Plans by about 150 countries to curb greenhouse gas emissions will slow climate change this century and keep alive a goal of limiting a rise in temperatures to two degrees Celsius (3.6 Fahrenheit), the United Nations said.

A new legal agreement committing the world to curb greenhouse gas emissions is unlikely to be completed before the end of 2011, two years later than originally envisaged, the United Nations' climate chief said.

The UN’s top climate official admitted today that a final global warming treaty will be impossible this year.