UK's Brown proposes $100 bln annual climate fund

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LONDON, June 26 (Reuters) - Developed countries must contribute collectively to a $100 billion annual fund to fight climate change in developing countries by 2020, UK Prime Minister Gordon Brown said on Friday.

Global talks to agree in December in Denmark a new treaty to fight climate change have struggled to determine how rich countries pay for climate action in poorer nations.

"I propose we take a working figure for this purpose of around $100 billion per annum by 2020," Brown said in London.

"If we are to achieve an agreement in Copenhagen I believe we must move the debate from a stand-off over hypothetical figures."

Britain for the first time gave its support for a Norwegian proposal - being considered by the European Union - to levy a charge on national emissions rights allocated to rich countries under a new climate agreement after 2012.

Brown also said some of the $100 billion fund could be raised from international aviation and shipping, for example from taxing or including these in emissions trading markets.

Funds might also be raised through government-backed bonds to protect forests.

Britain's other targets for the Copenhagen talks included a 2 degees Celsius limit in global warming, achieved by at least a halving of global greenhouse gas emissions by 2050 and an 80 percent cut by developed countries. (Reporting by Gerard Wynn; Editing by XXX)