Monday, July 19, 2010

Woolly mammoth hunters helped change climate

Ancient hunters who stalked the world's last woolly mammoths likely helped warm the Earth's far northern latitudes thousands of years before humans began burning fossil fuels, according to a study of prehistoric climate change. The demise of the leaf-chomping woolly mammoths contributed to a proliferation of dwarf birch trees in and around the Arctic, darkening a largely barren, reflective landscape and accelerating a rise in temperatures across the polar north, researchers at the Carnegie Institution for Science concluded. The northward march of vegetation affected the climate because of the "albedo effect," in which replacement of white snow and ice with darker land surfaces absorbs more sunlight and creates a self-repeating warming cycle, the study found. If mammoth hunters helped hasten Arctic warming, that would potentially be the first such human impact on climate, preceding that caused by ancient farmers, Chris Field, director of the Carnegie Institution's Department of Global Ecology and a co-author of the study, said on Tuesday. With the advent of agriculture about 7,000 years ago at more southern latitudes, humans are believed to have modified the climate through deforestation and cultivation of new plants, he said...more

Wouldn't you know it...even thousands of years ago, hunters and ag producers were the bad guys. Oh well, at least they were breastfed.

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