Anthony Watts, writing at WattsUpWithThat, has just announced the results of a five-year study of climate warming trends in the United States. The study concludes that at least half of the warming trend in the United States is artificial due to improper siting of temperature collectors and subsequent data manipulation, to wit:
The…assessment, for the years 1979 to 2008, yields a trend of +0.155C per decade from the high quality sites, a +0.248 C per decade trend for poorly sited locations, and a trend of +0.309 C per decade after NOAA adjusts the data.
The issue of improperly located weather data collection sites has long been a major bone of contention. Many of the sites were emplaced decades ago in what were then open areas, but growing urban areas and many other heat-generating locations like airports have since surrounded the sites. As a result, temperature sensors often ended up on large concrete expanses like airports, in the middle of cities or, too often, directly in the path of heated air streams from devices like large air conditioning units.
I am sure that this study will be contested ferociously, as was the case with so many critiques of climate science methodologies. But, in my view, the advantage of the Watts et al study is that is it real science – in other words, it is based not on computer models and speculations but on painstaking grunt work: good old-fashioned data collection. As a consequence, the results are reproducible by anyone who wants to do the work.