Melting Permafrost Could Make Global Warming Worse

"Global warming might be significantly worse than expected during the next century because the melting of carbon-rich permafrost in Siberia could expel hundreds of billions of tons of extra greenhouse gases into the atmosphere, scientists warn in a new study."

"Experts said they can't be certain how large the impact might be, because they can't accurately estimate how much of the extra greenhouse gases will be absorbed by plants and the oceans."

"The melting of Siberian permafrost that has been frozen for thousands of years could eject about 500 billion tons of carbon dioxide into the atmosphere during the next century, scientists from Russia, Alaska and Florida report in today's issue of Science. By comparison, at present the atmosphere contains about 700 billion tons of greenhouse gases."