International Law is dead, long live International (Climate Change) Law
By Francesco Sindico - Posted on 25 March 2026
Over the past months, and even just in the past few weeks, several world leaders have shared their opinions on the state of the global rules order, another way of framing what one can call “international law”. The Canadian Prime Minister Carney said it is not in transition, but that we are witnessing a rupture of the global rules order. The European Commission leader von der Leyen said the EU has to be realistic and take stock that the global rules order has changed. She said to a group of EU ambassadors:
“We will always defend and uphold the rules-based system that we helped build with our allies, but we can no longer rely on it as the only way to defend our interests or assume its rules will shelter us from the complex threats we face”.
She then slightly U-turned, with a principled commitment to the reform of the United Nations.
The point that comes out from these interventions seems to be that the global rules order is not working and it is “right”, “lawful” to abandon it, rather than try to fix it. So, can we ask ourselves the same question when it comes to climate change? What has international law done for climate change?
Looking at the state of our planet in relation to climate change we could be tempted to say “Not very much…” But, a closer look, and a greater understanding of what international law actually is, and what it is not, reveals at least three things that international law has done for climate change.
First, through the Paris Agreement international law has provided a rules-based framework that shapes how not only States, but also private actors operating within a State, are to operate. Through a cycle of five-year pledges and a multilateral review process, States are moving towards the agreed 1.5 degree goal. Are we moving fast enough? Obviously not. Would we have moved slower without the Paris Agreement? The evidence shows that to be the case. Do you not like the Paris Agreement? Then show me something that can realistically replace it and cater for a global wicked problem like climate change.
Second, international law has provided clarity on the possible illegality of expansion of fossil fuel related activities. Last year the highest judicial body of the United Nations, the International Court of Justice, released its Advisory Opinion on what States have to do to protect the climate system and what consequences they should bear if they do not comply with such obligations. This is international law. Paragraph 427 of the Court’s Opinion maintained that, if a State with high-level capacity and technology were to continue opening new fossil fuel related activities or take measures, such as fossil fuel subsidies, it may be in breach of international law.
Third, and this is where it may end up mattering, international law has inspired communities in the Global South (and North) to seek climate justice in domestic courts. Despite the lack of enforcement of international law, at least in the sense we are used to at a national level, it is starting to filter down to national courts. (This filtering includes the paragraph just mentioned.) Over the past year, a plethora of cases in Germany, Switzerland, the UK, the USA and other countries have the potential of sending positive rippled effects, shock waves, in the fight against climate change. Indonesian farmers have sued a Swiss cement giant for its contribution to climate change and the damages it has had on their livelihoods in Indonesia. Filipino survivors of a deadly typhoon are suing Shell in London. Pakistani civil society is suing the biggest German electricity producer for the damage floods, enhanced by climate change, have caused on their houses and livelihoods. And just last week Client Earth brought a case in the USA against one of the biggest pension funds of the country because of the climate change risks faced by its members through the fund’s investment portfolio. All these cases, whilst domestic in nature, are also in different ways related to international law, to the global rules order, either by inspiration or through litigation strategy.
To those who argue that the international global rules order is dead, I say long live the international global rules order. It is not perfect, but if you do not like it give me an effective alternative. Meanwhile, we are sleepwalking into a world in which powerful countries can decide on a monitor who to attack and annex. This is taking us back to a world of maps and kings where war and the use of force was the law. The international global rules order, imperfect as it may be, was the civilised way out of the law of the jungle. Climate change is an existential global problem. It cannot be solved by one actor, one State alone, it requires cooperation and cooperation requires order, a global rules order. In other words, it requires international law.
Francesco Sindico is a Professor of International Environmental Law at the University of Strathclyde and Founder and Co-Director of the Climate Change Legal Initiative. He delivered these remarks at the Scottish International Development Alliance (SIDA) 2026 Spring Conference in Edinburgh on 10 March 2026, which he attended in his Post 2030 Lead role at the University of Strathclyde Centre for Sustainable Development.