This Sunday, Al Gore will probably win an Academy Award for his global-warming documentary An Inconvenient Truth, a riveting work of science fiction.
The main point of the movie is that, unless we do something very serious, very soon about carbon dioxide emissions, much of Greenland’s 630,000 cubic miles of ice is going to fall into the ocean, raising sea levels over twenty feet by the year 2100.
Where’s the scientific support for this claim? Certainly not in the recent Policymaker’s Summary from the United Nations’ much anticipated compendium on climate change. Under the U.N. Intergovernmental Panel on Climate Change’s medium-range emission scenario for greenhouse gases, a rise in sea level of between 8 and 17 inches is predicted by 2100. Gore’s film exaggerates the rise by about 2,000 percent.
Even 17 inches is likely to be high, because it assumes that the concentration of methane, an important greenhouse gas, is growing rapidly. Atmospheric methane concentration hasn’t changed appreciably for seven years, and Nobel Laureate Sherwood Rowland recently pronounced the IPCC’s methane emissions scenarios as “quite unlikely.”
Nonetheless, the top end of the U.N.’s new projection is about 30-percent lower than it was in its last report in 2001. “The projections include a contribution due to increased ice flow from Greenland and Antarctica for the rates observed since 1993,” according to the IPCC, “but these flow rates could increase or decrease in the future.”
According to satellite data published in Science in November 2005, Greenland was losing about 25 cubic miles of ice per year. Dividing that by 630,000 yields the annual percentage of ice loss, which, when multiplied by 100, shows that Greenland was shedding ice at 0.4 percent per century.
“Was” is the operative word. In early February, Science published another paper showing that the recent acceleration of Greenland’s ice loss from its huge glaciers has suddenly reversed.
Nowhere in the traditionally refereed scientific literature do we find any support for Gore’s hypothesis. Instead, there’s an unrefereed editorial by NASA climate firebrand James E. Hansen, in the journal Climate Change - edited by Steven Schneider, of Stanford University, who said in 1989 that scientists had to choose “the right balance between being effective and honest” about global warming - and a paper in the Proceedings of the National Academy of Sciences that was only reviewed by one person, chosen by the author, again Dr. Hansen.
These are the sources for the notion that we have only ten years to “do” something immediately to prevent an institutionalized tsunami. And given that Gore only conceived of his movie about two years ago, the real clock must be down to eight years!
It would be nice if my colleagues would actually level with politicians about various “solutions” for climate change. The Kyoto Protocol, if fulfilled by every signatory, would reduce global warming by 0.07 degrees Celsius per half-century. That’s too small to measure, because the earth’s temperature varies by more than that from year to year.
The Bingaman-Domenici bill in the Senate does less than Kyoto - i.e., less than nothing - for decades, before mandating larger cuts, which themselves will have only a minor effect out past somewhere around 2075. (Imagine, as a thought experiment, if the Senate of 1925 were to dictate our energy policy for today).
Mendacity on global warming is bipartisan. President Bush proposes that we replace 20 percent of our current gasoline consumption with ethanol over the next decade. But it’s well-known that even if we turned every kernel of American corn into ethanol, it would displace only 12 percent of our annual gasoline consumption. The effect on global warming, like Kyoto, would be too small to measure, though the U.S. would become the first nation in history to burn up its food supply to please a political mob.
And even if we figured out how to process cellulose into ethanol efficiently, only one-third of our greenhouse gas emissions come from transportation. Even the Pollyannish 20-percent displacement of gasoline would only reduce our total emissions by 7-percent below present levels - resulting in emissions about 20-percent higher than Kyoto allows.
And there’s other legislation out there, mandating, variously, emissions reductions of 50, 66, and 80 percent by 2050. How do we get there if we can’t even do Kyoto?
When it comes to global warming, apparently the truth is inconvenient. And it’s not just Gore’s movie that’s fiction. It’s the rhetoric of the Congress and the chief executive, too.