Thermokarst lakes appear on thawing permafrost soil in northeast Siberia in August 2007. For thousands of years, layers of animal and plant waste have been sealed inside the frozen permafrost. Now climate change is thawing the permafrost and lifting this prehistoric ooze from suspended animation. Russian scientists believe that this organic matter will significantly accelerate global warming. (Photo: Reuters)

Thermokarst lakes appear on thawing permafrost soil in northeast Siberia in August 2007. For thousands of years, layers of animal and plant waste have been sealed inside the frozen permafrost. Now climate change is thawing the permafrost and lifting this prehistoric ooze from suspended animation. Russian scientists believe that this organic matter will significantly accelerate global warming. (Photo: Reuters)

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