New Analysis Concludes that Half of U.S. Warming is Artificial

Climatology - the contentious science. Today, physicist Richard Muller publishes online the results of the Berkeley Earth Surface Temeperature (BEST) re-analysis and finds that the globe has warmed by 2.5 degrees Fahrenheit since the 18th century and about 1.5 degrees since the 1950s. He blames rising CO2.

Near simultaneously, Anthony Watts and his colleagues have published online their new study of U.S. surface temperature trends which concludes:

A reanalysis of U.S. surface station temperatures has been performed using the recently WMO-approved Siting Classification System devised by METEO-France's Michel Leroy. The new siting classification more accurately characterizes the quality of the location in terms of monitoring long-term spatially representative surface temperature trends. The new analysis demonstrates that reported 1979-2008 U.S. temperature trends are spuriously doubled, with 92% of that over-estimation resulting from erroneous NOAA adjustments of well-sited stations upward. The paper is the first to use the updated siting system which addresses USHCN siting issues and data adjustments.

The new improved 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. This issue of station siting quality is expected to be an issue with respect to the monitoring of land surface temperature throughout the Global Historical Climate Network and in the BEST network.

Watts tells me that his new results with regard to adjustments made in U.S. temperature datasets are relevant to the BEST analysis because temperature datasets from around the globe likely suffer from the same problems that lead to spurious trends that suggest strong global warming. In his view, the BEST study's new statistical techniques do not remedy the problem of flawed data.

Watts adds: 

I don't believe the errors associated with NOAA adjustments are deliberate, but simply a case of confirmation bias. They expect to find global warming because a popular theory says they should.

In other news, statistician Ross McKitrick, who debunked Pennsylvania State University* climatologist Michael Mann's notorious "hockeystick" analysis which somehow got rid of the Medieval Warming period, reveals that he was a peer reviewer for the new BEST papers at the Journal of Geophysical Research. His review found serious flaws in those papers and they were turned down by the journal. McKitrick strongly objects to the BEST "publicity blitz" and has released his peer review comments which can be downloaded here.

Note: None of the BEST studies have yet been published in peer reviewed journals.

More to come.

*fixed from wrong attritution to U. Penn.