U.N. Secretary-General Ban Ki-moon appointed on Tuesday three international figures to recommend a global response to climate change.
The envoys are former Norwegian Prime Minister Gro Harlem Brundtland, former Chilean President Ricardo Lagos and former South Korean Foreign Minister Han Seung-soo.
U.N. spokeswoman Michele Montas said the three would come up with proposals for a critical U.N. conference in Bali, Indonesia, in December and perhaps a high-level conference on the subject during the General Assembly in September.
"Many initiatives are being launched and commitments undertaken by member states, groups of states, civil society and the private sector in this respect," Montas said.
"Very commendable as they are, these actions can only complement and not substitute for the comprehensive international response that is needed," she said.
So far the annual U.N. climate conferences have made little progress in devising new treaty obligations once the Kyoto Protocol on the reduction of carbon emissions expires in 2012.
Brundtland, a physician who was director general of the World Health Organization, headed a U.N. environmental commission that in 1987 developed the concept of sustainable development and led to the Earth Summit.
Lagos, Chile's president from 2000 to 2006, heads a Foundation for Democracy and Development, a group aimed at creating sustainable economic growth and development.
Han, an economics professor, was president of the 56th session of the U.N. General Assembly in 2001-2002 where Ban, the current secretary-general, served as his assistant.