The North Pole has been frozen for 100,000 years, but according to scientists, by the end of this century, that won't be true anymore. The top of the world is melting, co-host Scott Pelley ominously opened his February 19 report, later suggesting the melting was irreversible. There may be no stopping it. Arctic warming is accelerating. It's a chain reaction. As snow and ice melt, they reveal dark land and water that absorbs solar heat. That melts more snow and ice and round it goes.
The 60 Minutes co-anchors segment on global warming was spurred by a recent study in the journal Science that pegged faster-than-expected melting of glaciers in southern Greenland to global warming. But that view is not universally held in the scientific community, contrary to the impression Pelley gave viewers with his report, which featured only scientists who blamed climate change for faster glacial melting.
University of Virginia climatologist Pat Michaels  attributes the speed-up in glacier melting to a climate cycle which usually runs over a period of 20-30 years. Temperatures fluctuations around Greenland are part of a phenomenon known as the Atlantic Multi-decadal Oscillation (AMO) that connects with temperature changes further south, in the hurricane formation regions of the tropical Atlantic, wrote Michaels, a senior fellow for environmental studies at the libertarian Cato Institute. The AMO goes through, as its name suggests, multi-decadal swings When the AMO is in its positive (warm) phase, the Atlantic hurricane seasons become active with more and stronger storms; and, apparently, Greenland's glaciers flow faster and dump more ice into the ocean. When the AMO is in its negative (cool) phase, hurricane activity in the Atlantic is suppressed and Greenland's glaciers flow slowly.
Correlating a change in the AMO 11 years ago with a change in glacier melting, Michaels concludes that there is no need to invoke global warming for any of this.
Pelleys report came a few days after one-sided reporting on the same topic  by ABCs World News Tonight and The Washington Post. The Business & Media Institute has extensively tracked media bias on climate change, including a one-side documentary special on Fox News Channel in November 2005 .