Scientific debate: The hurricanes hitting the US must serve as a "wake-up call" to the world on global warming, the UN's emergency relief co-ordinator has said.
Jan Egeland said he was convinced Katrina and Rita were the result of climate change. "I think it is a wake-up call for everybody in that you have two of the worst hurricanes ever hitting the US within weeks of each other," he said.
Mr Egeland also pointed to hurricanes in the Indian and Pacific oceans and in the Caribbean. "There is no doubt that the climate is changing," he told BBC Radio 4. "We have a tripling of climate-related disasters since the 1960s and 1970s."
Scientists are divided over whether the hurricanes are the result of climate change.