Ten senators — seven Democrats, two Republicans, and one independent — have just returned with differing views from a tour of Greenland.
Bernie Sanders (I-VT) talked about the risk of Greenland's ice sheet "being lost." Barbara Mikulski (D-MD) said "melting Greenland ice would cause a 23-foot rise in sea levels worldwide." Bob Corker (R-TN) was more circumspect, saying only that "we're digging in to understand this issue."
Sanders' and Mikulski's statements are reminiscent of Al Gore's movie, An Inconvenient Truth, which contains a montage showing much of Florida disappearing as Greenland melts away. This wacko scenario has never enjoyed much respect from the broad scientific community, and newly published research casts even more doubt on it.
Nonetheless, this climatological legend continues to beget junkets, and serve as the basis for carbon dioxide-reduction bills, currently before congressional committees, just as scary as Gore's flick.
Take Senator Dick Durbin (D-IL)'s "Global Climate Change Security Oversight Act." It cites a United Nations Intergovernmental Panel on Climate Change projection that if, as is commonly projected, the earth's mean surface temperature rises an additional 2-5 degrees F by 2100, the melting of Greenland will cause a sea-level rise of 6.5 to 13 feet.
The IPCC makes no such forecast whatsoever. On page 820 of its spanking-new compendium on climate change, it projects that the melting of Greenland will cause a rise in sea levels of between half an inch and 4.5 inches by 2100. If there were any acceleration of ice loss under a Gore-like scenario, the IPCC says there could be an additional sea-level rise of 8 inches.
Similarly, Senator John Kerry (D-MA) and Rep. Henry Waxman (D-CA), both find that "Risks associated with an additional temperature increase [of 1.8 degrees F] are grave, including the disintegration of the Greenland Ice Sheet."
James Hansen, NASA's chief climate modeler, espoused this scenario in a sworn deposition last year, but when asked whether he could cite a single scientist who agreed with him, he named no one.
And yet that gruesome scene is bullying Congress into passing hasty, ill-conceived policies on climate change.
In fact, the UN Intergovernmental Panel on Climate Change even lowered its estimate of maximum likely sea-level rise for this century. The range used to be from 5 to 27 inches, but in the final version of its most recent climate compendium, the top figure is down to 19 inches. Those estimates assume that carbon dioxide emissions continue to rise at the average rate projected by a large number of future simulations.
The IPCC is very circumspect about its sea-level rise projections. "Models used to date do not include uncertainties in the climate-carbon cycle feedback nor do they include the full effects of changes in ice sheet flow, because a basis in published literature is lacking," it reports. "The projections include a contribution due to increased ice flow from Greenland and Antarctica at the rates observed for 1993 to 2003, but these flow rates could increase or decrease in the future [emphases added].
The most recent research certainly bears out the UN's caution. Writing in Science last month, Eske Willerslev of the University of Copenhagen and several colleagues demonstrated that there was still ice in south-central Greenland during the height of the last interglacial (warm) period, between 116,000 and 130,000 years ago.
During this period, Greenland's temperatures were about 9 degrees F higher than they'll get in the next century. Given that Greenland maintained this temperature for 15,000 years, how can one ever support the notion that less than 2 degrees of warming will cause it to lose most of its ice?
Speaking scientific reserve, Willerslev said his work "suggests a problem with the models" predicting a massive loss of Greenland's ice.
Indeed. But even those models take about 800 years or so for Greenland to lose half of its ice, not a mere century. They assume that human activity will somehow quadruple the amount of carbon dioxide in the air, and keep it at that concentration for a millennium. The actual increase, to date, has been 36%. It's a little cheeky, to say the least, to assume that in the year 2500 we will be burning fossil fuels at a rate several times greater than we are now.
Another corollary to the current Greenland hysteria is that once it loses its ice, it will never get it back. Willerslev and his colleagues hit that one out of the park. They found that in a previous non-glacial period — around 500,000 years or so ago — southern Greenland looked a lot like New England, complete with trees and forests found there today. But the ice obviously came back.
One can only hope that these new findings will compel Congress to cool it on global warming. These are reassuring, rather than inconvenient, truths.