The official title for the UN's Copenhagen Climate Summit in December 2009 and the proceeding negotiating process.
The term is an acronym for the United Nations Framework Convention on Climate Change Conference of the Parties (COP), which oversees international climate change negotiations.
The series of 15 COP meetings have run since 1995 and have shaped international treaties to combat climate change. COP 3 saw the Kyoto deal agreed in 1997, while subsequent meetings moved towards agreeing a successor to the Kyoto deal which it was hoped would be finalised at COP 15 in Copenhagen.
Copenhagen ended only in a non-binding deal known as the Copenhagen Accord, which included few detailed commitments and failed to secure the backing of some countries.
Attention has turned to the scheduled COP 16 meeting in Mexico in December 2010 when it is hoped a binding treaty can be agreed.
A round up of green business news from around the world
'We have to repurpose capitalism': Meet the radical green business group inspired by XR and the climate strikes
Business Declares initiative launches in support of Global Strike, as millions around the world take to streets to demand climate action
Wera Hobhouse sets out the Lib Dem's net zero plans and warns any politician saying they can deliver the same goal by 2030 is 'fibbing'
The past week provides an avalanche of evidence that the climate strike movement is working