The global warming trend has accelerated melting of the Greenland ice sheet and Arctic permafrost, triggering a positive feedback loop which is warming the oceans; which, in turn, will melt more of the Earth's remaining freshwater ice sheets. The resultant warming trend will affect climates in northern mid-latitudes, including North America, as part of a cycle which is unlikely to reverse direction.
These are the main findings of an international team of scientists monitoring several data points for the National Oceanic and Atmospheric Administration's (NOAA) Arctic Report Card. The report card's 2010 update observes "many indications of warming" impacting biology, ocean, and land, and "consistent evidence of warming" in Greenland, summer sea ice, and the Arctic climate. The conclusion of these findings is that a "Return to previous Arctic conditions is unlikely."
While it's true that the earth's concurrent orbital eccentricity and obliquity cycles affect the Arctic's winter temperature, allowing the formation of ice sheets, it is the Arctic's summer temperature that determines the seasonal longevity of the ice sheet. As geophysical sciences professor Dr. David Archer explained in a public lecture Friday night, the increasing amount of CO2 in the atmosphere is staving off the possibility of a trigger event, historically a cold summer precipitated by a drop in CO2, for a next ice age to be realized.
Any attempt to summarize the full canon of climate study would be a disservice both to readers and to the data itself. Readers interested in such a summary would be well informed by reading Dr. Archer's book, The Long Thaw, as a primer for understanding the full import of the NOAA report card update.
Â©2010 Jim Hathaway for Gather.com