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.
Greg Clark announces £343m government and industry-backed aviation research and development drive, including £58m for pioneering electric flight initiative
Lightweight rockets for satellite launches use renewable bio-propane which company claims reduce CO2 emissions 90 per cent compared to traditional fuels
Key Commons vote awaits, as David Davis highlights concerns over 'common rulebook', including environmental regulations, and business leaders raise alarm over 'no deal' risks
Poll by RenewableUK also finds 61 per cent of Conservative voters would also like to see effective onshore wind development ban lifted