Introductory Remarks by Rhianna Hoover

Welcome, everyone, and thank you for joining. Our panel is “A Climate of Litigation: International Courts and the Evolution of International Environmental Law.” I am Rhianna Hoover. I am an associate at Debevoise & Plimpton in New York and co-chair of ASIL’s International Environmental Law Interest Group. I will be moderating the panel today.

Before introducing our incredible lineup of panelists, I would like to just set the stage a bit on what the current climate of litigation actually is. We have all heard that climate litigation has been on the rise globally in recent years. In preparing for this panel, I actually went to take a look at some of the recent stats on this. I want to give you a sense of the numbers. The climate change litigation database that is run by Columbia University’s Sabin Center now includes well over 2,000 climate cases that have been filed to date. Another key source for monitoring climate-related proceedings, which is the Grantham Research Institute at the London School of Economics, documented 230 new climate cases filed in 2023, and more than 200 cases were filed just in the United States in 2024 and so far in 2025.

What trends are we seeing here? Overall, there has actually been some slowdown in the growth of climate cases just in terms of the pure number of cases brought, but we are seeing a greater diversity in what those cases are about. Two areas I wanted to highlight are a rise in climate washing or greenwashing-type cases and an increase in challenges to the climate policies of governments, and that is happening mostly outside of the United States.

Among these new cases are three advisory opinions that I know many of you will be familiar with already and that we will be talking about today in detail. The first was the request for an advisory opinion on climate change from the International Tribunal for the Law of the Sea (ITLOS), and that was submitted by the Commission of Small Island States. ITLOS issued its opinion on that proceeding in May of last year. We also have the request for an advisory opinion on the Climate Emergency and Human Rights that was submitted to the Inter-American Court of Human Rights by Colombia and Chile. Public hearings in that case concluded in May 2024, and so now we are just awaiting the court’s opinion. And finally, we have the request for an opinion on states’ obligations in respect of climate change from the International Court of Justice (ICJ), and oral proceedings in that case were held in December, and so we are waiting for the court to issue its opinion there as well.

With that, it is my privilege to introduce our panelists today. Joining us by Zoom is Professor Payam Akhavan, who is the Human Rights Chair at Massey College at the University of Toronto, and he served as lead counsel to the Commission of Small Island States in the advisory proceedings before ITLOS, the ICJ, and the Inter-American Court of Human Rights. At the end of the table, we have Nikki Reisch, the Director of the Climate and Energy Program at the Center for International Environmental Law. She previously served as the Legal Director at NYU’s Center for Human Rights and Global Justice and is Clinical Instructor in Human Rights Law and Advocacy at NYU School of Law and CUNY School of Law. Jonathan Patz is an expert in climate and health and previously served as Director of the Global Health Institute at the University of Wisconsin-Madison. He has served as a lead author for the UN Intergovernmental Panel on Climate Change (IPCC), and co-chaired the Health Expert Panel of the U.S. National Assessment on Climate Change. And finally, John Knox is the Henry C. Lauerman Professor of International Law at Wake Forest University, and the former UN Special Rapporteur on Human Rights and the Environment.

The overall rise in climate litigation that I previewed has taken place alongside a growing awareness and recognition that climate change is truly a global existential threat, and that is driven at least in part by where the climate science is now.

Jonathan, you were a lead author for the IPCC, which provides scientific assessments on climate change. Can you tell us a little bit more about the various climate-related topics that the IPCC has considered and what science is now considered settled?

Remarks by Jonathan Patz

The Intergovernmental Panel on Climate Change, the IPCC, first began in 1988. It was combined efforts between the World Meteorological Organization and the United Nations Environment Program, and the first assessment report came out in 1990 that set the stage for the UN Framework Convention on Climate Change.

The IPCC is divided into three main working groups, so three big reports. The first one is on climate science. That is working group one. Working group two is impacts, the so-what of climate change. And then the third group is mitigation, economics, more policy-related.

There are three official rounds of peer review. The sixth assessment report released between 2021 and 2023 received 78,000 review comments from across industry, governments. And the final review is a governmental review. All the governments weigh in and word by word go over the executive summary. Anything that comes out of the IPCC is viewed as fairly conservative.

Where do we stand as far as the status of how confident the IPCC is on what is happening as far as climate change? I am going to quote from the Sixth Assessment: “Warming of the climate system is unequivocal.” It is unequivocal. And since the 1950s, many of the observed changes are unprecedented over decades to millennia. There is no scientific doubt about the warming of the climate. The second thing is that it is unequivocal that human influence has warmed the atmosphere, ocean, and land, and that means that we are responsible. It is mostly from burning fossil fuels, but also deforestation, losing the carbon sinks, and industrial processes. Those are the most important scientific assessments coming out that, and every year it has been more and more certain. The latest report says it is unequivocal about that it is warming and it is about us. We are causing it.

At the Climate Conference of the Parties in 2015 in Paris, the world leaders asked the IPCC, what would it take to prevent disastrous warming to go above 2 degrees centigrade average. Warming above pre-industrial levels would be catastrophic. The world leaders asked for what would it take to stay below 1.5 degrees average warming, and the answer to that was a report that came out in 2018 showing that we would have to cut emissions 45 percent by the end of this decade, by 2030, and get to net zero by 2050 to stabilize. That is the answer to your first question.

Rhianna Hoover

Against that backdrop where we have a consensus on the fact that warming of the climate is happening, that it is due to human influence, and that we know what we need to do to mitigate, let us talk about where the law currently stands. In that specific context of climate change and especially states’ obligations with respect to climate change, is there firmly settled law, and just how settled is it? There are two areas I would like to explore here. The first is environmental law, and the second is human rights law. Nikki, do you want to start with environmental?

Remarks by Nikki Reisch

Sure. And thanks very much for organizing this conversation. I will just say that the Center for International Environmental Law works very squarely at the intersection of human rights and environmental law, and so my answer will bleed into human rights a bit but welcome, obviously, John Knox, to complete and supplement that.

It is worth stating from the outset, as Rhianna’s introduction did, that while climate litigation and climate law per se is a relatively recent and rapidly evolving field, so it might be hard to speak about firmly settled climate law as it is evolving quickly, there is a robust and growing body of precedence from domestic courts, from human rights bodies, from regional courts, notable among them, the European Court of Human Rights being the first international court to firmly hold that climate change is a human rights crisis, triggering and invoking legal obligations under human rights law. And that the failure to act on climate change adequately and in line with science can trigger human rights obligations, and similarly, the first international tribunal to issue an advisory opinion on climate change, the ITLOS, International Tribunal for the Law of the Sea, recognizing that states have obligations under environmental law, the UNCLOS Treaty, to prevent, reduce, and control marine pollution. There are a growing number of courts that have recognized existing obligations under existing international and domestic instruments to address climate change and its consequences, so on a foundational level.

But I want to reinforce a few of the foundational core legal principles that are the content of those obligations, because they are firmly settled based on long-standing international environmental and human rights law, both conventional and customary, that pre-dates the UN climate regime, the climate treaties, and continues to apply alongside them, and indeed was at the heart of much of the discussion around the advisory opinions on climate change in the ICJ and elsewhere.

First, the trans-boundary harm principle is one of the most long-standing customary international law principles that undergirds and applies to climate destructive conduct and indeed underpins that regime. What is firmly established is that states have a duty not to cause or allow activities within their jurisdiction or control to cause significant environmental harm to other states or areas beyond their jurisdiction, including the global commons. That is firmly established and has been recognized by the ICJ, by other courts, and the duty of due diligence not to allow territories to be used for harm applies since the nineteenth century. It has roots in common law in that way, and it has been reflected in numerous environmental agreements, including the UNFCCC. It undergirded their negotiation, as well as many other conventions too numerous to name here, and affirmed by courts.

That duty requires states to take measures to prevent and minimize harm to the environment of other states of the global commons. I stress this because that principle is not unsettled law. The debate right now is about how exactly it applies in the context of climate change, but whether it applies is established. It is very important to underscore that there is no basis for an exception to exempt greenhouse gas emissions that cause climate change or climate harm from this long-standing principle.

As Vanuatu stated before the International Court of Justice in their oral submissions, if an isolated incident of transboundary pollution is unlawful, it is unthinkable that the ultimate form of transboundary pollution is not. That would be like accepting the tragic irony famously noted—and I am quoting here—by Raphael Lemkin, that “murder is unlawful but genocide is not.” That is one key point.

I wanted to just underscore another firmly settled law as the preventive obligation under human rights law. The long-standing duty to prevent, mitigate, and remedy foreseeable violations of human rights that stem from conduct subject to a state’s jurisdiction or control, and that duty encompasses the duty to regulate and the duty to remedy harm, including environmental harm caused by such conduct, and that those are principles that have been affirmed as recently in a recent Inter-American Court of Human Rights decision, La Oroya, among many other places.

The third is to say that a general principle of law, the law of state responsibility, is firmly established and is as applicable in the environmental context as it is under other international obligations, where there is a right, there is a remedy, and that the breach of international obligation incurs state responsibility, namely the duty to cease the wrongful conduct and to repair the resultant harm. That principle is firmly established. It is indeed the bedrock of international relations and of international law, and it admits of no exception for climate destructive conduct.

Fourth and finally, to come back to where we started, the growing body of climate litigation and jurisprudence at the domestic and regional and now increasingly international levels affirms a few settled things: that climate change is justiciable, that it raises legal issues that courts have a key role to play, and that it implicates legal duties and legal rights. The fact that multiple actors contribute to climate change does not render each actor immune to liability or responsibility for their contribution, nor does the fact that multiple actors or entities suffer harm mean no one has standing to demand justice. Rejection of the drop-in-the-bucket argument, rejection of pointing fingers at others in action to justify one state’s or corporation’s own inaction, has happened in a number of cases. This is a high-level answer to the question about what the principles of law are that are firmly settled, but they are foundational to climate justice. I think that is what is being reinforced in countless cases domestically and internationally.

Rhianna Hoover

I completely agree.

John, what about settled principles in the human rights law framework?

Remarks by John Knox

Okay, great. Thank you. To build on what Nikki said, what does a human rights perspective to environmental protection add? One of the most interesting and remarkable developments in both human rights law and environmental law over the last twenty years has been the creation of this field of human rights in the environment.

The environmental principles that Nikki just described are well settled, but they also have real weaknesses. International environmental law focuses on transboundary harm. Generally, states have said whatever you do internally in your own boundaries is really up to you within your discretion, and it focuses on states rather than individuals.

Human rights law provides a way to clarify the stakes. What is at stake is actually the harm to human beings, not just state interests. It provides a well-established body of law that can be applied to environmental issues. That is, human rights law is already well-developed in all kinds of other areas. Finally, and I think most important in some ways, it provides new pathways and forums. The environmental standards that Nikki described are really up to states to decide whether to do anything with or not. It is very difficult for individuals, communities, NGOs to bring cases based on any of those principles to any kind of international body, whereas human rights bodies, for all their weakness, do exist. You can take cases to regional tribunals, you can take them to human rights treaty bodies, and you can take them to special rapporteurs, among others.

Over the last twenty years, these bodies developed a jurisprudence of environmental human rights. This jurisprudence, remarkably, is based on a wide variety of rights, not the human right to a healthy environment, for the most part, because there is no human right to a healthy environment recognized in a global human rights treaty. It is certainly recognized at the regional and national level, and in July of 2022, it was recognized by the General Assembly in a resolution.

But the jurisprudence, whose main principles I am about to describe, was not really based on that. It was based on the greening of other human rights, like rights to life, health, property, private and family life, and so forth. This jurisprudence is essentially consistent and coherent, despite the fact that it arises from all of these different sources and construes all these different rights.

I have written a lot about the relationship of human rights in the environment. I am not going to try and summarize all of those principles here, but the main overarching one is that, yes, environmental harm can and does interfere with the enjoyment of a wide variety of human rights, and that, second, states have responsibilities, they have obligations to protect against that kind of environmental harm.

That very clearly encompasses climate change. As Nikki said, there is no reason why it would not. There is no carve-out for climate change. It would be strange to think that there would be. But increasingly, more recently, in the last ten years or so, international bodies have increasingly applied this environmental human rights jurisprudence to climate change.

Briefly, I think some aspects of that application are pretty clear, easy to understand. For example, it is quite obvious that states have obligations to protect against or to help their own people and people within their jurisdiction adapt to foreseeable and unprotected, un-avoided climate effects. That is the adaptation aspect of climate change. Clearly, states have human rights obligations pretty much independent of how much they have contributed to it.

The Maldives, a small island state in the Indian Ocean, has contributed virtually nothing to the global greenhouse problem, but it still has an obligation to help its people adjust, adapt, to the extent that it can.

Second, states have obligations, when they are taking response measures to climate change, to continue to comply with their human rights. That means it is great if a state wants to build a renewable energy project. It is not great if they decide they want to violate the rights of Indigenous peoples or local communities that are living in the area where they want to build a project. You do not check your human rights at the door just because you are doing something that furthers some kind of climate goal. Again, I would say those are fairly straightforward.

What is not straightforward, what has been more difficult, is the application of human rights norms to mitigation obligations. There are lots of reasons why that is more complicated, which we can maybe get into or maybe they are obvious to you. But I would say even there, the jurisprudence is increasingly clarifying the norms. That is, it is quite clear now that human rights bodies are going to say that states have an obligation to undertake measures to mitigate to the extent of their fair share of their contribution.

Fair share leaves a lot undecided, but I would say the second thing in that aspect that is becoming clear is that human rights bodies will look to see what states themselves have said and what the science has said with respect to both what needs to be done and what a state’s fair share is. Repeatedly, human rights bodies have looked to see, for example, what states have committed to do or what they have said they need to do in order to meet their climate commitments under the Paris Agreement or other bases.

I would say that is increasingly what the body of law, I think almost by consensus, human rights bodies agree on. I have to say, though, a lot of states would agree with everything I have just said, but there are some very important states that would not. There are still states that are resisting the whole idea that human rights has much to say about the environment and certainly much to say about climate change. But maybe we can get into that in a little bit.

Rhianna Hoover

As Nikki mentioned, there is still some debate on how longstanding environmental principles apply in the climate change context. You just mentioned human rights bodies are increasingly clarifying what is required in respect of climate change.

Payam, are any of these issues currently before the ICJ and the Inter-American Court? What are the key unsettled issues that they will hopefully be deciding in their opinions?

Remarks by Payam Akhavan

Thank you for inviting me to this distinguished panel, and I am very sorry that I cannot join you in person, given the current circumstances.

I would say the central point of contention, both in the ITLOS and the ICJ proceedings, is the relationship between the so-called climate change regime consisting of the UNFCCC and the Paris Agreement, on the one hand, and obligations under general international law, on the other. Both before ITLOS and the ICJ, a group of states, in particular, petroleum-exporting countries, argued that the Paris Agreement operates as lex specialis and in effect displaces obligations under general international law. As some of us pointed out, this is an argument of lex specialis without the lex because the Paris Agreement is largely a set of procedural obligations. ITLOS squarely rejected that argument, but the argument was made again before the ICJ. It remains to be seen if the ICJ would adopt a different approach than ITLOS.

Then there was a more sophisticated argument, which did not invoke the principle of lex specialis, and this was largely an argument made by countries in the Global North, which I like to call an “inverted systemic integration argument,” that general obligations of international law should be interpreted in light of the obligations under the Paris Agreement, rather than vice versa. That issue was argued before the ICJ, although in respect of UNCLOS, ITLOS squarely rejected the argument.

Another issue, which I think is quite significant, is whether the obligation to prevent harm, to protect the environment necessarily includes a transitioning away from fossil fuels, which was the agreement at COP28 in Dubai, but which was another point of contention in the ICJ.

In respect of human rights, the main issue, it seems to be, is whether there are extraterritorial obligations insofar as, let us say, climate vulnerable states like Vanuatu, Bangladesh, and what have you, are not able to respect the rights to a healthy environment because of the conduct of other states. And in this respect, the Inter-American Court of Human Rights has adopted a rather expansive approach in its 2017 advisory opinion, recognizing extraterritorial obligations, where by contrast, the European Court of Human Rights has adopted a very narrow approach, and it remains to be seen where the ICJ will land on that issue. And, of course, the human rights issues were not properly before ITLOS, so the ICJ will be the first to pronounce on them.

A couple of other issues, which are somewhat more cutting edge, but quite remarkable, one is the relationship between climate change and the right of self-determination and territorial integrity, insofar as several states, including Tuvalu, Marshall Islands, Kiribati, Maldives, are literally going to disappear as a result of sea-level rise. So one of the more innovative arguments is whether and how the principle of self-determination and territorial integrity is implicated by sea level rise, extreme weather events, and other elements which will, in effect, result in the extinction of some of those states.

But, finally, I think we have a whole set of issues in relation to attribution of liability, where there are a plurality of states that have reached an obligation, the quantification of loss and damages, including the question of historical emissions. The ICJ opinion is likely to address those issues at the abstract level, and they are largely issues that have to be interpreted in light of very specific and detailed factual circumstances. That may have to wait for a contentious proceeding.

Rhianna Hoover

Stay tuned. Nikki, did you have anything to add on this point?

Nikki Reisch

Thanks. No, I think Payam touched on many of the issues I think were in contention before the ICJ.

I would underscore that what we saw before the ICJ was really big polluter states, principally, pursuing an unmitigated attack on the elements required to trigger legal consequences or responsibility for climate change, and they did so through a step-wise fashion, both, as Payam has suggested, narrowing the scope of obligations, trying to reduce the scope of the obligations that apply to the climate treaties only and ignore long-standing customary law, and then trying to interpret and advance an interpretation of those climate treaties as requiring very little at all, just a tick-box exercise, when a more robust interpretation of the content of those treaties would require actually obligations in terms of mitigation, adaptation, and the provision of finance from developed countries to developing countries.

Then we also saw them, when it comes to human rights, not only taking issue with the extraterritorial application of human rights obligations but, in fact, calling into question whether human rights law speaks to climate change at all. And we heard a number of states actually suggesting that because human rights law does not explicitly address climate change or greenhouse gas emissions, that it somehow cannot be applied to them, which of course is nonsense, because human rights law has been interpreted and evolved with the times to respond to threats as they arise, to foreseeable threats of harm, much like UNCLOS does not specifically address greenhouse gas emissions but, of course, was interpreted to construe them as a form of marine pollution that the treaty requires states to prevent reducing control.

Maybe we will get later on in the conversation to some of the alignment where states lined up, because I think the picture that one walked away from the ICJ hearings with was very much that this was not the small states against the big polluters. It was really the big polluters against the rest of the world. There was a remarkable alignment among countries around the core principles of climate justice, the idea that the conduct that has led the world to the brink of climate change violates multiple sources of law, not just provisions of the climate treaties, but long-standing environmental and human rights law, and that that triggers an obligation to cease that harmful conduct and to repair the wrong.

Rhianna Hoover

That is exactly right, and that is actually a great transition into my next question, which was in the ICJ proceedings especially, we saw a pretty remarkable level of agreement among a lot of states on some of the unsettled issues you both touched on, including, for example, the right to a healthy environment, and then we have the big polluter states sort of standing alone.

Payam, can you add a bit on that? How are states orienting themselves around the key issues that will be part of the ICJ opinion?

Payam Akhavan

There is a remarkably broad spectrum of like-minded states, which of course was reflected, inter alia, on the adoption of the UN General Assembly resolution requesting the advisory opinion by consensus, but that was because of the leadership of this very broad range of like-minded states.

But what is remarkable here is the leadership of small island states. The smallest of nations on Earth have risen to the greatest of challenges. Tuvalu has a population of 12,000 people. Vanuatu has a population of 350,000 people. They have played a remarkable leadership role in what I would like to characterize as a planetary politics, and they have had allies in the more significant climate-vulnerable states, ranging from Bangladesh to Kenya to Chile. Then these are the states that are pushing the envelope and trying to—I would not even say adopt an expansive approach toward international law, but really state the obvious that here are these well-established principles of transboundary harm and human rights, and this is how you apply them to the problem of climate change, and it is obviously a catastrophic consequence. The power of their arguments is in the fact that it is blindingly obvious.

As I explained earlier, there were groups of states that were trying to push back and limit the obligations essentially to those procedural obligations contained in the Paris Agreement to transmit progressively ambitious nationally determined contributions, and to say that that is enough, it is not necessary if those pledges are actually sufficient to address the problem of climate change. Among those states, there were the petroleum-exporting states that, as I mentioned earlier, were making a very rigorous argument in favor of lex specialis. They were the countries of the Global North.

But what is significant to note is that the BRICS countries were not supportive of the broad coalition of like-minded states. Brazil, the Russian Federation, China, India, other countries such as Indonesia, were also adopting very narrow approaches, but of course, some of them, such as China and India, would invoke the principle of common but differentiated responsibilities to basically say that this is a problem of the Global North because we are developing countries. In a very general sense, this is how one could divide the different groupings.

The countries that are by far the most responsible for emissions were the ones that were trying to adopt the narrowest position on their obligations under international law.

Rhianna Hoover

Probably unsurprisingly, the leadership group of countries that you mentioned is also those most likely to be heavily impacted and already experiencing a lot of climate impact. I want to shift to the science again for just a minute.

The small island states and LDCs made good use of best available scientific evidence in their submissions in the three advisory proceedings. Jonathan, can you talk about how the IPCC has contribute to that science, specifically on small island states and least developed countries?

Jonathan Patz

As we know, those most vulnerable are the least responsible, and the IPCC covers all sorts of impacts, be it from agriculture, food systems, built environment. My area of expertise is in public health, and so every IPCC assessment has had a health chapter in it. Water resources, all across these sectors is part of the IPCC.

What is really important, especially in the human rights context, is the idea that human health is absolutely core and central to climate change discourse. There are so many pathways through which climate effects our health, be it direct heat impacts, severe storms, droughts, food security, and mental health issues. It is why I have dedicated my career to studying health implications of climate change.

One thing that is new, when climate scientists would be confronted with a severe heat wave or a mega hurricane, typhoon, it was very hard to attribute that single event to climate change, and they have been very hesitant for a long time, until recently, when computer power and other aspects now allow climate scientists to attribute extreme events. Legally, that has brought a whole new era of possibilities.

We now have climate change superfund laws, first in Vermont, then in New York, and California is trying to get something established as well. I think it responds to the fact that with a new weather attribution initiative globally, that you are able to make some sense of these disasters. The fires that were in LA in January, the scientists at UCLA attributed at least 25 percent of the aridity to climate change. There was a paper in the Proceedings of the National Academy of Sciences that showed that in the western United States, climate change has doubled the aridity of fuels and led to an increased risk of forest fires. We have seen a doubling in the area of forest fires due to climate change. This is where the attribution of these severe events is giving some justification for having a legal standing. I am not a lawyer, so I cannot really say that.

But this idea that John’s question about human rights having difficulty in the area of mitigation and fair share, this is where these new U.S. climate change superfund lawsuits and actual state laws now in place and being challenged, in my non-legal opinion, has legs to stand on. Those would be holding oil companies responsible based on the amount of fossil fuels that they have burned, and those are on record. The fact that they have had knowledge of the climate risks since the 1950s, and they have funded climate disinformation campaigns, they have completely adopted the tobacco handbook of disinformation. That is part of the issue, the burning of fossil fuels and being attributable to these weather extremes that are harming people and property.

One last reminder that really health is at the center of this discourse that I think a lot of people do not recognize that this is a direct threat to human health and obviously human rights.

Rhianna Hoover

Some of the scientific advances you mentioned on attribution and getting to a consensus point on the risks and especially the impact to human health, I think that is playing a major role in the international cases as well. I note that the ICJ prior to the oral proceeding in the advisory opinion case, invited IPCC scientists to meet with it in The Hague, which was a departure from its usual procedure.

I will direct this question to Nikki. Do you think that suggests anything about how the court is approaching this proceeding and what issues they are focused on?

Nikki Reisch

More than anything, it is a reflection of the really central and foundational importance of science in defining the scope and content of climate obligations, and also, let us not forget that the core science on the causes and consequences of climate change, the overwhelming evidence that the primary driver of climate change is fossil fuel production and use, that that science is not in dispute. It is one really important observation to say that I know that there were comments about the lack of transparency around this meeting with select scientists and IPCC contributors, but it is important to underscore that in many of the climate cases going on around the world right now, the facts of climate change causes and consequences are not legitimately disputable or contestable, even if we saw before the ICJ quite a number of states try to call some of those facts into contest, including the facts about when states knew of the causes of climate change or our ability to link those consequences to the drivers. But I think that is one key takeaway.

The other is also to underscore that the IPCC reports were themselves among the documents that the UN Secretariat transmitted to the court when the request was made, and so that those are foundational elements of determining the scope and content of climate obligations, just as I think John Knox said originally in his opening remarks, that we are seeing many courts be called upon to interpret what obligations mean in light of the best available science, and that this is critical prerequisite information to be able to make sense of the questions before it, as is the case with many courts. The fossil fuel-related obligations indicated this was in dispute about what they are, but the facts are so clear that if there is an obligation to prevent foreseeable causes of transboundary environmental harm and of human rights harm, both domestically and across borders, that this necessarily follows from that, that there is an obligation to take action to reduce the primary cause of those harms, which is fossil fuels. That should be beyond contest, and we are eager to see that named quite clearly in the forthcoming opinion.

Rhianna Hoover

Shifting topics, let us discuss the actual impact of the advisory opinions once they are issued. We have an opinion from ITLOS. We are waiting very hopefully for the opinions from the ICJ and the Inter-American Court, but we do not know exactly what they will say. John, what is your best guess on how these opinions might advance climate efforts or fail to advance climate efforts?

John Knox

That is a very simple question, Rhianna. First, I can tell you that what I am hearing is that we can hopefully expect the Inter-American Court advisory opinion by June and the ICJ advisory opinion by August. They are going to come out pretty soon.

In terms of what to expect, I think we need to distinguish between what we might reasonably expect from the opinions themselves and what effect those opinions might have on state action, state behavior. I am going to focus on the ICJ, although everything I say would also apply to the Inter-American Court. I just think the Inter-American Court is likely to be more forward leaning.

In terms of from most likely to least likely, let me list some possible things the ICJ advisory opinion might say. I think it is very likely that they are going to affirm that international human rights law does add additional obligations that, in other words, they are going to reject the lex specialis or, as Payam so correctly puts it, the non-lex specialis argument. They are going to say, yes, states have obligations under human rights law. Slightly less likely, but I am still pretty confident that they are going to affirm the major tenets of environmental human rights law as applying to climate change. They are going to say, in other words, that, yes, climate change does interfere with human rights, and that states have obligations to do something about that.

I think it is pretty likely that they are going to say something positive about the right to a healthy environment. Judge Aurescu from Romania asks specifically states to address the content of the right. I am drawing on work by David Boyd, the professor from British Columbia, who is the special rapporteur after I was. He is doing research on this right now, and he told me that something like sixty-five states responded to that by saying that the right to a healthy environment is a binding legal norm already. Not all states agree with that, but I think the court is likely to say something positive about how it is evolving or it is already starting to take on legal normative effect or something.

On extraterritoriality, for the reasons that Payam already said, I think the court is likely going to try to handle that very carefully because the regional courts are in different places on it. I could see them sidestepping the question altogether and just saying some general things about the importance of international cooperation.

Here is where I start to get into areas where I think they are less likely to do this, but I would like to see them. I would like to see a straight up statement that states are, in fact, failing to meet their obligations, just flat out. We need that from the court. It is going to be a major disappointment if the court, after doing all these other things—again, I am focusing on the ICJ—does not say that the major historical emitters have just failed to meet their human rights obligations in this respect. On this one, I have no doubt that the Inter-American Court—well, who knows? But I would expect that the Inter-American Court will say that.

Then, finally, there is the question of remedy and relief. Will the ICJ say something about the consequences of states failing to meet their obligations? Again, here, I think we are in the deeper water where the ICJ is going to be very cautious, but it is going to be difficult for them to avoid it, given everything else that we have been talking about. And here again, I expect the Inter-American Court will be more enthusiastic about going there.

Second, what effect will all this have? I will be honest with you. I do not think it is going to have much effect on governments. I talked with David and Astrid Puentes, who is the current special rapporteur, and Elisa Morgera, who is the special rapporteur on climate change and human rights. I think David and Astrid, or maybe Elisa, are more optimistic than I am. I do not think governments are going to read this opinion, the major emitting governments, and say, “Ah, the scales fall from our eyes. Now we must change our behavior.”

But that does not mean that it is not important, because as we have been discussing and as this whole panel emphasizes, the real action here is in the courts. A strong set of opinions from the ICJ and the Inter-American Court will have a supercharging effect on domestic, regional, and international climate litigation, whereas a negative opinion or an opinion that is not a strong opinion, would have the reverse effect.

I am hopeful that the opinion will not necessarily lead to immediate change in the behavior of states, but I do think it would actually help the processes that we are talking about go more quickly and have more effect, and that would be a major development.

Rhianna Hoover

Payam, anything to add?

Payam Akhavan

I think we need to consider how this jurisprudence will impact domestic law. In Canada, there is currently a case before the Supreme Court where the ITLOS opinion is being invoked, and in common law jurisdictions where customary international is directly applicable, courts may be willing to look at that jurisprudence.

I think another aspect that we should not forget about is the role of these advisory proceedings as a lightning rod for civil society, for like-minded states. There has been an organic process through which civil society and like-minded states have come closer together, and it remains to be seen whether they can now use these advisory opinions in future COP negotiations to state the obvious, that what we have been asking for over the past thirty years, to no avail, is in fact already part of binding international law.

One last point that I also want to make, one of the remarkable aspects of the ICJ hearing were the number of Indigenous peoples who stood up in court in The Hague bubble, which is notorious for its lack of diversity. It is not simply that they were Indigenous people, but they spoke about Indigenous law. And we speak about principles of international law. We look at the different civilizations and legal systems which should be reflected in international law, and Indigenous law has historically been a blind spot. But in the ICJ proceedings, it was remarkable to see how many, in particular, small island states from the Pacific, were speaking about Indigenous law, which in some fashion really is about looking to the Earth as the source of binding norms. And this is natural law, not in a philosophical sense, but literally in the sense of the laws of nature.

I say this because there is a remarkable convergence here between scientific truth and ancient wisdom, and I think that over time, this has the potential to revolutionize our very understanding of international law, because when you marry these abstract obligations with scientific truth, it becomes clear that the consequences of continuing business as usual are inescapable. When we speak about normativity in terms of consequences, Mother Earth is going to exact retribution for our failure to do what is necessary, whether we look at it in terms of scientific evidence or ancient wisdom.

Rhianna Hoover

I am going to ask you another very easy question, John. Do you expect the decisions of the current administration in the United States to slow some of that domestic momentum on climate litigation?

John Knox

I do not know if you have been reading the news lately. Trump is trying to move the United States to an authoritarian state in which he is the authoritarian ruler. On top of that, he is actually probably the most hostile to climate change science of all the authoritarian rulers in the world right now, except for maybe Putin. So that is a bad combination, to put it mildly.

Having said that, there are a couple of other things you can say about it. One is there are changes in the United States; we are reducing our carbon emissions over time due to changes that are independent in some ways of political leadership or not.

Second—and this is cold comfort—I have to say, even when the United States was more clearly a constitutional democracy, the United States was still not very enthusiastic about doing what the ICJ would tell it to do or human rights bodies would tell it to do. In that respect, it is less of a sudden break than you might think. And this is even colder comfort. But if we go into a global depression, that is actually probably going to reduce greenhouse gas emissions. In that sense, Trump is kind of helping the environment without maybe appreciating what he is doing.

Rhianna Hoover

On that happy note, we have just a few minutes. I want to give every panel panelist a chance to end. Any final thoughts, any final takeaways for the folks here? We will start with Nikki and go down the line.

Nikki Reisch

I think that we should not ignore the power of the proceedings to date that have transpired before the International Court of Justice, and we should not just focus on whether the pronouncements in that opinion are going to trigger a change in conduct, because there has been so much gained already from the treasure trove of legal arguments that were put before the court and, importantly, the unmasking that was done, because one of the most important aspects of this process was that it forced certain authorities and governments to show their legal sleights of hand in the light of day and to come clean about the legal arguments that they are often making behind closed negotiation doors. The impacts of this, of having what is the world’s largest climate case, with ninety-six states showing up to recognize the importance of the rule of law, cannot be lost on us in a moment when domestically and internationally, the rule of law is being threatened. That is a testament to that court, but it is also a testament to the power of the Indigenous peoples, the Pacific Island leaders, who changed the fabric of international law practice in that courtroom.

If you were there, you felt that history was being made. There were more diverse advocates before that court than at any time before, more states appearing for the first time because of this issue. That has an indelible impact, and the alliances that were created through that advocacy will have repercussions for years to come, that those regional alliances, including around issues like the recognition of continued statehood and maritime boundaries, will have repercussions. We will see the impacts of this, not only in ongoing climate litigation, as John said, and in legislation and policymaking, but in the negotiations at the climate cops as well.

This is really a treasure trove of jurisprudence and arguments and a demonstration of the power of those on the front lines to shape law and its practice going forward.

Jonathan Patz

As a public health scientist, the case that I have learned the most from is the tobacco wars and the intentional disinformation, what did they know and when did they know it, and the intentional deception of violating the public trust over decades. Tobacco was held out for fifty years, and finally we have laws, and they have paid up. As the fossil fuel industry has completely copied the tobacco handbook and in these state lawsuits and the recent state laws that have been passed, holding fossil fuel accountable under the same model that we finally had tobacco being held accountable, I think that is tremendous. That is something that I have learned that is one way to go, and I would like to see fossil fuels held accountable in the same way tobacco was.

We have had some great gains with Our Children’s Trust, the lawsuit in Montana that won out where in the state constitution, it was guaranteed to have a clean, healthy environment, and the children won that lawsuit. There is some value to that, looking at the health and well-being of children, and to calling out the fossil fuel industries for what they are doing and what they knew they were doing and the damages that have ensued, which are extensive damages.

I will end with one positive note, that when I lecture about the health effects of climate change, I also lecture that getting to a low-carbon economy is potentially the greatest health opportunity of our times. Burning fossil fuels kills five million people a year. Eight million people die from air pollution. 5.1 million of those eight million can be tracked to burning fossil fuels. Designing cities for low-carbon transportation, walking and biking, unbelievable health benefits. Mitigating, having climate action is a huge opportunity, but that is not a legal thing. But I have to leave that, because if we can get to a low-carbon economy, our health will be far better for it.

Rhianna Hoover

Payam, any final thoughts?

Payam Akhavan

I am thinking about the words of Martin Luther King, who said that the moral arc of the universe is long, but it bends toward justice. And I say this because this is really a historical struggle, and it is a historical struggle that asks us to make fundamental changes, not just in global governance, but also in our very way of life. When I have been to the COP meetings, there is the blue section with the heads of state and government, the political elites, the energy industry lobbyists, and then there is the green section for civil society with youth, Indigenous leaders. Here we see a contrast between the past that has brought us to the precipice of disaster and the future leaders who will sooner or later be given the space to lead us in a different direction because the earth will go on with or without us. It is just a question of what price do we have to pay before we make the changes that are required.

John Knox

I feel like I was a little dark in the last thing I said, and so I do not want that to be my last word. I agree with what everyone else said. I do think the ICJ opinion and the other climate litigation showcase sources of optimism for all the reasons that you just heard, and in particular the fact that, again, human rights gives us both language and ways of coming together to use that language to actually push for change. We are seeing that happen all around the world. It is really inspiring. As depressing as some of the things going on in the world right now are, I think these are sparks of hope that we can really look toward for the future that we would like to build.