The IPCC states repeatedly that 1) we have reliable temperature records showing how much the planet has warmed in the last century; and 2) computer projections of future climate, while not perfect, simulate the observed behavior of the past so well that they serve as a reliable guide for the future. Therefore, they say, we need to limit carbon dioxide emissions (i.e., energy use) right now, despite the expense and despite the fact that the cost of these restrictions will fall almost all on the United States, gravely harming the world's economic engine while exerting no detectable change on climate in the foreseeable future.
The IPCC claims to have carefully corrected the temperature records for the well-known problem of local ("urban," as opposed to global) warming. But this has always troubled serious scientists, because the way the U.N. checks for artificial warming makes it virtually impossible to detect in recent decades -- the same period in which our cities have undergone the most growth and sprawl.
The surface temperature record shows a warming rate of about 0.17?C (0.31?F) per decade since 1979. However, there are two other records, one from satellites, and one from weather balloons that tell a different story. Neither annual satellite nor balloon trends differ significantly from zero since the start of the satellite record in 1979. These records reflect temperatures in what is called the lower atmosphere, or the region between roughly 5,000 and 30,000 feet.
Four years ago, a distinguished panel of the U.S. National Academy of Sciences concluded that a real disparity exists between the reported surface warming and the temperature trends measured in the atmosphere above. Since then, many investigators have tried to explain the cause of the disparity while others have denied its existence.
So, which record is right, the U.N. surface record showing the larger warming or the other two? There's another record, from seven feet above the ground, derived from balloon data that has recently been released by the National Oceanic and Atmospheric Administration. In two research papers in the July 9 issue of Geophysical Research Letters, two of us (Douglass and Singer) compared it for correspondence with the surface record and the lower atmosphere histories. The odd-record-out turns out to be the U.N.'s hot surface history.
This is a double kill, both on the U.N.'s temperature records and its vaunted climate models. That's because the models generally predict an increased warming rate with height (outside of local polar regions). Neither the satellite nor the balloon records can find it. When this was noted in the first satellite paper published in 1990, some scientists objected that the record, which began in 1979, was too short. Now we have a quarter-century of concurrent balloon and satellite data, both screaming that the UN's climate models have failed, as well as indicating that its surface record is simply too hot.