The Potential Bias of Urbanization in Global Temperature Measurements

Simply put if there is an increasing tendency for thermometers to be in close proximity to concrete and asphalt, then they will read systematically higher.

An Example:

This is an official recording station that has never been moved. Instead, urban stuff got built around it:

Can you Guess when the building and parking lot appeared?

In the scientific community this effect (Urban Heat Island) is well known and is generally acknowledged to potentialy contribute a false signal. Therefore, significant effort has been taken to try and correct for this effect, statistically, and subtract it out.

This is very difficult to due in any kind of reliably manner and there is much literature suggesting the current corrections is too small and therefore urbanization is the main cause of the observed "warming". There are other studies that show little or no effect. This is hard to believe.





It is possible to remove that bias if you have a good baseline of urban vs rural data:

The scientific issue, however, is how accurate is this baseline comparision? At the moment there are many different techniques being employed to determine the urbanization bias, but there is no wide spread agreement (yet) on the best methodology for determining the amplitude of this potential bias.

Overall, this is just another example of why temperature data should stop being used as the principal argument for or against global climate change.

Here are two other raw examples that show the potential effects of urbanization on temperature data:

These two airfield sites are 15 miles apart in similar terrain. The Lafayette airfield started to see significant urban build up starting in 2003.