Polar warming 'caused by human activity'

Published on 30/10/2008 21:10

SCIENTISTS claim they have finally proved human behaviour is responsible for warming at the north and south poles.

The researchers hope their work will help to persuade sceptics that mankind is to blame for the melting ice in the Arctic and Antarctic.

Environmental groups have long insisted human activities – such as burning fossil fuels and producing harmful greenhouse gases – are responsible for rising temperatures at the poles but there has been no conclusive proof.

Scientists from the Climate Research Unit at the University of East Anglia studied temperature records from both poles and compared the patterns with models produced by computer simulations.

One model was based on natural temperature changes and the other on those caused by humans.

They discovered that only the model that included human influences was able to reproduce the observed temperature trends.

Dr Peter Stott, head of climate monitoring at the Met Office, who was also involved in the research, said: "In both polar regions the observed warming can only be reproduced in our models by including human influences – natural forces alone are not enough."

Dr Alexey Karpechko, author of the report published in Nature Geoscience, said he hoped the research would help persuade sceptics.

"For me, there's enough evidence without this report, but there are some people who think that we haven't shown enough proof," he said.

As the temperature increases at the poles, ice caps melt, removing a protective layer, so the earth absorbs more sunlight and gets even hotter.

Previous studies have observed rises in Arctic and Antarctic temperatures but have not formally attributed the changes to human influence, partly due to poor observation data.

Last year, the Intergovernmental Panel on Climate Change said there was not enough evidence to be sure humans were responsible for temperature rises at Antarctica.

Dr Richard Dixon, director of WWF Scotland, said the report was "significant", adding: "It's good to get this sort of proof in two of the most crucial regions that are being affected most quickly. It's sometimes quite hard to prove things that are quite obvious."

He compared it to efforts to show that lung cancer was caused by smoking, which took decades to prove.