BEIJING, Nov. 26 (Xinhuanet) -- The number of weather-related disasters have quadrupled over the last 20 years, British charity Oxfam said in a report published on Sunday.

There are now as many as 500 weather-related disasters a year from an average of 120 disasters a year in the early 1980s, the organization said.

Meanwhile, the number of people affected by extreme natural disasters has soared by 68 percent, from 174 million a year between 1985 to 1994 to 254 million people a year between 1995 to 2004, Oxfam said.

"This year we have seen floods in South Asia, across the breadth of Africa and Mexico that have affected more than 250 million people," said Oxfam director Barbara Stocking.

"This is no freak year. It follows a pattern of more frequent, more erratic, more unpredictable and more extreme weather events that are affecting more people."

Oxfam said rising greenhouse gas emissions are the major cause for the increase and must be tackled. It urged the UN conference on Climate Change in Bali in December to agree on a mandate to negotiate a global deal to provide assistance to developing countries to cope with the impacts of climate change and reduce green house gas emissions.

"Action is needed now to prepare for more disasters otherwise humanitarian assistance will be overwhelmed and recent advances in human development will go into reverse," Stocking said.

Oxfam said rich countries must move first and fastest since they are most responsible for climate change.

(Agencies)