Massive Antarctic ice sheet collapses with global warming

A chunk of the Wilkins ice shelf 7 times the size of Manhattan began collapsing almost a month ago. Scientists say the melting of the shelf is another sign of global warming, as temperatures have risen dramatically in Antarctica over the last 50 years. The collapse of the shelf is also a concern because it acts as a buttress for continental ice, which will erode more quickly and lead to rising sea level without the buffer.