NOAA has over 1200 surface weather observation stations throughout the US. Many have been at the same location for decades. Others may have been moved from time to time. The problem is that too many of them are at locations the do not give accurate surface temperature readings either due to placement near heat generating equipment, concrete buildings or asphalt pavement that wasn't there when the instruments were installed, or defective instruments. This can cause higher readings than are actually present at the location, which of course skews the results as well as the historical record.
It appears that I'm not the only one asking the question.
Anthony Watts, a former TV meteorologist had questions about the accuracy of the readings from many of the weather stations and decided to do some investigating.
To assure accuracy, stations (essentially older thermometers in little four-legged wooden sheds or digital thermometers mounted on poles) should be 100 feet from buildings, not placed on hot concrete, etc. But as photos on Watts' site show, the station in Forest Grove, Ore., stands 10 feet from an air-conditioning exhaust vent. In Roseburg, Ore., it's on a rooftop near an AC unit. In Tahoe, Calif., it's next to a drum where trash is burned.
Watts, who says he's a man of facts and science, isn't jumping to any rash conclusions based on the 40-some weather stations his volunteers have checked so far. But he said Tuesday that what he's finding raises doubts about NOAA's past and current temperature reports.
"I believe we will be able to demonstrate that some of the global warming increase is not from CO2 but from localized changes in the temperature-measurement environment."
If what he's found is also the case in other parts of the world, then the question becomes “How much have the world's temperatures really increased?”
Unless the accuracy and placement of the weather stations can be verified, then any data gathered by them is suspect, which calls into question the dire predictions of many of the “We're-All-Doomed” branch of global warming activists. If the data is suspect or corrupted, than any climate model using that data is likewise suspect or corrupted. The models will be worthless.
Maybe it's time to check the data, or at least the instruments used to collect it.