Global warming threatens extinctions - report

OSLO, April 11 (Reuters) Global warming will become a top cause of extinction from the tropical Andes to South Africa with thousands of species of plants and animals likely to be wiped out in coming decades, a study said today.

''Global warming ranks among the most serious threats to the planet's biodiversity and, under some scenarios, may rival or exceed that due to deforestation,'' according to the study in the journal Conservation Biology.

''This study provides even stronger scientific evidence that global warming will result in catastrophic species loss across the planet,'' said Jay Malcolm, an assistant forestry professor at the University of Toronto and a lead author of the study with scientists in the United States and Australia.

Last month, a UN study said humans were responsible for the worst spate of extinctions since the dinosaurs and urged unprecedented extra efforts to reach a UN target of slowing the rate of losses by 2010.

Scientists disagree about how far global warming is to blame compared with other human threats such as deforestation, pollution and the introduction of alien species to new habitats.

The new study looked at 25 ''hotspots'' -- areas that contain a big concentration of plants and animals -- and projected that 11.6 percent of all species, with a range from 1-43 percent, could be driven to extinction if levels of heat trapping-gases in the atmosphere were to keep rising in the next 100 years.

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