Global warming has already created tens of millions of climate refugees, and could go on to drive as many as a billion people from their homes over the next 40 years, says a report from an international migration group.
Refugees often lack the means to travel to rich countries, the report says
A report released on Tuesday by the International Organization for Migration (IOM) says that, within the next four decades, as many as one billion people could be forced from their homes by climate change.
The report also estimates that last year more than 20 million people fled regions due to severe weather events related to climate change, adding that environmental disasters, desertification and water pollution are set to increase in frequency as climate change continues.
"However, much of it is internal or cross border migration, belying some fears that millions of poor people will go to rich countries as a result of climate change," the report says.
The IOM study found that many climate refugees did not have the means to leave their countries, and instead often settled in nearby areas and major cities within their region.
The report cites numerous projections of climate refugee numbers over the next 40 years, ranging from 25 million up to one billion, but notes that lower figures were often based on old data.
African states such as Ethiopia, Mali, Burkina Faso and Senegal have already seen "fairly common" instances of forced environmental migration arising from drought, the report notes, adding that there is a "worrying lack of policies" in rich countries to deal with future waves of climate migrants.
"While acknowledging that the impact of climate change on migration is predominantly internal movement, international migration is nevertheless likely to be increasingly important in the future and will necessitate policy and program responses that are currently lacking," it adds.
The IOM findings were released on the second day of United Nations-backed climate talks in Copenhagen at which it is hoped an international accord can be reached to replace the Kyoto Protocol, which expires in 2012.
Editor: Susan Houlton