Reuters: Ancient records from icy caves in Siberia show that a small amount of global warming can thaw vast areas of frozen ground and release harmful stores of greenhouse gases, a study showed.
Any melt of permafrost, or permanently frozen soil that covers almost a quarter of the northern hemisphere from Alaska to China, can also destabilize everything from oil and gas pipelines to buildings and roads.
"Global climates only slightly warmer than today are sufficient to thaw significant regions of permafrost,"...