Speakers will include German Chancellor Angela Merkel, California Governor Arnold Schwarzenegger, French President Nicolas Sarkozy, and former U.S. vice president Al Gore.
Merkel, a former environment minister who holds a doctorate in physical chemistry, has put climate change at the focus of her country's presidency of the Group of Eight leading industrialized nations, and has been pushing for an international commitment to reduce greenhouse gas emissions by 50% by 2050.
United States President George W. Bush will not attend the summit, but will meet with the organizer, UN Secretary General Ban Ki-moon, after the speeches.
The U.S. leader will host two days of climate change meetings in Washington on Thursday and Friday, which will include India and China.
In her speech, Merkel is expected to urge the UN to start working out a new agreement to replace the Kyoto Protocol, which expires in 2012, ahead of the annual climate treaty conference on the Indonesian island of Bali in December.
A source close to the German government told RIA Novosti Merkel would emphasize the goal of cutting planet-warming emissions by at least half by mid-century, and would call on emerging economies to strive for economic growth without disastrous levels of emissions.
The German chancellor will also hold bilateral meetings with Nicolas Sarkozy, Brazilian President Luiz Inacio Lula da Silva, and former British prime minister Tony Blair, special envoy of the Middle East Quartet.
On Tuesday, Chancellor Merkel will speak at the 62nd Session of UN General Assembly.
