When co-anchor Katie Couric asked Al Gore on the May 24, 2006 Today show “What do you see happening in 15 to 20 years if nothing changes?…Even Manhattan would be in deep water”, he replied: “Yes, in fact the World Trade Center Memorial site would be underwater.”
Earlier, in January 11, 2006 on the same show, Obama Science Czar John Holdren’s prediction was even more terrifying than Gore’s: “There is an even greater threat that scientists can only speculate about. As global temperatures rise, they may cause the massive West Antarctic Ice Sheet to slip more rapidly. Then we’ll be facing a sea-level rise not of one to three feet in a century, but of 10 or 20 feet in a much shorter time. The Supreme Court would be flooded. You could tie your boat to the Washington Monument. Storm surges would make the Capitol unusable.”
But don’t imagine for a moment that this flood of fright would be limited to New York or Washington, D.C. When Tom Brokaw featured NASA Goddard Institute for Space Studies director James Hansen on a two-hour Discovery Channel special titled “Global Warming: What You Need to Know”, those Water World horrors were predicted to be much more widespread than that. Brokaw opened the interview, opining: “About 10 percent of the Earth’s surface is covered by ice, most of it in the polar regions. But if the ice melts, the seas will rise dramatically and the results will be calamitous…If this worst-case scenario should occur, in the coming centuries New York could be abandoned, its famous landmarks lost to the sea.” Whereupon Hansen added: Boston, Philadelphia, Washington, Miami…They would all be under water.”
Much of this alarmism trumpeted to and by the media, arises from reports issued by the UN Intergovernmental Panel on Climate Change (IPCC), based upon two unsupportable claims that are resulting in expenditures of countless billions of dollars for futile programs aimed at combatting climate change. The first attributes global warming-related threats to human greenhouse gas emissions (GHGs), principally carbon dioxide. Key among these are coastal flooding and extreme weather conditions.
The second claim alleges that “…recent decreases in ice mass are correlated with rising air temperatures,” and more specifically that “…the late- 20th century glacier wastage likely has been in response to a post-1970 warming.” Here, the IPCC emphasizes that “Because of the corresponding large areas, the largest contributions to sea level rise came from Alaska, the Arctic and the Asian high mountains. Taken together, the ice sheets in Greenland and Antarctica have very likely been contributing to sea level rise over 1993 to 2003 [italics in the original].”
Unfortunately, that IPCC report has provided the sole basis for draconian regulatory restrictions that the U.S. Environmental Protection Administration is placing upon our nation’s energy production and utilization. A most recent and radical example involves proposed rules to limit GHG emissions from new coal-fired power plants which will most certainly result in loss of a large number of coal facilities. The EPA specifically identifies “greater sea level rise and storm surge” as effects the rule alleges to address.
So how warranted is all that trepidation about a Western Antarctic glacier meltdown? That notion can be traced to November 2001 when a large iceberg separated from that region’s Pine Island Glacier, the continent’s currently fastest moving and largest ice discharger. Some scientists speculated that this event might herald the “beginning of the end” of the West Antarctic Ice Sheet. Other studies during this approximate period indicate otherwise.
Satellite radar measurements of the Pine Island Glacier revealed a retreat rate of about 1.2 kilometers per year between 1992 and 1996. A subsequent mapping study in 2000 using radar altimeter and synthetic aperture radar interferometry revealed a system of tributaries that channel ice from the catchment area into the fast-moving glacier. By comparing the velocity data with information on ice thickness and snow accumulation rates, it was possible to calculate the glacier’s mass balance within an uncertainty of approximately 30%. The results showed that the mass balance of the catchment region was not significantly different from zero.
Still another study of the Pine Island Glacier used satellite altimetry and interferometry to determine the rate of change of thickness of the entire drainage basin between 1992 and 1999. Although it had thinned by up to 1.6 meters per year over that period, the researchers concluded that since glacier dynamics are typically driven by phenomena operating on time scales of hundreds to thousands of years, this was unlikely to have been caused by twentieth century warming. They also said they could “detect no change in the rate of ice thinning across the glacier over [the] 7-year period.”
And what if that 1.6 meter per year thinning continues unabated? The researchers said that, at the present rate, the estimated net contribution to sea-level rise would be 6 mm, or about the width of a paper clip each century.
Also, what about those rapidly melting Greenland glaciers? It seems that they aren’t rushing to the sea nearly as rapidly as breathlessly advertised after all. A study reported ina recent issue of Science magazine titled “21st Century Evolution of Greenland Outlet Glacier Velocities” examined 200 of them across that continent over a period between 2000-2010 using synthetic-aperture radar data collected from satellites and determined that their individual flow rates were complex and varied, both in location and time.
- Page 1 / 2