Environmentalists in Paris and Berlin have been raising the alarm over climate change in the hope of waking politicians up to the threat of global warming.
Nearly 100 heads of state and government are gathered in New York in a bid to reach an agreement over how to proceed.
In December, representatives of 190 nations will meet in Copenhagen to seal a deal on tackling climate change.
United Nations Climate Chief Yvo de Boer said:
“I think we can do a deal in Copenhagen. I think you need to be realistic about what that deal can encompass because time is running out. But I have, at the same time, the feeling that the spotlight, including your spotlight, is focused on climate change in a way that has never happened before, so we have got the politicians in the headlamps and let’s make sure that they deliver.”
US President Barack Obama has been trying to build momentum for a new climate change pact to succeed the Kyoto accord. Kyoto requires mandatory cuts in atmospheric warming gases, but the accord expires at the end of 2012.
The UN summit and the G20 summit at the end of this week are aimed at putting pressure on rich nations to help developing nations install new technologies.
The EU is pushing developed nations to match its pledge to cut emissions by 20 percent on 1990 levels by the year 2020.