United Nations climate change conferences have grown exponentially in size over the past two decades - from small working sessions into the largest annual conferences currently held under the auspices of the United Nations - and are now among the largest international meetings in the world.

These conferences are the foremost global forums for multilateral discussion of climate change matters, and have an incredibly busy schedule. The conferences, which rotate annually among the five United Nations regional groups, serve as the formal meetings of:

• the Supreme Bodies: Conference of the Parties (COP), Conference of the Parties serving as the meeting of the Parties to the Kyoto Protocol (CMP) and Conference of the Parties serving as the meeting of the Parties to the Paris Agreement (CMA);
• the Subsidiary Bodies: Subsidiary Body for Implementation (SBI) and Subsidiary Body for Scientific and Technological Advice (SBSTA);
• the bodies which have concluded their work: Ad Hoc Working Group on the Durban Platform for Enhanced Action (ADP), Ad Hoc Working Group on the Paris Agreement (APA), Ad Hoc Working Group on Further Commitments for Annex I Parties under the Kyoto Protocol (AWG-KP) and Ad Hoc Working Group on Long-term Cooperative Action under the Convention (AWG-LCA).