Arctic Melt Underestimated

According to a new study released by the National Snow and Ice Data Center, the climate change models have significantly underestimated the amount of arctic melting that occurred from 1953 - 2006. The estimates had been based on a melt of 2.5% per decade. The new measurements by NSICD show a 7.8% melt. The impact is that current projections are off by about 30 years.

The figure is from the NSICD press release. It is clear from the figure that the actual amount of melt has been greater than the estimates. Further, starting somewhere in the mid to late 1990s the acceleration moved totally outside the range of the standard deviation (significance level of estimates) of existing models. If you follow the trend of the melt delineated by the red line, will "land" approximately 2050 with zero arctic ice versus the lowest range of the deviation which leaves approximately 2 million square miles of ice in 2050.

We have been told that the world has approximately 10 years to stop and change direction on our contributions to global warming. Using the new data, one would assume that the 10 years has just shifted to six years or less.

There are also significant changes happening with the polar currents. Researchers published an article in the Geophysical Research Letters. According to this study, the salinity and bottom pressure is changing at the Arctic. This "suggest(s) a shift from a clockwise to a counterclockwise pattern prevalent prior to the 1990s."

This is very troublesome news indeed. The ocean circulation is a key ingredient in global climate and weather. The shift being noted in the above research, is not just a slowing of the current , but a reversal of the current. Such a change is likely already having significant effects, but it could throw all the models into the garbage. While ocean currents and climate are complext, certainly the massive melt of the Arctic polar ice is decreasing the salinity, which decreases the specific gravity, which impacts current flow and direction.

We could be past a point of no return, or we could be seeing the beginning of a "tipping point." In other words, we might well overshoot global warming and move right into an ice age.

Meanwhile, the news being trumpeted out of the IPCC climate report is positive. Namely that there is time to change course, and that the change can be implemented without extreme economic impacts. I must say that I am baffled at such "optimism." In light of the ongoing updates that indicate massive changes happening much faster than modeled or predicted, the message seems to be politically massaged. There has been an ongoing debate about whether presenting the realities of the challenge might be make the public seem hopeless.

The presentation by the co-chairs of the IPCC Working Group III gives and array of steps that can be taken to improve the situation. They suggest primarily energy efficiency measure for transportation and home/business, and less polluting energy production. They recommend policy changes, as well, as creating economic incentives (taxes and trading) to move industries and nations towards a smaller carbon footprint.

Earlier articles at UTJ discussing climate collapse and tipping points:

8/27/03 Tipping points - environment and global issues

2/04/04. Environmental collapse - sooner not later

5/27/04 Global Warming on Cats Paws

8/12/05 Global Warming - Have We Hit the "Tipping Point?

3/06/06 Global Warming - A Frightening Thought

Posted by rowan at May 6, 2007 6:08 AM | [eMail this article!] |