Most of NOAA’s 1,218 surface temperature stations are situated near heat sources like air conditioners, buildings and asphalt. As you would assume, this drives up the temperatures artificially, making it look like the climate is warmer than it really is.
A study conducted by climate scientist (and “denier” at the same time) Anthony Watts found that there were 410 temperature stations which abided by NOAA’s regulations for station siting, all of which had lower readings than all the other poorly-situated stations. The Daily Caller reported:
“The majority of weather stations used by NOAA to detect climate change temperature signal have been compromised by encroachment of artificial surfaces like concrete, asphalt, and heat sources like air conditioner exhausts,” Anthony Watts, a seasoned meteorologist and lead author of the study, said in a statement Thursday.
These “compromised” weather stations run hotter than stations that are well-sited, and are used by NOAA as a benchmark to make upward adjustments for other weather stations that are part of the agency’s official temperature record.
Watts and his fellow researchers found only 410 “unperturbed” weather stations out of the 1,218 stations used by NOAA to determine U.S. climate trends. These “unperturbed” stations don’t need to be adjusted by NOAA because they had not been moved, had any equipment changes, or change in the time temperatures were observed.
The U.S. isn’t the only place with badly-sited surface temperature stations. These kinds of problems are found around the world. Why would they rely on outdated means of measuring average global temperatures when they’ve got better and more reliable technology like satellite data?
[Climatologist at University of Alabama John] Christy and his colleague Dr. Roy Spencer created the first satellite datasets to observe global temperature trends in 1989, and have global data going back to 1979. Christy’s and Spencer’s satellite measurements, which collect temperature data from the lower atmosphere, show no statistically significant warming since 1994 — a period of 21 years.
“We prefer satellite data because it’s a measurement of the bulk atmosphere,” Christy said, adding this is where global warming should be most apparent. Satellites also don’t need to go through the level of adjustments surface thermometers do.
Why don’t they like satellites? The answer is simple. They don’t yield the conclusion they prefer.