The UN’s principal judicial body, the International Criminal Court (ICJ) ruled that States have an obligation to protect the environment from greenhouse gas (GHG) emissions and act with due diligence and cooperation to fulfill this obligation.  

This includes the obligation under the Paris Agreement on climate change to limit global warming to 1.5°C above pre-industrial levels.  

“Greenhouse gas emissions are unequivocally caused by human activities which are not territorially limited,” judge Yuji Iwasawa said.

The ICJ's landmark ruling lays out the obligation of countries and their governments towards mitigating climate change.

The Court further ruled that if States breach these obligations, they incur legal responsibility and may be required to cease the wrongful conduct, offer guarantees of non-repetition and make full reparation depending on the circumstances. 

The ruling came after the two questions the UN General Assembly asked the judges to consider: what are countries’ obligations under international law to protect the climate from greenhouse gas emissions; and what are the legal consequences for countries that harm the climate system?

The Court used Member States’ commitments to both environmental and human rights treaties to justify this decision.  

Firstly, Member States are parties to a variety of environmental treaties, including ozone layer treaties, the Biodiversity Convention, the Kyoto Protocol, the Paris Agreement and many more, which oblige them to protect the environment for people worldwide and in future generations.  

But, also because “a clean, healthy and sustainable environment is a precondition for the enjoyment of many human rights,” since Member States are parties to numerous human rights treaties, including the Universal Declaration of Human Rights, they are required to guarantee the enjoyment of such rights by addressing climate change.  

The ruling spoke of the impact of fossil fuel and protecting the environment from its emissions. The ICJ ruling said:

Failure of a State to take appropriate action to protect the climate system from [greenhouse gas] emissions – including through fossil fuel production, fossil fuel consumption, the granting of fossil fuel exploration licences or the provision of fossil fuel subsidies – may constitute an internationally wrongful act which is attributable to that State.

UN Secretary-General António Guterres issued a video message welcoming the historic decision, which came a day after he delivered a special address to Member States on the unstoppable global shift to renewable energy. 

"This is a victory for our planet, for climate justice and for the power of young people to make a difference," he said.