COP3 or COP 3 may refer to: 1997 United Nations Climate Change conference, the third session of the Conference of Parties to the UNFCCC (COP 3) in Kyoto, Japan, where the Kyoto Protocol was adopted Alpha-muurolene synthase, an enzyme Gamma-muurolene synthase, an enzyme Lake Rosseau/Onnalinda Point Water Aerodrome, the Transport Canada LID for the aerodrome in Ontario