It is widely being reported that, based on surface-temperature data from the National Oceanographic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA), 2010 was tied for the warmest year on record. What is not so widely reported is that those surface temperature data have been so shamelessly manipulated by climate alarmists that they are entirely unreliable. For a short course in one of the great scientific scandals of all time, go here.
There are a number of things wrong with the data produced by NOAA and NASA, but one of the most basic involves the urban heat island effect. It it commonly understood that cities are warmer than the surrounding countryside; you see that every day in weather reports. Thus, weather stations located in urban areas, as many of them are, tend to show increasing temperatures as urbanization and changing land use make the immediate area of the weather station warmer. One study indicated that even a tiny village of 1,000 people can warm temperatures by up to 3.8 degrees F.
NOAA and NASA used to acknowledge the urban heat island effect and try to correct for it, but that didn’t produce the sort of alarming temperature increases that warmists are looking for. This is how NOAA depicted US temperatures from 1880 to 1999, as posted on NASA’s web site in 1999; click to enlarge:
James Hansen, the head of NASA’s climate unit and one of the worst of the alarmists, said truthfully in 1999:
The U.S. has warmed during the past century, but the warming hardly exceeds year-to-year variability. Indeed, in the U.S. the warmest decade was the 1930s and the warmest year was 1934.
That didn’t get the warmists where they were trying to go, so they have now changed the data by eliminating or drastically reducing the urban heat island effect. NASA now shows very different data for the period 1880-1999 from what it published in 1999. This animated GIF shows how the alarmists changed their own data to create the false impression of a climate crisis:
You probably assume that NOAA and NASA have made their raw data available to independent researchers, along with explanations of the adjustments they have made. But no–those agencies have resisted Freedom of Information Act requests for the original, raw data. One of the most important things the new Congress can do is to force these government agencies to level with the American people and explain the manipulations to which they have been subjecting weather data for years.