International climate law needs teeth

The International Court of Justice last year delivered a legal opinion on climate change with a clarity of purpose not seen since the 2015 Paris Agreement. It left no doubt that states have a legal obligation to prevent significant harm to the climate system and that failure to do so carries legal consequences. My own country, Vanuatu, brought this question to the world and to the court. But we were not alone. We built a coalition of countries spanning every region and gained sustained support from youth movements.