DHAKA: Bangladesh said Tuesday it would need 10 billion dollars from rich countries in the next four years to offset the effects of climate change -- double its original estimate.

The government had previously said it would seek five billion dollars at next month's climate summit in Copenhagen to help it adapt to increased flooding, cyclones and droughts.

But environment minister Hasan Mahmud said that as one of the countries worst affected by climate change, Bangladesh had re-evaluated its adaptation needs.

"We need at least $10 billion in the next four years to adapt to and mitigate the impact of climate change in our country," Mahmud said.

"We'll raise the issue in Copenhagen although the pledging of funds is not the main issue at the climate summit. We are paying the price of carbon emissions of the rich and fast developing countries and they must compensate."

Impoverished Bangladesh, with a population of 144 million, is exceedingly vulnerable to climate change, according to scientists who say the frequency of floods, droughts and cyclones has already increased.

Mahmud said the money would be spent on dredging the country's rivers to keep saline sea waters at bay, building and raising embankments and roads, constructing thousands of shelters and planting trees across the coast.

The Nobel Prize-winning United Nations Inter-governmental Panel on Climate Change (IPCC) says rising sea levels will devour 17 percent of Bangladesh's total land mass by 2050, leaving at least 20 million people homeless.

Mahmud said world leaders must conclude a political framework deal if not a legally binding agreement in Copenhagen so that the poor and climate vulnerable countries can get enough funds to fight global warming.

Last week Bangladeshi Premier Sheikh Hasina told leaders including Gordon Brown of Britain, Kevin Rudd of Australia and United Nations chief Ban Ki-moon in a video conference that the world cannot accept failure at the Copenhagen summit.