The UN's top court on Wednesday ruled climate change an "existential problem of planetary proportions" and said countries had a legal duty to act or face consequences.

The island nation of Vanuatu has been the driving force behind efforts to get the International Court of Justice to deliver its first-ever legal opinion on climate change."And you don't have a legal right to do that under international law.

One of the world’s most vulnerable countries to the fallout from climate change has won a landmark legal battle, giving countries new ammunition to pursue some of the planet’s biggest emitters.