Urban Heat Islands

I have heard it said as one of the reasons that people dismiss Global Warming as a serious threat, that the temperature measurements are made on the outskirts of expanding towns and cities. These Urban Heat Islands (or UHIs) have grown over time and so the temperature readings have increased as a result. The picture below, stitched together from many night time satellite photos, shows the Earth’s major UHIs (click on the photo for a larger version).

earth at night
The Earth at Night

It is a beautiful and fascinating photo. If people are right, and Climate Change can be attributed to the problem of the measurements being made next to UHIs, then a photo of global temperature anomalies (i.e. warming or cooling) ought to show a similar pattern to that above. In fact the distribution of increasing temperature is quite different.

2005surfacetemp
A picture of Earth’s surface temperature changes.

The climate scientists who predict Global Warming have already taken the UHIs into account. They are scientists and that is the sort of thing they do; look for explanations and adapt the experiment to take the new data into account.