By John DeFore
We’re already used to worrying about at least one set of issues when it comes to melting caused by global warming: that water entering oceans from disintegrating arctic ice may cause sea levels to rise worldwide.
Now scientists suggest that another sort of melting could not only be caused by climate change, but could in itself accelerate it. At issue is not polar icecaps but permafrost, the frozen ground found in the far north.
