Top court says countries can sue each other for climate damage – this is what to expect

The world’s top court has made it easier for governments to be held legally accountable for failing to tackle the climate crisis – in an a move that experts say will have profound implications for climate-related lawsuits.

In its long-awaited legal opinion – requested by small island nations facing existential threats from sea level rise – the International Court of Justice (ICJ) said states have binding obligations to act on climate change under international law, and failing to do so could constitute a "wrongful act".

In an era of climate science denial and at a time when the United States, one of the world’s biggest polluters, is retreating from climate action under Donald Trump, ICJ judge Yuji Iwasawa called the climate crisis an “urgent and existential threat” and said that greenhouse gas emissions are “unequivocally caused by human activities which are not territorially limited.”

Sir David King, chair of the Climate Crisis Advisory Group (CCAG) and former UK scientific adviser, called it a “moral reckoning”, while former UN human rights chief Mary Robinson called it a “turning point”.

But experts also note that the ICJ’s opinion is not itself legally binding. So what does this actually mean in real terms? Could countries that are suffering the most from the impacts of the climate crisis now sue others – developed nations in the West – that have benefited the most from the historic burning of fossil fuels?