The world’s biggest climate case begins at The Hague in the Netherlands today. Oral arguments will be heard by the International Court of Justice (ICJ), which will consider what obligations United Nations member states have under international law to protect the planet from greenhouse gas emissions for future generations.

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

The International Court of Justice (ICJ) in The Hague will hear testimony from nearly 100 countries including Vanuatu, the Pacific island nation that initiated the effort to get a legal opinion. The hearing will attempt to answer key questions as to what countries should do to fight climate change and,