoning involved illogic, or was insupportable, on the material before her or otherwise: ADJR Act, s 5(1)(f), (h); Judiciary Act, s 39B. (1) The Minister reasoned as follows. The irrationality arises from the final step (e). (a) Premise. Climate change caused by the total accretion of greenhouse gas emissions, before it stops increasing, from sources including (in a universe where it is taken) burning of coal from the Proposed Action will have a significant impact on very many MNES. However… (b) Premise. Whether or not the Proposed Action proceeds, the total level of accreted global greenhouse gas emissions and average temperature at which each stops increasing will be determined by a range of variables. (c) Premise. There are therefore some future scenarios without the Proposed Action that result in total greenhouse gas emissions greater than or equal to some future scenarios with the Proposed Action. (d) Preliminary conclusion. It is therefore not possible to say that total emissions will be higher if the Proposed Action is taken than if the Proposed Action is not taken. (e) Final Conclusion. The significant impacts from greenhouse gas emissions including those from burning the coal from the Proposed Action are not likely significant impacts the Proposed Action is likely to have. (Original emphasis in italics and underline.) 92 From [120]-[125], the primary judge considered the principles relevant to this ground, including judicial consideration of the irrationality review ground. It is not necessary for us to summarise them here, as the principles were not in dispute. 93 From [126], the primary judge then considered the appellant's submissions. The appellant contended (as extracted at [126] of the primary judgment): At the heart of this ground is the Minister's use of scenarios, about which probabilistic reasoning was not rationally possible due to the sheer volume of complex interconnected variables on a global scale over decades, to make probabilistic judgments for the purpose of applying the relevant statutory provisions. The [applicant's] position is that the material before the Minister revealed both (1) a range of feasible (and therefore really-possible) worlds, and (2) the impossibility of rationally determining, from among them, which is more or most likely than the others to occur. (Original emphasis.) 94 At [138], the primary judge correctly summarised the Minister's reasoning on the climate science before her: I need not resolve whether the applicant's six propositions are made out either on the material that was before the Minister or as now sought to be supplemented by the evidence of Dr Gidden. That is because the Minister did not doubt the science of climate change, the causal relationship between the emission of carbon dioxide, the warming of the atmosphere of the Earth and the range of likely impacts on MNES as a result of anthropogenic climate change. Nor did the Minister doubt that the combustion of coal is a significant contributor to total global CO2 emissions. All of that is clear from the Minister's reasons at [14]-[23], when the Minister summarised some of the material contained in the request without disputing the conclusions there identified, at [24] where the Minister noted departmental comment from SOE 2021 and at [96]-[99] where the Minister accepted that the request contained substantial new information which identified that climate change and its effects had affected and will affect MNES. Further, one cannot in this proceeding doubt the integrity of analysis or the conclusions of the various IPCC reports that were before the Minister, nor the credibility of the expert evidence of Dr Gidden, as the second respondent withdrew its notice that he be present for cross-examination. 95 The primary judge rejected the appellant's characterisation of the Minister's reasoning process for the purposes of the irrationality challenge. His Honour repeated some of his findings on the earlier grounds about the Minister not being required by the legislative scheme to reason in any particular way. It is fair to say that his Honour's reasons tend to see much of the appellant's irrationality challenge as leading to "merits review", especially the emphasis on the need for the Minister to consider the range of scenarios arising from the international material on climate change and the inability, on the appellant's contention, of the Minister rationally to choose just one scenario and proceed on the basis that it is the scenario likely to occur, in terms of the levels of emissions, global warming and the effects of climate change on MNES. At [144]-[147], the primary judge explains why his Honour rejects the other irrationality criticisms made by the appellant. It is not necessary to set these passages out. 96 The primary judge decided during the trial to receive provisionally the evidence of Dr Matthew Gidden, a senior research scholar in the Integrated Assessment and Climate Change Research Group of IIASA Energy, Climate, and Environment Program, pursuant to s 57 of the Evidence Act 1995 (Cth). The second respondents maintained an objection to the admission of Dr Gidden's evidence. In concluding on ground of review 6, at [148], the primary judge found that the evidence of Dr Gidden was "not probative on this ground" and therefore declined to receive it into evidence. That ruling is the subject of appeal ground 4. The appellant accepts that if ground 3 does not succeed, ground 4 is immaterial. 97 The notice of appeal in the Narrabri appeal and in the Mt Pleasant appeal are put on identical terms with the exception of the figure in particular b of ground 3, which for Narrabri is 475.03 Mt of CO2-e. 98 The Mt Pleasant appeal puts ground 3, and the accompanying particulars, as follows: 3. Alternatively, the learned primary judge erred by holding that ground 6 (J [118]) was not made out (J [148]), and should instead have upheld ground 6. Particulars a. The "first limb" of the Minister's dispositive reasoning (see J [33]) was that the information before her "[did] not demonstrate" that the proposed action would cause any net increase in global greenhouse gas emissions and global average temperature. b. Leaving "netting off" to the side, the material before the Minister showed 534.8 Mt of CO2-e associated with the proposed action (gross emissions). c. In circumstances where the learned primary judge correctly found (J [59]) that the phrase "likely to have" in ss 75(2)(a)(ii) and 78A(1)(a)(ii) meant a "real or not remote chance or possibility," and assuming that the Minister likewise correctly understood that phrase: i. the "first limb" necessarily involved a finding that the information "[did] not demonstrate" that there was a "real or not remote chance or possibility" of such a net increase; ii. that necessarily, in turn, involved finding that the possibility of the gross emissions not being offset or otherwise reduced to nil or lower was lower than a "real or not remote chance or possibility". d. The material before the Minister, and the evidence of Dr Matthew Gidden, each showed that it was scientifically impossible or irrational to make the findings described in particulars (c)(i) and (c)(ii). e. In these circumstances, the learned primary judge erred in rejecting ground 6 on the basis of the reasoning at J [140]-[147], including in that his Honour erred in finding: i. at J [140], that his Honour's reasoning in relation to ground 1 disposed of ground 6, when the point raised by ground 6 was distinct (and in any case, the particulars to ground 1 above are repeated); ii. at J [141], that the Minister accepted the scientific material referenced in the request, when an aspect of that scientific material was to the effect articulated in particular (d) above; iii. in any case, at J [141], that the fact of the Minister having accepted the scientific material referenced in the request was an answer to ground 6, when it was not; iv. at J [142], that the scientific material did not address the statutory question for the Minister, when (as outlined in particulars (c)-(d) above), it did; v. at J [143], that the ground amounted to merits review; vi. at J [145]-[146], that the Minister had not engaged in probability reasoning, or the Appellant had misunderstood her reasons. (Original italics.) 99 As it did before the primary judge, the appellant contends that the Minister's reasons rest on a "fatalistic premise" that it makes no difference to climate change whether or not the proposed action is permitted because if it is refused, an equivalent amount of coal will still be burned. The appellant contends that this premise is inconsistent with the findings in the Sixth Assessment Report of Working Group I of the Intergovernmental Panel on Climate Change (WGI AR6) and the Sixth Assessment Report of Working Group III of the IPCC (WGIII AR6) which shows there are feasible scenarios where a sharp reduction and cessation in emissions from coal combustion result in less harmful outcomes than if coal continues to be extracted and burned. 100 The appellant contends that if, contrary to ground 1, the Minister was permitted to "net off" and the Minister did, contrary to ground 2, consider any real possibility of adverse circumstances or effects occurring as a consequence of the action but not occurring without it, then the Minister's reasoning was irrational. That is because of her assumption that total emissions will be the same or worse in every "really-possible future" without the action. The appellant contends that the rational conclusion about what the new information showed about a future with or without the action was: that there was a range of lower-emission scenarios that were really possible without the action, but were not possible with it - because "with it" must assume a decades-long market for seaborne coal, whereas "without it" does not need that assumption - and therefore that certain adverse effects on matters protected will occur in every scenario where the action is taken, but will not occur in some scenarios where it is not. (Original emphasis, citations omitted.) 101 As we understand the argument, the vice from the appellant's perspective is that this irrational reasoning led the Minister to view the contribution of the extended operation of the coal mine as much smaller, arithmetically and proportionally, than it could or should have been viewed had the Minister paid sufficient attention to the lower-emission scenarios in the material submitted by the appellant, which it contended were more likely without the action (ie if the extended operation proposal were refused).

Ground 3: Resolution 102 This ground also fails because the appellant's submissions about the Minister's reasoning process are not correct. As the second respondents submitted, and the primary judge found (at [142]), the question posed by s 78(1)(a) concerned cause and effect. As we have sought to explain, the Minister's reasons accepted much more of the appellant's underlying contentions about the effects of climate change, and the contribution of the burning of coal to climate change, than the appellant's submissions on appeal may have suggested. What the Minister did not accept was the "substantiality" of the causal link for the purposes of s 527E(1)(b). 103 When the Minister rejected the substantiality of the causal link in respect of the proposed action, she identified (at [107]) two alternative methods, or 'two limbs', of testing how substantial the asserted causal link was. It was only at certain points in her reasoning on the first limb that the Minister took as her premise that the coal mine did not extend its operation and producers purchased coal from other suppliers: see [115]-[116] of the Minister's reasons. As the second respondents submitted, there was ample material before the Minister on which she could rely for this reasoning, including the IEA Coal 2022 report. Choices of which material was probative in her formation of a state of satisfaction was for the Minister. 104 Contrary to the appellant's submissions, in passages such as the one at [113] the Minister did not engage in substitution reasoning - that is, she was not asking herself whether other coal mines, and the consequent burning of coal produced, would be substituted for the output from the extension of the operations of the Mt Pleasant coal mine. The same proposition applies to her reasoning on the Narrabri project. Rather, the Minister pointed to other kinds of potential contributors to adverse effects on MNES caused by global warming. So much is clear from the last sentence of [113]: That [referring, in my opinion to the effects of climate change on MNES] will be subject to a range of other factors, including the level of emissions from sources other than the proposed action. 105 The last part of this sentence refers, in our view, to other emission-producing activities, and is not restricted to the burning of coal. Again, these were all matters legitimately within the purview of the Minister and there is no irrationality in the approach taken. 106 As we have explained, in the alternative, or 'second limb' the Minister concluded that the proportional contribution from the proposed action to global GHG emissions, if there was one, would be very small: Minister's reasons at [107(b)], and then at [121]-[126]. Absent any developed challenge to the correct meaning and application of the phrase "substantial cause", there is nothing inherently irrational in the approach the Minister took using arithmetical calculations, and proportions. 107 As the primary judge found and the respondents contended, and provided she applied the statute correctly, it was for the Minister to evaluate what aspects of the information before her she found most persuasive about any causal link between the extended operation of the mine and indirect adverse consequences on MNES. On any view, including on the appellant's case to the Minister and then on review and appeal, there were a wide variety of scenarios about how much coal would continue to be burned around the world and by whom, where the coal would be sourced from, whether with or without the burning of coal global emissions would increase or decrease, what the likely rate of global warming would be, and the range of adverse effects of global warming on MNES. 108 There is nothing irrational in the Minister's reasoning at [107], nor the way she explains her evaluation in more detail at [108]-[120], and then at [121]-[126]. The primary judge was correct to reject this ground, for the reasons his Honour gave at [138]-[147]. 109 Ground 3 fails.

GROUND 4: ADMISSIBILITY OF DR GIDDEN'S EVIDENCE 110 Ground 4 fails by reason of the failure of ground 3. The appellant accepted this would be the case.

GROUND 5: THE STANDARD OF "SUBSTANTIAL CAUSE" IN S 527E(1)(B) 111 By ground 5, the appellant challenges the primary judge's conclusions that grounds of review 7 and 10 failed. Both ground of review 7 and ground of review 10 concerned the Minister's reasoning on "substantial cause" in s 527E(1)(b). 112 Ground of review 7 below was couched as a misdirection on the Minister's part by limiting the statutory concept of "substantial" to numerical significance (as extracted at [149] of the primary judgment): The Minister misdirected herself by determining whether a cause was "substantial" in s 527E(1)(b) by reference solely to a criterion whether it had "very small" numerical significance. 113 Ground of review 10 below impugned the Minister's reasoning on substantial cause through an irrationality lens. The primary judge described the "refined" contention on this ground at [160], a description not contended on the appeal to be inaccurate: The complaint of irrationality turns on the Minister's reasoning "based on fixed proportions arrived at by using deterministic fixed denominators when dealing with the likelihood [of a] future" where there is a large spectrum of possible scenarios. 114 The primary judge rejected ground of review 7 and found (at [154]-[155] of the primary judgment): Whether a proposed action is a substantial cause of an indirect event or circumstance turns upon identification of the content of the proposed action, the event or circumstance and the chain of reasoning that is necessary to conclude that the statutory causal relationship exists. So understood, it is an error to construe substantial in isolation: the inquiry is about substantial cause of one or more indirect events or circumstances, the answer to which will be revealed by the particular facts and circumstances under consideration. In some cases, numerical significance may be insufficient. In others, a small numerical significance may have large consequences. The interrelationship of particular actions, identifiable events or circumstances and attribution of substantial cause is a factual matter for the Minister. Further, the Minister did not make the error that is attributed to her. At [102], the Minister set out the relevant provisions of s 527E without qualification or refinement. At [106], she correctly reasoned that she must be satisfied that the proposed action is a substantial cause of the effects of climate change on the world heritage values of World Heritage properties. From [121], she applied that test, on the second limb of her reasoning, by reference to information in her brief about the average total greenhouse gas emissions from the proposed action at [122] and the proponent's estimate that the quantity of coal to be extracted from the proposed action would result in a net increase in global greenhouse gas emissions and global average temperatures of approximately 0.00024°C. On those facts, the Minister concluded at [125] that the possible increase in net global greenhouse gas emissions and total average temperature resulting from the proposed action was "very small" and on that basis the proposed action would not be a substantial cause of the identified physical effects of climate change. Put simply, that reasoning was open to the Minister and reveals no error on her part in misunderstanding the substantial cause requirement of s 527E. The Minister did not in her reasons equate that requirement with large or numerically significant. 115 The primary judge rejected ground of review 10 in the following terms (at [161] of the primary judgment): I reject the submission. Whilst the Minister employed 2022 figures as set out in the Coal 2022 Report, for predicted global consumption of coal of 8025 Mtpa and a further prediction of global consumption of 8038 Mtpa in 2025, it was not irrational for her to do so by ignoring, on the applicant's argument, that a different denominator, reflecting "dramatic decreases in coal used for electricity generation over the period to 2040" would produce a different result, and that it was not open in that circumstance to adopt "snapshots" from individual years. The Minister proceeded on material that was before her, disclosed her reason for doing so and there is nothing in that which bespeaks of legal irrationality, as distinct from the applicant's strong disagreement with how the Minister reasoned.

Ground 5: Resolution 116 The appellant's contentions on this ground of appeal also centre on the variety of "scenarios" which the material before the Minister indicated could occur in the foreseeable future, and the proposition that the scenarios could vary (as described at [61] of the appellant's written submissions): from (1) a few hundred gigatonnes of CO2-e emissions before global net zero (of which emissions from each action would comprise a substantial proportion), keeping warming to 1.5°C, up to (2) thousands of gigatonnes (of which the emissions from each action would comprise a miniscule proportion), and warming of more than 4°C above pre-industrial levels. 117 The appellant contends the potential variations demonstrate why the Minister's reasoning was irrational: she used "fixed denominators" from 2019 data on global emissions and 2022 data on global coal consumption, being the latest available data at the time, but not being data which, when the appellant's new information was taken into account, could be confirmed as accurate or even reliable denominators into the future: It is irrational to select as a divisor an unchanging historical figure to perform a future-looking exercise in which the value of the divisor must change. The primary judge erred in holding otherwise. (Footnote omitted.) 118 In opening this ground on the appeal, senior counsel for the appellant put the argument in the following terms (at TS 10-11): Ground 5 is that when she got to the substantial cause part of the reasoning, she, in effect - and this is if grounds 1 to 3 are not material - there was a separate error affecting that part, which is that she reasoned by reference to a denominator, that is, the total emissions in a world in 2019 or 2022 which can be fixed by reference to facts and used that to produce a fraction where the numerator was the total emissions from this mine 25 years into the future. And what we will seek to demonstrate by reference to the material is that that was not an exercise which could conform to the statutory requirements, and her conclusion that, therefore, any net increase is or are very small was reflective of thinking that this was a singular and definite fraction, whereas, in fact, it was a dynamic, and I won't try and develop that any more until I come to the material and can show your Honours. COLVIN J: Is that to say that the uncertainties of the future were not brought to account, you would say, by that fraction calculation? MR NEKVAPIL: Yes. What I - I will show your Honour some charts which show that coal use up to 2019 increases and increases, and so then if you pick as the denominator a point right at the top of that arc, in effect, what you're saying is, "I want to measure this as a proportion of the worst possible point we've got to in terms of total emissions", but then the numerator being the emissions from the mine is 25 years into the future, and that's the period of uncertainty where - and I will show your Honour this - it becomes much clearer, at least to me with looking at charts, but if current policies proceed, well, that's a fairly rational exercise because coal use steadily increases or, rather, fossil fuel use steadily increases, whereas, on the best available scenarios, it plummets, and so what fraction of the future 25 years of emissions will 534 megatons be? Well, it depends on how we do and therefore it's not an appropriate method, we would say, or an appropriate understanding of the situation to just say, "I will take it as a fixed fraction based on where we're at today". 119 When senior counsel returned to oral submissions on this ground at the end of the first day of the appeal, he put the contention this way (TS 73): … the dynamic nature of the problem posed by likely events or circumstances wasn't, at least in these circumstances, something that could be answered, properly understanding the test, by the kind of exercise done, which was to have a fixed proportion as though it were a singular thing. And we would say it's really reflective of the same kind of reasoning which supports our ground 2, which is to treat it as though these are concepts without that dynamic involved, as though it's just, "Well, the future will be much the same as the past, and therefore I can use that as the denominator and that as the numerator." 120 We do not accept the appellant's submissions on ground 5. As a preliminary matter, the appellant asserted there was an interdependence between the two limbs of the Minister's reasoning in [107], but as we have explained this is an erroneous reading of the Minister's reasons. The 'two limbs' in [107] are independent of each other, and the Minister's submissions to this effect on the appeal should be accepted. So much is apparent from the commencing words "even if" in [107(b)] of the Minister's reasons. 121 As we have sought to demonstrate with the extracts from the argument above, the appellant's main point on ground 5 was, as developed, not a statutory construction point about the meaning of the phrase "substantial cause". Rather it was a factual attack on the Minister's failure to consider the identified range of future scenarios, in the context of clear uncertainty (it was contended) about which scenario might play out, in terms of the actual global levels of emissions and warming. 122 Thus, although at one point in the grounds of review before the primary judge (especially ground of review 7) and in the initial ground of appeal, the appellant appeared to be making a construction argument about the meaning of "substantial cause", the argument as developed was in truth about the Minister's failure to consider the range of possible scenarios that could eventuate while the coal mine was in its extended and expanded operation period, being the "action" under consideration. Senior counsel for the second respondents also made this point in final oral submissions, and we agree. 123 The second respondents contended the method used by the Minister in the present circumstances was similar to the one found to be without error by Stone J at trial in Anvil Hill (without criticism on appeal) at [40]: The applicant criticises the delegate for "attempting to attribute a specific, identifiable and measurable rise in global temperatures or other greenhouse impacts from the mine". I do not accept that this criticism is warranted. It may be that if the delegate had been able to detect such a link she could have reached a positive conclusion that an indirect consequence of the proposed action, namely the construction and operation of a coal mine, was likely to be a substantial and significant cause of harm to matters protected under Pt 3. In the absence of such a link, however, the relatively small contribution of the proposed emissions to total global emissions could not be seen as having a significant impact. 124 The circumstances in Anvil Hill, in terms of what was and was not accepted by the delegate in that case, are quite different from the present circumstances, where the Minister has accepted almost all of the contentions put to her about the impacts of climate change, and the impacts of the burning of coal. As we have explained, the Minister's decision here turned on "substantial cause". In Anvil Hill, no connection or cause was accepted. The delegate considered the evidence "uncertain and conjectural", and the link between the proposed action and the impacts "not likely to be identifiable": see Anvil Hill at [26] of the trial decision. The analysis was quite different. Therefore, the somewhat indirect endorsement by Stone J on which the second respondents rely does not take the respondents' argument much further. 125 Senior counsel for the second respondents was correct to submit that the relevant paragraphs in the Minister's reasons ([122], [123] and [124]) explored three different ways of evaluating the effect or impact of the action, only two of which employ a denominator. The assessment in [123] is not dependent on selection of a particular denominator but instead took the appellant's figures on total emissions from the coal produced from the extension of the coal mine, and considered the likely effect of these emissions on global warming. 126 It may be the case that, at base, [123] of the Minister's reasons suffers from the same alleged vice as [122] and [124], in that the Minister chose a particular factual scenario about the rate of global warming and assessed the impact of the burning of coal from the extension of the operation of the mine against that scenario. However, in [123] the Minister made the point, which was not disputed on the appeal by reference to the material before her, that: The department prepared this estimate assuming a one-for-one relationship between temperature and tons of GHG emissions, based on the information EJA provided about findings by the IPCC Working Group I that the relationship between anthropogenic CO2 and global temperature has thus far been approximately linear. 127 In other words, for the reasoning used in [123], the Minister's department had advised her this was a more likely scenario, based on historical information at the time of her decision. This is not reasoning by reliance on a "denominator" at all, and provides a sufficient basis to reject ground 5. 128 In any event, we are not persuaded by the appellant's "denominator" argument in relation to [122] and [124], and we turn to explain why. 129 The second respondents took the approach taken by the primary judge - it was a matter for the Minister to evaluate impact and one available method was to test "substantiality" against present contemporary figures. This, the second respondents submitted gives a "concrete number which the realm of speculation never could" (TS 106). As we have said, a "concrete number" may not be the universe of what is required to assess substantial cause correctly, but ultimately the appellant did not advance a wider or different construction of the phrase in any developed way. 130 There is no doubt that the task of the Minister under s 78(1)(a) involves a predictive exercise. The Minister is required to decide what the new information is "about". She must ask herself whether it is "about" impacts of the action, in the future. 131 Senior counsel for the appellant was correct to submit that this kind of predictive exercise in relation to possible environmental harm (being broadly the subject matter of these EPBC Act provisions) necessarily involves an evaluation of the present state of the environment concerned (to take the example used throughout the appeal, the present state of the Great Barrier Reef) and then an exercise in predicting, on the basis of probative material, the effects of a proposed action (if taken) on the MNES concerned, in this example, the Great Barrier Reef. The legislative scheme allows for differing levels of certainty about that prediction - "has" (the most immediate), "will have" (involving some confidence) and "is likely to have" (being agreed to involve less confidence but to include realistic possibilities). 132 These are evaluative, qualitative tasks, and difficult though they may be, the legislative scheme requires the Minister to reach a state of satisfaction about the factual issue of impact, and in the case of indirect impact, limits the task. The legislative scheme of the EPBC Act deals with a wide and diverse range of MNES, and actions that may affect them, including (as this appeal amply demonstrates) the need to assess complex and changing information. Without clear justification in text, context and purpose, it would be wrong to construe the scheme as requiring the Minister to adopt any particular method or approach, or to constrain the way the Minister must reason. That is especially so where the impacts under consideration are agreed to be caused by global phenomena. 133 Granted, a Minister must reason rationally, and must act reasonably, and make their decision on the basis of probative material. Beyond this, the appellant's submission that the Minister could not evaluate how substantial the contribution of emissions from coal produced by the extension of the mine might be by relying on the latest information describing existing levels of emissions and existing coal consumption cannot be accepted. There is no basis in the legislative scheme to discern a constraint on the way the Minister should reason, nor to discern a constraint on the nature of the information she may select from what is before her, provided as we have explained, it meets the threshold of probative material, and is used in a rational and legally reasonable way in making the decision. 134 As we have observed, a potential alternative construction of "substantial cause" might constrain otherwise available reasoning paths, but no such alternative construction was developed on the appeal. 135 Finally, and mostly as a way of testing the correctness of the conclusions we have already reached, the appellant's submission on this ground did tend to suggest it might be almost impossible for the Minister to reach any (factual) state of satisfaction about impact. The second respondent was correct to point this out, by reference to [38] of the appellant's written reply, which states: The Appellant has (contra PS[49]) repeatedly posited an alternative way of evaluating a dynamic and changing future. It commences with recognising that the global scientific community has performed a power of work to identify what "scenarios" are real possibilities as at now (AS[42]). Those scenarios contain assumptions about variables like continued consumption of seaborne thermal coal. They range from the IEA NZE and similar C1 scenarios to catastrophe (AS[42]-[45]). The Minister could say (e.g.) that the coal from the proposed action would be a significant proportion of total coal still to be burnt in the best scenarios, and decide whether that would make the coal a "substantial cause" of the impacts attendant upon that scenario; at the other extreme, she could say that coal from the proposed action would be a miniscule proportion of total coal still to be burnt in an Armageddon scenario, and then consider the same "substantial cause" issue. She can perform the same task in regard to intermediate points. Answering the question in a few points across the spectrum is likely to lead to a rational basis for disposing of the rest of the points. There are probably other ways of addressing the task, as well. The point, however, is that it is irrational to pretend that the task is not complex, and to reduce it to an arbitrary division exercise based on a fixed historical data point with no basis for thinking that that will be an appropriate divisor in future. Using recent data does not result in rationality (cf. MS[48]) where the task is forward-looking, and the data used is not (AS[63]). (Citations omitted, original italics, original bolding omitted, emphasis added in bold.) 136 This submission should be read with what is in [51] of the appellant's submissions, where the appellant acknowledges the WGIII AR6: vetted 97 scenarios as reaching or exceeding 1.5°C warming during the 21st century with a likelihood of ≤67% and limiting warming to 1.5°C in 2100 with a likelihood >50% (category "C1"), vetted 133 scenarios as exceeding warming of 1.5°C during the 21st century with a likelihood of >67% and limiting warming to 1.5°C in 2100 … (Original italics, emphasis added.) 137 The appellant then refers to what in our respectful opinion was an admission of the impossibility of the task it sought to have the Minister perform, by explaining how it identified one scenario in "order to simplify the point"; namely the "IEA's NZE scenario". This was a scenario that showed a "narrow but achievable path" to net zero emissions by 2050. It is clear why the appellant chose to urge this scenario on the Minister as it would, in proportional terms, likely increase the predicted contribution of the burning of coal from the extension of the mine to global emissions and therefore be more likely to render the burning of that coal a "substantial cause" of the impacts. This was, we accept, a legitimate persuasive exercise for the appellant to use. But on the appeal the appellant seeks to turn it from a legitimate persuasive exercise into a legal error if the Minister did not rely upon the appellant's suggested scenario. That is not an approach that can be accepted. 138 Therefore, in relation to ground 5, our conclusions can be summarised in the following way: (a) The Minister adopted three different strands of reasoning to conclude the burning of coal produced from the extension of operations of the coal mine would not be a "substantial cause" of indirect and adverse impacts on any MNES. They are set out in [122], [123] and [124] of her reasons. (b) The appellant's contentions do not demonstrate any error with the reasoning in [123] of the Minister's reasons, which is orthodox. (c) The appellant has not developed any construction argument that would lead to the conclusion that the correct meaning of "substantial cause" necessarily precludes an approach based on numerical calculations and a factually proportional approach on a global scale, and therefore that the use of numerical calculations alone involves a misunderstanding of the task of evaluating substantial cause. (d) Instead, the appellant's "denominator" argument failed to grapple with the fact that the Minister's statutory task required her to reach conclusions capable of rising to the level of "satisfaction", being conclusions based on more than sheer speculation, or guesswork, even if they involved a predictive exercise. (e) In that context, the appellant has not persuaded us that there is any error in the Minister basing her evaluation on material and information about presently available global emissions and warming levels, that being information which is not entirely speculative, even if it has some assumptions built into it. 139 Ground 5 fails.

CONCLUSION 140 Notwithstanding our conclusions on the grounds of appeal, the arguments on this appeal do underscore the ill-suitedness of the present legislative scheme of the EPBC Act to the assessment of environmental threats such as climate change and global warming and their impacts on MNES in Australia. 141 An observation to similar effect, albeit in a very different context, was made recently by the European Court of Human Rights in Verein KlimaSeniorinnen Schweiz v Switzerland (European Court of Human Rights, Grand Chamber, Application No 53600/20, 9 April 2024) at [415]-[417]: The Court's existing case-law in environmental matters concerns situations involving specific sources from which environmental harm emanates. Accordingly, those exposed to that particular harm can be localised and identified with a reasonable degree of certainty, and the existence of a causal link between an identifiable source of harm and the actual harmful effects on groups of individuals is generally determinable. Furthermore, the measures taken, or omitted, with a view to reducing the impugned harm emanating from a given source, whether at the regulatory level or in terms of implementation, can also be specifically identified. In short, there is a nexus between a source of harm and those affected by the harm, and the requisite mitigation measures may be identifiable and available to be applied at the source of the harm. In the context of climate change, the key characteristics and circumstances are significantly different. First, there is no single or specific source of harm. GHG emissions arise from a multitude of sources. The harm derives from aggregate levels of such emissions. Secondly, CO2 - the primary GHG - is not toxic per se at ordinary concentrations. The emissions produce harmful consequences as a result of a complex chain of effects. These emissions have no regard for national borders. Thirdly, that chain of effects is both complex and more unpredictable in terms of time and place than in the case of other emissions of specific toxic pollutants. Aggregate levels of CO2 give rise to global warming and climate change, which in turn cause incidents or periods of extreme weather; these in turn cause various harmful phenomena such as excessive heatwaves, droughts, excessive rainfall, strong winds and storms, which in turn give rise to disasters such as wildfires, floods, landslides and avalanches. The immediate danger to humans arises from those kinds of consequences in the given climate conditions. In the longer term, some of the consequences risk destroying the basis for human livelihoods and survival in the worst affected areas. Whole populations are, or will be, affected, albeit in varying ways, to varying degrees and with varying severity and imminence of consequences. (Original italics, footnotes omitted.) 142 It was this fundamental distinction that led the ECHR to state at [422]: Because of these fundamental differences, it would be neither adequate nor appropriate to follow an approach consisting in directly transposing the existing environmental case-law to the context of climate change. The Court considers it appropriate to adopt an approach which both acknowledges and takes into account the particularities of climate change and is tailored to addressing its specific characteristics. In the present case, therefore, while drawing some inspiration from the principles set out in the Court's existing case-law, the Court will seek to develop a more appropriate and tailored approach as regards the various Convention issues which may arise in the context of climate change. 143 At present in Australia, the only domestic environmental protection and assessment mechanism available at federal level in relation to MNES is the EPBC Act. Section 527E and its approach to "indirect impact" is especially ill-suited, coming as it does from a very different legislative historical background, located in the "downstream effects" decision of this Court in the Nathan Dam line of authorities: Minister for Environment and Heritage v Queensland Conservation Council Inc [2004] FCAFC 190; 139 FCR 24; see Australian Conservation Foundation Inc v Minister for the Environment [2016] FCA 1042; 251 FCR 308 at [156]; Australian Conservation Foundation Inc v Minister for the Environment and Energy [2017] FCAFC 134; 251 FCR 359 at [39]. 144 There is no comparison between indirect impacts of the kind discussed in the Nathan Dam authorities, and indirect impacts from a global phenomenon such as climate change. This proceeding, and the merits decision-making underlying it, might be said to raise the question whether the legislative scheme is fit for purpose in this respect. 145 Each appeal from the primary judgment must be dismissed. It follows that the appeals in relation to the costs judgment must also be dismissed. There will be orders giving the parties an opportunity to agree on costs orders in respect of the appeals, and to make submissions if costs orders cannot be agreed. If necessary, that issue will be decided on the papers. I certify that the preceding one hundred and forty-five (145) numbered paragraphs are a true copy of the Reasons for Judgment of the Honourable Chief Justice Mortimer and Justice Colvin.

REASONS FOR JUDGMENT HORAN J: 146 I agree with Mortimer CJ and Colvin J that the appeals should be dismissed. I also agree that the disposition of the grounds of appeal turns largely on an analysis of the Minister's reasons for her decisions under s 78 of the EPBC Act. Unless otherwise specified, I adopt the abbreviations used by their Honours in their joint reasons. 147 Section 78 of the EPBC Act confers on the Minister a "limited" power to vary or substitute a new decision under s 75(1), namely, a decision whether an action that is the subject of a proposal referred to the Minister is a controlled action, and which provisions of Pt 3 (if any) are controlling provisions for the action. A "controlled action" is a proposed action the taking of which by the proponent without approval under Pt 9 would be prohibited by one or more provisions of Pt 3. The provision or provisions of Pt 3 are the "controlling provisions" for the proposed action. 148 In each of the present appeals, a delegate of the Minister made a decision under s 75(1) of the EPBC Act that the proposed action is a controlled action, and that the controlling provisions were ss 18 and 18A (significant impact on listed threatened species and communities) and ss 24D and 24E (significant impact of unconventional gas development or large coal mining development on water resources). The proposed actions that had been referred to the Minister under s 68 of the EPBC Act comprised the expansion and extension of the Mount Pleasant coal mine and the Narrabri coal mine, and excluded the continuation of mining operations and associated activities that were authorised by existing approvals (including under the EPBC Act). 149 In a letter from the appellant to the Minister dated 8 July 2022, the appellant requested the Minister to reconsider the decision made under s 75(1) about each of the proposed actions, on the basis of substantial new information about the impacts of the proposed action on matters protected by Pt 3 of the EPBC Act (the reconsideration request). The reconsideration request characterised the purpose of the proposed action as being to "extract substances comprising molecules including carbon, hydrogen, oxygen, nitrogen and sulphur, from where they are presently stored in the Earth … in order to provide - directly or through a supply chain - those substances, in return for payment, to an entity for the purpose of turning them into gases, including carbon dioxide, nitrous oxide and methane, … [which] must end up in the atmosphere". The reconsideration request continued: The substantial new information enclosed with this request and summarised in the enclosed Annexures demonstrates that, by those emissions, the Proposed Project will, or is likely to, have significant physical effects on a number of matters of national environment significance (MNES), including a number not listed as controlling provisions in the controlled action decision. In essence, there is now a global scientific consensus that widespread and catastrophic harm to people, ecosystems, species and the biosphere as a whole is in train as a result of the greenhouse gas emissions created by burning fossil fuels. 150 Accordingly, the appellant submitted to the Minister that she should revoke the delegate's decisions and substitute new decisions that listed all matters of national environmental significance or "MNES" affected by climate change as controlling provisions. The reference to MNES is a shorthand which, although not itself defined in the EPBC Act, is used in the Act to refer to the matters protected by the provisions in Div 1 of Pt 3 (see also the table contained in s 34). 151 The Minister was required by s 78C of the EPBC Act to reconsider each of the decisions made under s 75(1), and either confirm the decision, or revoke the decision in accordance with s 78(1) and substitute a new decision for it. Relevantly, s 78(1)(a) provides that the Minister may revoke a decision made under s 75(1) and substitute a new decision if the Minister is satisfied that the revocation and substitution is warranted by the availability of substantial new information about the impacts that the action has or will have, or is likely to have, on a matter protected by a provision of Pt 3 of the EPBC Act. 152 Accordingly, the questions to be addressed by the Minister in dealing with the appellant's reconsideration requests were whether there was substantial new information about the impacts or likely impacts of the proposed action on MNES and, if so, whether the revocation and substitution of the controlled action decision under s 75(1) was "warranted". It may be assumed for present purposes that the second question would involve a re-exercise of the power under s 75(1) so as to consider afresh whether the proposed action is a controlled action and which provisions of Pt 3 (if any) are controlling provisions for the action, having regard to the impacts of the proposed action on any MNES. 153 In each of the present appeals, the Minister was not satisfied that the information provided by the appellant in the reconsideration request was about the impacts that the proposed action has or will have, or is likely to have, on each of the matters protected by Pt 3 of the EPBC Act. Accordingly, the Minister did not need to consider whether the revocation and substitution of the controlled action decision was "warranted". Nevertheless, the Minister's decision essentially turned on a similar issue concerning whether the proposed action had an impact on any MNES. 154 For such purposes, the steps in the Minister's reasons can be summarised as follows. 155 First, the Minister accepted that the information provided by the appellant was "substantial new information". It was new because much of it was not before the delegate who made the decision under s 75(1). It was substantial because it was of substance and not trivial or inconsequential, and "demonstrate[d] that climate change had various effects" on the relevant MNES: see the Minister's reasons in relation to the Mount Pleasant coal mine project at [97]. 156 Secondly, the Minister made a number of findings about the climate change effects of GHG emissions resulting from the combustion of coal and gas, and the adverse impacts of those climate change effects on MNES. Thus, the Minister found that "the combustion of coal and/or gas on a global scale results in GHG emissions, which increases the effects of climate change, including the regularity, scope and intensity of climate hazards". The Minister also accepted that those effects of climate change "will adversely affect the MNES" named by the appellant in its reconsideration request. Accordingly, the Minister considered that the reconsideration request contained "information which demonstrates in a general sense that climate change from anthropogenic sources of GHG emissions has and/or will have physical effects on protected matters": see Minister's reasons at [104]. 157 In relation to the world heritage values of World Heritage properties, the Minister implicitly accepted that climate change and its flow-on effects "are affecting or will affect" the ecology of the identified declared World Heritage properties in a range of identified ways, and that "climate change is having or will have adverse effects on the flora, fauna and ecosystems of the identified World Heritage properties" which "will, in turn, have adverse effects on the world heritage values of those properties": see Minister's reasons at [99], [100]. The Minister made analogous findings in relation to the effects of climate change on the other relevant MNES: see Minister's reasons at [138], [139] (in relation to National Heritage places), [148], [149] (in relation to Ramsar wetlands), [163] (in relation to listed threatened species and ecological communities), [173] (in relation to listed migratory species), [184] (in relation the environment in Commonwealth marine areas), and [194] (in relation to the Great Barrier Reef Marine Park). 158 It should be noted that these findings were expressed in terms of the adverse effects that climate change "is having or will have" on the relevant MNES: see Minister's reasons at [100]. Similarly, the Minister accepted that the combustion of coal or gas on a global scale "results" in GHG emissions, and that such emissions increase the effects of climate change and, in turn, adversely affect each of the MNES: see Minister's reasons at [104]. These positive findings about the effects of climate change and their impacts on the matters protected by Div 1 of Pt 3 of the EPBC Act were not expressed in terms of likelihood or possibility. The Minister was satisfied that climate change is having or will have those effects and impacts, which will be increased by global GHG emissions resulting from the combustion of coal and gas "on a global scale". As discussed further below, it was permissible for the Minister to express these findings in terms of certainty (the effect or impacts that something has or will have), and there was no need in such circumstances to consider whether climate change is "likely" to have those effects or impacts. 159 Thirdly, the Minister addressed the question "[w]hether the information relates to adverse impacts of the proposed action" on the relevant MNES, within the meaning of "impact" in s 527E of the EPBC Act: see Minister's reasons at [100]-[101]. For such purposes, the Minister found (see Minister's reasons at [105], [140], [150], [164], [174], [185], [195]): (a) "[t]o the extent that the information may be relevant to the physical effects of climate change caused by the proposed action, the request contains information about emissions resulting from the combustion by third parties of the coal to be extracted in the proposed action" (emphasis added); and (b) the physical or flow-on effects of climate change on the relevant MNES are or would be, "if anything, indirect consequences of the proposed action", as they are or would be "events or circumstances that are removed in time and distance from the taking of the action, which is the extraction of coal" (original emphasis). 160 In my view, the Minister was proceeding on the basis that, if and to the extent that the emissions from the combustion of coal to be extracted in the proposed action bring about or contribute to any physical effects of climate change, those effects would be indirect consequences (as opposed to direct consequences) of the proposed action. This is relevant for the purposes of determining whether or not the climate change effects are an "event or circumstance" that is an "impact" of the action within the meaning in s 527E. Importantly, under s 527E(1)(b), for an event or circumstance that is an "indirect consequence" of an action taken by a person, that event or circumstance is an "impact" of the action if "the action is a substantial cause of that event or circumstance" (emphasis added). 161 While the term "indirect consequence" in s 527E is not defined in the EPBC Act, the appellant did not suggest that the Minister was wrong in characterising any climate change effects associated with GHG emissions from the combustion of coal as "indirect consequences" of the proposed actions. It was therefore necessary for the Minister to make a finding whether the proposed actions were a "substantial cause" of the climate change effects on MNES, which the Minister had accepted were the result of the combustion of either or both coal and gas "on a global scale". 162 It may also have been necessary to satisfy s 527E(2), which deals with events or circumstances that are consequences of secondary actions taken by other persons as a consequence of a primary action (here, the extraction and/or sale of coal by the proponent). However, the Minister did not specifically address the requirements of s 527E(2), and it can be assumed that those requirements were capable of being met in the circumstances of the present case (for example, on the basis that the combustion of the coal by ultimate purchasers is facilitated to a major extent by its extraction and sale, and is either within the contemplation of the proponent or is a reasonable foreseeable consequence of its extraction and sale). 163 To summarise, the Minister accepted that the information provided by the appellant in support of each reconsideration request was about the adverse effects of climate change on MNES, including from GHG emissions from the global combustion of coal and gas. However, before the delegate's decision under s 75(1) could be revoked and substituted with a new decision, it was necessary that the information was about the impacts of the proposed action within the meaning of s 78(1)(a). Accordingly, the climate change effects were required to be consequences of the proposed action and, if they were indirect consequences, the proposed action had to be a substantial cause of those climate change effects. 164 The Minister proceeded to examine the nature and degree of the causal link between the proposed action and the accepted climate change effects from GHG emissions arising from the combustion of coal and/or gas on a global scale. The Minister did so by reference to the "substantial cause" requirement contained in s 572E(1)(b), as is apparent from her reasons at [106]: Therefore, I determined that for the information in the request to be about the impacts of the proposed action under section 527E of the EPBC Act, the proposed action must be a substantial cause of the physical effects of climate change on the world heritage values of a declared World Heritage property. 165 There might be some overlap between an inquiry as to whether an event or circumstance is an indirect consequence of a proposed action and an inquiry as to whether a proposed action is a substantial cause of that event or circumstance. However, the Minister did not need to make a separate finding whether or not the climate change effects were indirect consequences of the proposed action. If the proposed action was not a substantial cause of the climate change effects, it would be an academic question whether or not those effects were indirect consequences of the proposed action. Conversely, if the proposed action was a substantial cause of the climate change effects, then it is practically inevitable that the effects would be indirect consequences of the proposed action. 166 In such circumstances, I do not read the Minister's reasons as making any separate finding, conditional or otherwise, that the climate change effects are indirect consequences of the proposed action. In my view, this is what the Minister meant when using the words "if anything" in paragraph [105] of her reasons (that is, the physical effects of climate change "are, if anything, indirect consequences of the proposed action" (original emphasis)). This is also consistent with the first of the two bases of the Minister's finding that the proposed action was not a substantial cause of the climate change effects, which might also be consistent with a conclusion that the climate change effects were not indirect consequences of the proposed action. 167 The Minister determined that each of the proposed actions was "not a substantial cause of the stated physical effects of climate change" on each of the MNES: see Minister's reasons at [107], [141], [151], [165], [175], [186], [196]. This was on two bases (see Minister's reasons at [107], [129]-[130]): first, because the information did not demonstrate that the proposed action will cause any net increase in global GHG emissions and global average temperature (the "no net increase finding"); second, even if that were demonstrated, any contribution from the proposed action to global GHG emissions would be very small (the "very small contribution finding"). 168 The "no net increase finding" was underpinned by the Minister's acceptance of the Department's advice that the likely contribution of the proposed action's emissions towards a net increase in global GHG emissions and average global temperature was "subject to a number of variables" as outlined in the Minister's reasons at [108]-[116]. Without repeating the details of those variables, the tenor of the advice was to emphasise the uncertainty as to whether the proposed actions would themselves lead to an overall increase in the level of global GHG emissions. Thus, the Minister observed that it was "very difficult to estimate the likely net increase in global GHG emissions from the proposed action's emissions", having regard to a range of other factors "including the level of emissions from sources other than the proposed action": Minister's reasons at [113]-[114]. Among other things, the Minister considered that it was "likely that, if the proposed action does not proceed, the prospective buyers will purchase an equivalent amount of coal from a supplier other than the proponent, which would result in an equivalent amount of GHG emissions when combusted, when compared with the amount estimated for the proposed action", and that it was "reasonable to assume that … the market would respond through an increase in supply elsewhere, in circumstances where there is still anticipated demand for the coal from the proposed action": Minister's reasons at [115]-[116]. 169 The "very small contribution finding" proceeded on the basis that the proposed action would result in a net increase in global GHG emissions and global average temperature. The Minister did not accept that such a net increase would be a substantial cause of the accepted physical effects of climate change on MNES from global GHG emissions, by reference to the proportionate contribution of the proposed action to global annual GHG emissions, the increase in global average temperature, and global coal consumption respectively: Minister's reasons at [122]-[125]. For such purposes, although referring to a "net increase", it is clear that the Minister was prepared to treat the entirety of the annual GHG emissions and coal consumption from the proposed action as additional to the global levels. The Minister also accepted the appellant's contentions that there was "an approximately linear relationship between cumulative anthropogenic CO2 emissions and global temperature, such that every tonne of CO2 emissions adds to global warming". However, given that the contribution of the amount of coal to be combusted from proposed action to global GHG emissions and global average temperature was "very small", the Minister concluded that the proposed action would not be a substantial cause of the physical effects of climate change on MNES: Minister's reasons at [125]-[126]. 170 The Minister's central conclusion was repeated in the context of her consideration of the precautionary principle (see s 391 of the EPBC Act) in the following terms (Minister's reasons at [199]): while the information in the request demonstrates that there is a risk of serious or irreversible harm arising from climate change, for the reasons I have explained above, the GHG emissions from the proposed action do not cause 'impacts' on protected matters for the purposes of the EPBC Act. 171 The grounds of appeal are set out in full in the reasons of Mortimer CJ and Colvin J. The first three grounds were addressed by the appellant in a "cascading" manner: (a) First, the appellant submitted that the Minister misdirected herself by having regard to the net increase in global GHG emissions by reference to "hypothetical counterfactual scenarios" in which the proponent did not take the proposed action, rather than conducting a factual inquiry into the consequences of the proposed action on the premise that the action had been or will be taken. This was said to encompass impermissible "substitution reasoning", by which the Minister postulated that the same events or circumstances would be the consequence of different actions if the proposed action did not proceed. (b) Secondly, the appellant submitted that, if it were permissible to have regard to the net increase in GHG emissions from the proposed action, the Minister erred by asking whether the relevant events or circumstances (i.e. the effects of climate change on MNES) are or will be a consequence of such a net increase, rather than whether it was likely that there would be a net increase with such consequences. (c) Thirdly, the appellant submitted that it was irrational and legally unreasonable for the Minister to exclude a real possibility of lower GHG emissions in a future in which the proposed action was not taken because it was "scientifically impossible to reason probabilistically" about future possibilities or scenarios. 172 The question addressed by the Minister was whether the climate change effects of global GHG emissions on each of the relevant MNES were an impact of the proposed action within the meaning of s 527E, and in particular, whether the proposed action was a substantial cause of those climate change effects. This involved a factual inquiry into causation. In conducting such a factual inquiry, at least in relation to events or circumstances that are or may be indirect consequences of a proposed action, it is relevant to consider whether or to what extent those events or circumstances would occur with the proposed action or without the proposed action. Contrary to the appellant's submission, this inquiry may not be limited to a comparison of the situation before the proposed action is taken and the situation after the proposed action is taken, at least in so far as that comparison might embed an assumption that particular events and circumstances occurring after the proposed action must have been caused by that action. The exercise will usually be more straightforward when considering the direct consequences of an action within the meaning of s 527E(1)(a). The identification of indirect consequences of an action, and the question whether such consequences are substantially caused by the action, may be more difficult, particularly in circumstances such as the present case where the future events or circumstances are subject to multiple "variables". 173 In Tarkine National Coalition Inc v Minister for the Environment [2015] FCAFC 89; 233 FCR 254 at [41], Jessup J (with whom Kenny and Middleton JJ agreed) considered whether the Minister was required to take into account certain matters that were said to be consequences of a proposed action when deciding whether to approve the taking of the action under s 136 of the EPBC Act. Referring to a level of reasoning as "a matter of common sense rather than of statutory injunction", Jessup J said: Relevantly to the matter presently under discussion, a consequence is a result or effect. An obligation to take a consequence into account necessarily implies an existing situation, or base line, against which the result or effect occurs. For a fair-skinned person, a consequence of being exposed to the sun over an extended period is sunburn. In such an example, the assumed base line is a person who is not sunburnt. For an urban metropolis, a consequence of staging a hugely popular international event will, absent ameliorative measures, usually be overcrowded public transport. In such an example, the assumed base line is the metropolis with its normal, resident, population. Likewise, for an endangered species, consideration of the consequences of some action would normally proceed from a base line constituted by the existing circumstances of that species, whether they had been brought about by the natural course of events, by previous human actions which had their own "impacts", or a combination of the two. 174 Justice Jessup rejected an argument advanced in that case that the Minister was required to take into account the consequences of the proposal "considered together with any other actions, known or reasonably anticipated, which also had, or were likely to have, consequences for the matter protected by the controlling provision in question": Tarkine National Coalition at [40]. His Honour, at [43], stated: … it was the consequences of the proposal as such - or, at the general level, of the "action" under consideration - that had to be the subject of the Minister's attention under s 136(2)(e). The Minister was under no obligation to take account of the consequences of any other action, present or anticipated. In this sense I agree with counsel for the appellant that use of the metaphor "cumulative impacts" tended to mask what lay at the heart of the appellant's contention, namely, that the Minister was obliged to take account of circumstances which were not consequences of the proposal at all, but which presumptively came about by other actions. In my view, that contention should be rejected. 175 Transposing his Honour's reasoning to the present context, it may be accepted that the Minister was required to identify the direct and indirect consequences of the proposed action, and not to hypothesise what might happen in a future "world" in which the proposed action is not taken. But that did not preclude the Minister from having regard to the "variables" that might be relevant to the events or circumstances resulting from proposed action - here, the enlargement or extension of the existing coal mines. The Minister was engaged in a predictive exercise, in which it was necessary to determine whether and to what extent the accepted impacts of climate change on MNES would be caused by the proposed action. 176 In this regard, there are some similarities between the reasoning adopted by the delegate in Anvil Hill Project Watch Association Inc v Minister for the Environment and Water Resources [2007] FCA 1480; 243 ALR 784 at [25]-[26] (Stone J). Those proceedings raised a question whether the GHG emissions from a proposed coal mine would have or were likely to have a significant impact on MNES. In deciding under s 75(1) of the EPBC Act that the proposed action was not a controlled action, the delegate addressed the "indirect" impacts of the mine by contributing to GHG emissions and the effects of climate change. Justice Stone noted that the delegate had "accepted that greenhouse gases in the Earth's atmosphere are causing changes to that atmosphere and to weather patterns and that these changes might affect matters protected by Pt 3", but had found that any such impacts were "the consequence of human activities on a global scale over a long period of time". The delegate accepted that it was "clear that at a global level, there is a relationship between the amount of carbon dioxide in the atmosphere and warming of the atmosphere". However, the delegate found that "the climate system is complex and the processes linking specific additional greenhouse gas emissions to potential impacts on matters protected by Pt 3 of the EPBC Act are uncertain and conjectural". Accordingly, the delegate concluded (at [26]): In light of this, and in light of the relatively small contribution of the proposed action to the amount and concentration of greenhouse gases in the atmosphere, I found that a possible link between the additional greenhouse gases arising from the proposed action and a measurable or identifiable increase in global atmospheric temperature or other greenhouse impacts is not likely to be identifiable. 177 Before Stone J, the applicant in Anvil Hill relevantly submitted that, as a matter of common sense, "in demonstrating the adverse impact of the greenhouse gas emissions and considering the likelihood of the proposed action having a significant impact, it is sufficient to show that the emissions contribute to climate change and that climate change has, will have or is likely to have a significant impact on matters protected by Pt 3": at [31]. Accordingly, the applicant argued that the delegate had erred by seeking to identity a "measurable or identifiable increase in global atmospheric temperature or other greenhouse impacts". Justice Stone rejected that argument at [40], stating: It may be that if the delegate had been able to detect such a link she could have reached a positive conclusion that an indirect consequence of the proposed action, namely the construction and operation of a coal mine, was likely to be a substantial and significant cause of harm to matters protected under Pt 3. In the absence of such a link, however, the relatively small contribution of the proposed emissions to total global emissions could not be seen as having a significant impact. That is a conclusion that was open to her on the findings she had made. 178 The reasoning of Stone J on this point was not challenged or disturbed on appeal to the Full Court: Anvil Hill Project Watch Association Inc v Minister for the Environment and Water Resources [2008] FCAFC 3; 166 FCR 54. 179 I accept that the decision in Anvil Hill involved a different factual context and addressed a different statutory question of whether the proposed action had a "significant impact" on a matter protected by a provisions of Pt 3 of EPBC Act. However, I do not consider that the decision can be materially distinguished from the present case on its facts. The delegate in Anvil Hill also accepted that there was a clear relationship "at a global level" between GHG emissions (i.e. the amount of carbon dioxide in the atmosphere) and climate change (i.e. warming of the atmosphere), and that such changes may affect matters protected by Pt 3. The uncertainty and conjecture identified by the delegate was in "linking specific additional greenhouse gas emissions to potential impacts on matters protected by Part 3 of the EPBC Act" (emphasis added), that is, in order to identify "a possible link between the additional greenhouse gases arising from the proposed action and a measurable or identifiable increase in global atmospheric temperature or other greenhouse impacts" (emphasis added). That reasoning is at least remotely analogous to the Minister's reasoning in the present case, in the context of addressing whether the proposed action is or will be a substantial cause of the climate change effects resulting from global GHG emissions. 180 Accordingly, while I do not consider that Anvil Hill is determinative of the grounds raised by the appellant in the present case, the decision in that case is consistent with a conclusion that it was open to the Minister to address the factual question of causation by reference to the variables affecting "the likely contribution of the proposed action's emissions towards a net increase in global GHG emissions and global average temperature": Minister's reasons at [108]. Like the delegate in Anvil Hill, the Minister in the present case was also unable to identify a link between the GHG emissions from the proposed action and the accepted effects of climate change resulting from global GHG emissions, finding that other factors (including the level of emissions from other sources) made it "very difficult to estimate the likely net increase in global GHG emissions from the proposed action's emissions and, by extension, the extent of any net increase in global average temperature and the extent to which the world heritage values of declared World Heritage properties will be impacted by the physical effects of climate change": Minister's reasons at [114]. 181 It is true that some of the factors or variables that were taken into account by the Minister were expressed by reference to the situation "if the proposed action does not proceed": see Minister's reasons at [113], [115], [116]. In particular, the Minister had regard to the likelihood that prospective buyers would purchase an equivalent amount of coal from alternative suppliers, having regard to the modelling of demand for thermal coal until 2050. While this might potentially be open to criticism on the basis that it employs "substitution reasoning", it is clear when the paragraphs are read in context that the Minister was exploring whether the proposed action would lead to additional GHG emissions by increasing the demand for coal. It is implicit in the Minister's reasoning that a consequence of the proposed action would be to meet demand that would otherwise be met by alternative supplies of coal, so that the proposed action would not lead to a net increase in global GHG emissions. 182 Accordingly, the Minister was in substance addressing the consequences of the proposed action, including by reference to its effect on and in the light of the identified "variables". That did not involve impermissibly treating as a base line a future world in which the proposed action is not taken, but other equivalent actions are instead taken. Rather, the Minister was conducting a factual inquiry into the consequences of the proposed action or, more particularly, into whether the proposed action is a substantial cause of the accepted effects of climate change from GHG emissions. 183 Another aspect of Ground 1 as particularised in the notice of appeal contends that the Minister failed to consider all of the likely impacts of the proposed action, but rather considered only some of the impacts or considered the impacts "monolithically and without differentiation". I take this to mean that, while the Minister may have accepted that the physical effects of climate change resulting from global GHG emissions had an impact on MNES, she was required to consider the entire "spectrum" of possible adverse effects that are likely in a range of different future scenarios. On this argument, the Minister erred by failing to find that the proposed action will exclude or preclude certain "least warming" scenarios that will no longer be possible if the proposed action is taken. However, in circumstances where the Minister identified the physical effects of climate change on each of the relevant MNES (see Minister's reasons at [14]-[25], [97]-[100], [134]-[139], [145]-[149], [155]-[163], [170]-[173], [179]-[184], [190]-[194]), and accepted that the GHG emissions resulting from the combustion of coal and/or gas on a global scale "increases the effects of climate change, including the regularity, scope and intensity of climate hazards", the question that the Minister was required to address was whether the proposed action would be a substantial cause of those effects (if they could be regarded as indirect consequences of the proposed action). The Minister was not required to answer that question by reference to the likelihood of any one or more particular "scenarios" with or without the proposed action. 184 For those reasons, I consider that Ground 1 of the appeal should be dismissed. 185 The remaining grounds of appeal can be dealt with more briefly. 186 In support of Ground 2, the appellant submits that the Minister erred by addressing the question in terms of whether the proposed action "will" cause a net increase in global GHG emissions, as opposed to whether the proposed action is "likely" to cause such a net increase (in the sense of a real or not remote chance or possibility). This argument also refers to the "spectrum" or range of likely or possible future global warming scenarios, in at least some of which the GHG emissions from the proposed action might be a substantial cause of climate change effects on the relevant MNES. The appellant argues that, by failing to consider whether there is a real or not remote chance of such scenarios, the Minister failed to "modulate" s 527E through the language of "is likely to have" in s 78(1)(a)(ii). The appellant submits that, in order to find that there was no net increase in GHG emissions and no likely impact of the proposed action on matters protected by Pt 3, the Minister would need to have made a finding that there was no real chance or possibility that the proposed action would be a substantial cause of any such impact. 187 In my view, the consideration of likelihood, in the sense of a real or not remote chance, does not enter into the inquiry required under s 527E in determining whether any given event or circumstance is an impact of an action taken by a person. Section 78(1)(a) (along with other provisions including s 75(2) and each of the controlling provisions in Pt 3) is directed to the impacts that an action has or will have, or is likely to have, on a MNES. In respect of any event or circumstance that has been identified as a potential impact which either will happen or is likely to happen, s 572E governs the question whether that event or circumstance is an impact of the proposed action. The event or circumstance must be a consequence of the proposed action and, if an indirect consequence, must be substantially caused by the proposed action. In that way, s 78(1)(a) should be read together with s 527E, rather than (as the appellant submitted) "modulating" s 527E through the phrase "is likely to have" in s 78(1)(a). The question posed by s 527E is one of factual causation, and is not itself one of possibility or likelihood. 188 In the present case, the Minister accepted that the physical effects of climate change from global GHG emissions will have adverse effects on each of the relevant MNES. I agree with Mortimer CJ and Colvin J at [88] that this finding went beyond likelihood to a higher level of certainty. Having made that finding, there was no error in the Minister proceeding to ask whether the proposed action was a substantial cause of the events or circumstances within the meaning of s 527E(1)(b), for the purpose of determining whether the effects of climate change on the MNES were impacts that the proposed action has or will have on matters protected by Pt 3. In other words, because the Minister accepted that global GHG emissions will increase the effects of climate change and that this will in turn have adverse effects on MNES, there was no occasion for the Minister to address whether those effects were impacts that the proposed action "is likely to have". 189 Ground 3 challenges the Minister's use of future "scenarios" in finding that the GHG emissions from the proposed action would not be a substantial cause of the physical effects of climate change on MNES. The appellant submits that it was irrational for the Minister to adopt "probabilistic" reasoning about future global warming scenarios, which are affected by a large number of "complex interconnected variables on a global scale over decades" (see the reasons of the primary judge at [126]). Accordingly, the appellant submits that it was irrational for the Minister not to find that the material before her demonstrated a real chance or possibility of a net increase in global GHG emissions and global average temperature, or a real chance or possibility that the GHG emissions from the proposed action would not be offset or otherwise reduced. In support of that submission before the primary judge, the appellant had relied on an expert report of a climate scientist, Dr Matthew Gidden. Ground 4 of the notice of appeal is directed to the admissibility of Dr Gidden's report for that purpose. 190 As explained above in relation to Ground 2, the Minister's findings on whether the proposed action was a substantial cause of the effects of climate change on MNES did not involve an inquiry into likelihood or possibility. The uncertainties raised by the "complex interconnected variables" were themselves an aspect of why the Minister found that that the proposed action was not a substantial cause of the effects of climate change on each of the relevant MNES, and that the information accompanying the reconsideration request was therefore not about the impacts that the proposed action has or will have, or is likely to have, on the matters protected by Pt 3 of the EPBC Act. This did not involve impermissible "probabilistic" reasoning, and nor did the evidence of Dr Giddens reveal irrationality in the Minister's approach or conclusions in relation to s 527E of the EPBC Act. 191 The Minister expressly took into account a similar submission advanced by the appellant that it was not possible for her rationally to be satisfied that the same or worse impact will necessarily occur in scenarios without the proposed action: see Minister's reasons at [118]-[120]. This submission was also based on the argument that "there is a large range of better feasible scenarios (in terms of lowest temperature increase) which are simply not available if one assumes the existence of [a] coal mine with 10 Mtpa on the seaborne thermal coal market out to 2050" (in the hypothetical example given by the appellant to illustrate the impacts of the proposed action). Conversely, the appellant submitted to the Minister that such "feasible scenarios with lesser increases in the physical effects of climate change on MNES are available in a future without the proposed action". However, the Minister correctly noted that such an analysis "does not address the relevant statutory question, which requires me to consider, in light of new information, whether the proposed action is a substantial cause of the event or circumstance", being the physical effects of climate change on the relevant MNES. 192 In any event, the Minister's conclusion that the proposed actions are not a substantial cause of the climate change effects was based on both the "no net increase finding" and the "very small contribution finding". In so far as the appellant relied on the possibility of "better feasible scenarios" without the proposed action, the extent or degree of contribution of the proposed action to any increase in net global GHG emissions and global average temperature would (on the Minister's reasoning) remain "very small". In some ways, the point sought to be made by the appellant becomes a rhetorical one about the approval of a new or extended coal mine being inconsistent with any future scenarios in which there are no new coal mines from now until 2050. However, that raises policy issues extending beyond the factual inquiry required of the Minister in applying the EPBC Act to each of these particular proposed actions. 193 Finally, Ground 5 of the notice of appeal challenges the "very small contribution finding" as irrational in so far as the calculation of the proportionate contribution of the proposed action was based on "fixed" denominators in relation to global annual emissions and global coal consumption in past years. Contrary to the appellant's submissions, it was open to the Minister to adopt this approach. Accepting that the future was "dynamic", the contemporary figures were nevertheless probative of the size or extent of the proposed action's contribution to the effects of climate change from global GHG emissions. In this regard, I agree with and adopt the reasons of Mortimer CJ and Colvin J at [116]-[138]. 194 I also concur with the concluding observations made by Mortimer CJ and Colvin J at [140]-[144] in relation to the application of the EPBC Act to the assessment of environmental threats to MNES from the effects of climate change at a global level, separately from the treaties and legislation that comprise the international and domestic frameworks for addressing climate change to which the Minister referred in her reasons at [73]-[84]. 195 Accordingly, I consider that Grounds 2 to 5 of the notice of appeal should be dismissed. 196 I agree with the orders proposed by Mortimer CJ and Colvin J. I certify that the preceding fifty one (51) numbered paragraphs are a true copy of the Reasons for Judgment of the Honourable Justice Horan.

Environment Protection and Biodiversity Conservation Act 1999(Cth)ss 12, 15A, 15B, 15C, 16, 17B, 18, 18A, 20, 20A, 23, 24A, 24B, 24C, 24D, 24E, 75, 78(1)(a), 78A, 78C, 82, 527E

MORTIMER CJ AND COLVIN J: 1 The Environment Council of Central Queensland Inc (the appellant) appeals from the primary judgment in Environment Council of Central Queensland Inc v Minister for the Environment and Water (No 2) [2023] FCA 1208 and the costs judgment in Environment Council of Central Queensland Inc v Minister for the Environment and Water (No 3) [2023] FCA 1532. The primary judgment was a single set of reasons in relation to two proceedings, VID 400 of 2023 and VID 401 of 2023, which were dealt with together by the primary judge, as those proceedings framed the same challenge to decisions made by the Minister for Environment and Water under the Environment Protection and Biodiversity Conservation Act 1999 (Cth). The Minister did not accede to the appellant's reconsideration request, and the appellant sought judicial review. 2 For the reasons set out below, both appeals must be dismissed.

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Judgment (18 paragraphs)

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