Rush to Judgment
In January, the National Research Council, the working arm of the National Academy of Sciences, released a report called Reconciling Observations of Global Temperature Change. The most quoted line asserted that the increases in the Earth's surface temperatures over the past century are "undoubtedly real." For Michael Oppenheimer of the Environmental Defense Fund, this ends the global warming debate. "It totally deflates the argument of the so-called skeptics that had used the apparent difference between ground-based and satellite data to argue that we really didn't know whether the world is warming or not," he crowed to The Washington Post. The Post's editorial page concluded that "denials that warming has happened are just plain wrong….Some kind of action to reduce greenhouse gas emissions is urgent."
Case closed? Not quite. John Christy, the NASA climatologist who is the principal investigator for satellite temperature measurements, says that the NRC report–which he helped put together–simply concludes that the surface of the earth has warmed over the last century. This has never been in dispute, even by global-warming skeptics. The report also concluded that surface temperatures in the past two decades have risen at a rate substantially greater than average for the past 100 years. However, Christy notes that the recent rate of increase in surface temperatures is in fact less than it was in the early part of the 20th century, which occurred before humanity had significantly boosted concentrations of "greenhouse gases" like carbon dioxide and methane in the atmosphere.
Oppenheimer's rush to dismiss "the apparent difference between ground-based and satellite data" is also simply wrong. The report plainly acknowledges that those differences are real and substantial. The surface apparently warmed by 0.25 C to 0.4 C since 1979. However, the NRC panel estimates the change in the temperature of the atmosphere as between 0 C to 0.2 C during that time. In other words, the atmosphere may not have warmed at all since 1979. None of the computer models pushed by global-warming promoters produces or explains this difference between surface and atmosphere warming. In fact, the models predict the exact opposite. They say that the atmosphere should warm faster than the surface.
As for the Post's editorial and its call to action: The NRC report nowhere deals with the question of what has caused warming over the last century, and its data do nothing to advance the warming crowd's claims. All it ultimately calls for, in fact, is better monitoring and more research. Who can disagree with that?