Copenhagen will cap two years of negotiations launched in Bali, Indonesia, in December 2007 on a pact to succeed the U.N.'s Kyoto Protocol:
NEW YORK - September 22 - U.N. Secretary-General Ban Ki-moon holds one-day summit on climate change for world leaders at U.N. headquarters. U.S. President Barack Obama and China's President Hu Jintao to be among speakers.
PITTSBURGH, United States - September 24-25 - Leaders of the Group of 20 meet; among issues is to decide ways to finance the fight against climate change.
BANGKOK - September 28-October 9 - Officials from up to 190 countries meet for the fourth session this year of formal negotiations on the Copenhagen deal.
BARCELONA, Spain - November 2-6 - Officials from up to 190 nations hold the fifth and final round of climate talks in 2009 before Copenhagen.
COPENHAGEN - December 7-18 - U.N. talks among 190 nations meant to agree a deal to combat climate change. Environment Ministers are due to attend the final three days, from December 16.