Coyote Blog

But maybe not the way you think. 

Via Anthony Watts, Oregon State Climatologist George Taylor sends in a picture of one of the official temperature measuring sites that feed into the databases that are used to track global temperature. 

Here is the official temperature plot from "rural" Forest Grove.  Note the "global warming" that really takes effect around 1984.

Of course, this change might (just call me a holocaust-denying skeptic) be due instead to the fact that the adjacent building installed an air conditioner about 1984 that vented hot air on the thermometer.  If you have never seen one, the vented white box on about 4 foot legs and the small white cylinder on the metal pole next to it are the weather station station. 

Of course, setting the measurement station on a pad of hot asphalt and next to a reflective building are also best practices for getting a thermometer to read high.  The aptly name Mr. Watts has been running a great series on temperature measurement issues in his blog - just keep scrolling.

Update: Andrew Watts found the location on Google maps when I could not, probably because I was looking for a semi-rural area outside of town.  But apparently, this is one of the fastest growing communities in Oregon, and, like with many measurement spots over the last 100 years, a hotter urban environment has enveloped the measurement point.  The location is on the left, and I zoomed straight out on the right, so the location is still in the center.

In 1900, this thermometer was measuring the temperature of miles and miles of pasture.  Today, it is measuring the temperature of acres of asphalt in the middle of a growing city.