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.

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.

The United Nations’ top court has issued a landmark advisory opinion on climate change. The International Court of Justice’s 15 judges considered for the first time what the court’s president calls “a