Anthony Watts called from the road late Friday afternoon with a verbal update on his latest CSI quest in Northern California. He visited four weather stations and all four had AC Units near the temperature sensor, even the one in the corn field at the Davis Experimental Farm. “All four sites had AC exhaust near the MMTS,” said Anthony. “The one in Santa Rosa at the newspaper had two AC units and two exhaust fans near the MMTS.”
You will find all of Anthony's photos, including Healdsburg Fire Station and Napa State Hospital here.
I thought it might be interesting to compare the temperature records of two station I visited, Colfax and Lake Spaulding (old site) that do not have any AC units nearby with two of stations equipped with companion AC units that were surveyed by Anthony on 6 July 2007.
Santa Rosa (047965
Davis Experimental Farm (042294)
Lake Spaulding (044713)
As you can see the sites with companion AC units showed a warming trend. The two sites without AC units nearby do not have a strong warming trend lines. No idea when the AC units were added to the mix, my guess the warming trends show regional growth and land use changes. Colfax experienced some limited growth and Lake Spaulding has not seen any, and they both do not show any significant warming trend. Looks to me like humans and their air conditioner are causing global warming. Do Air Conditioners = Anthropogenic Global Warming! A more detailed study would be required for any scientific proof, but I found this comparison interesting.
UPDATE: Anthony Watts has posted a look at the Napa State Hospital here. Another AC story, just 9 feet away and directly in line with the MMTS.
UPDATE #2: Anthony has posted some data on the growth in US air conditioning here. He raises some interesting questions that should be investigated.