A new report card from the National Oceanic and Atmospheric Administration gives the polar region close to failing grades. It faults both global warming and recent localized weather shifts.
A NASA satellite found that 430 billion metric tons of ice melted in Greenland from 2010 to 2011, and the melting is accelerating.
What's even more troubling to scientists is that there's been a record darkening of the normally white Arctic land and sea. White snow and ice reflects solar energy, but a melting darker Arctic in the summer absorbs that heat.
