Posted by
BLOGASSAULT on Monday, February 01, 2010 2:04:09 PM
There was a major station dropout — and an increase in missing data from remaining stations — which occurred suddenly around 1990. Just about the time the global warming issue was being elevated to importance in political and environmental circles.
A clear bias was found towards removing higher elevation, higher latitude, and rural stations — the cooler stations — during this culling process, though that data was not also removed from the base periods from which “averages,” and then anomalies, were computed.
The data also suffers contamination by urbanization and other local factors, such as land-use/land-cover changes and improper siting.
There are also uncertainties in ocean temperatures. This is no small issue, as oceans cover 71% of Earth’s surface.
Surprise, surprise, surpise...