FACTBOX: What are the U.N. Bangkok climate talks?

(Reuters) - Delegates from up to 190 nations will meet in Bangkok from March 31-April 4 for the first round of U.N. talks on a sweeping new pact to fight climate change.

The Bangkok meeting, totalling about 1,000 delegates led by senior government officials, will be the first formal U.N. negotiations on a U.N. climate treaty since the Kyoto Protocol was negotiated from 1995-97.

* WHY IS A NEW TREATY NEEDED?

-- The U.N. Climate Panel last year blamed human activities, led by burning fossil fuels, for a warming that it said would bring ever more droughts, heatwaves, floods and rising seas.

The panel said that world emissions of greenhouse gases -- now rising fast -- would have to peak by about 2015 and then fall sharply to limit a rise in global temperatures to no more than 2 Celsius (3.6 Fahrenheit) above pre-industrial times.

Spurred by the panel's findings, governments agreed in Bali, Indonesia, in December 2007 to work out a new climate treaty by the end of 2009 to succeed Kyoto. Bangkok will be the first stop on the "Bali roadmap".

* SO WHAT'S WRONG WITH THE KYOTO PROTOCOL?

-- Kyoto obliges 37 developed nations to cut greenhouse gas emissions by an average of at least 5 percent below 1990 levels by 2012. The Bangkok talks will be about widening action to all nations.

Every rich country except the United States has ratified Kyoto. President George W. Bush rejected the pact in 2001, saying it would cost U.S. jobs and unfairly omitted 2012 emissions targets for developing nations such as China and India.