On 13 December, the International Union for Conservation of Nature (IUCN) will make history as it addresses the International Court of Justice (ICJ) in a groundbreaking process to determine the legal obligations of countries in respect to climate change and the consequences of failing to act.

The International Court of Justice, the United Nations’ highest judicial body, is beginning landmark hearings on global warming. Here’s a guide.

The top UN court will consider if the world’s largest carbon-emitting nations should pay reparations to smaller climate-vulnerable ones.