Manmade global warming evident on every continent, polar report finds

Guardian (UK): No corner of the Earth is immune from the effects of global warming, according to a new study that confirms manmade temperature rises in both the Arctic and Antarctic regions. Temperature records over the last century show that warming in the planet's coldest and most remote wildernesses is caused by human emissions of greenhouse gases.

The study, published today in Nature Geoscience, is the first to find the fingerprints of manmade global warming on the Antarctic, where a shortage of data makes it hard to be sure. Last year's report, from the Intergovernmental Panel on Climate Change (IPCC), said human influence could be detected on every continent, except Antarctica. Climate sceptics have exploited this omission to question the science of global warming.

In the new study, Nathan Gillett, then working at the Climatic Research Unit at the University of East Anglia, though now at Environment Canada, compiled, with colleagues, climate data across the Arctic and Antarctic regions since 1900, and compared the patterns with those produced by computer simulations with and without human activity.

They say only the models that included human influences – such as emissions of carbon dioxide and chlorofluorocarbons (CFCs) – were able to reproduce the observed temperature trends.

Gillett said: "The main message is that for the first time we are able to directly attribute warming in both the Arctic and Antarctica to human influence. Melting of ice shelves has implications for sea-level rises."….

Antarctica's Mt Herschel (3335 meters above sea level) from Cape Hallet, with Seabee Hook penguin colony in the foreground. Shot by Andrew Mandemaker, under the Creative Commons Attribution ShareAlike 2.5 License