LONDON (AFP) - More than four times the number of natural disasters are occurring now than did two decades ago, British charity Oxfam said in a study Sunday that largely blamed global warming. "Oxfam... says that rising green house gas emissions are the major cause of weather-related disasters and must be tackled," the organisation said, adding that the world's poorest people were being hit the hardest. The world suffered about 120 natural disasters per year in the early 1980s, which compared with the current figure of about 500 per year, according to the report. "This year we have seen floods...