Global warming update

Get ready for the flood. From SCIENCE, March 24 2006, 311 (5768) there's a report on Ice Sheet Stability. There's a cover news story, an editorial, 2 perspectives and four reports in this issue. I think they mean it, folks. They report that Otto-Bliesner et al. (p. 1751)have "integrated climate model simulations, an ice sheet model, and paleoclimate data to show that the northern latitudes, and particularly the Arctic, were significantly warmer during the Last Interglaciation, when sea level was several meters higher than at present. Further they also estimate that the Greenland Ice Sheet contributed between 2.2 and 3.4 meters of sea level rise in the penultimate deglaciation". Then Overpeck et al. (p. 1747) "compare the model's predictions of warming during the next 130 years to this reconstruction, and conclude that surface temperatures will be as high by the end of this century as they were 130,000 years ago. These conditions would melt enough of the Greenland Ice Sheet to raise sea level by several meters".

Now 'several meters' in Greenland translates as a range of sea levels and local storm and tidal effects depending on location and geomorphology. Suffice to say many coastal communities would be inundated, islands will disappear and king tides will be more royal than usual ;-)

So is it really happening? In one report they say that "determining how quickly Antarctic ice may be disappearing has been difficult to assess. The Gravity Recovery and Climate Experiment (GRACE) satellites were designed to make the needed measurements, and Velicogna and Wahr (p. 1754, published online 23 February) show that the mass of the ice sheet has been decreasing by 152 {+/-} 80 cubic kilometers per year from 2002 to 2005, mostly from losses of the West Antarctic Ice Sheet. Contrary to some projections, ice loss around the margins is proceeding faster than the center of the ice sheet is growing. Glacial earthquakes are triggered by the large and sudden sliding of glaciers and can be observed by global seismic networks." Another researcher found that glacial earthquakes (in Greenland) were found to be "more common in summer and that their annual number has doubled since 2002".

As we drive around in our cars and run our air conditioners and heaters unabated and unconcerned we are changing our planet in ways that we may not yet fully appreciate. So who are you going to blame, and what are you doing about it?