THE world is on the cusp of a "tipping point" into dangerous climate change, according to new data gathered by scientists measuring methane leaking from the Arctic permafrost and a report presented to the United Nations on Tuesday. "The permafrost carbon feedback is irreversible on human time scales," says the report, Policy Implications of Warming Permafrost. "Overall, these observations indicate that large-scale thawing of permafrost may already have started."
As Arctic ice melts and polar bears see more of their habitat disappear, the animals could lose their famous white coats. Researchers have already witnessed polar bears hybridizing with their brown cousins, but note that it would take thousands of years from them to adapt themselves out of existence.