Sobering Climate Change Data on Arctic Sea Ice Extent

Marika Holland, of the National Center for Atmospheric Research in Boulder has published a study comparing the actual decline in the extent of Arctic sea ice with the climate change models. There is an undeniable trend of decline in the actual sea ice melting that is even more drastic than the most pessimistic computer models of the global environment. In fact, this latest data shows the melting ice is about 30 years ahead of schedule.

This figure illustrates the extent to which Arctic sea ice is melting faster than projected by computer models. The dotted line represents the average rate of melting indicated by computer models, with the blue area indicating the spread among the different models (shown as plus/minus one standard deviation). The red line shows the actual rate of Arctic ice loss based on observations. The observations have been particularly accurate since 1979 because of new satellite technology. (Illustration by Steve Deyo, ©UCAR, based on research by NSIDC and NCAR. News media terms of use*)

For those of you new to the global warming debate, the extent of polar ice coverage is critical to keeping temperatures low, because the ice is more reflective than the Earth or ocean beneath it. If the polar ice melts faster than expected, the bare earth or liquid water will absorb even more solar radiation and global temperatures will therefore increase faster than expected as well. This, of course, will melt more ice even faster, creating a positive feedback loop that will even further accelerate climate change.