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 titled "An area and distance weighted analysis of the impacts of station exposure on the U.S. Historical Climatology Network temperatures and temperature trends" shows that the actual U.S. temperature trend from 1979 to 2008 based on the best sited stations was 0.155 C/decade, which is about half of the NOAA adjusted temperature trend of 0.309 C/decade.
The paper is the result of five years of work by Anthony Watts and the many volunteers and contributors to the SurfaceStations project started in 2007.
The paper is described at Anthony Watts blog 'Watts Up With That' here.
This press release in PDF form: here
The paper in draft form: here
The Figures for the paper: here
A PowerPoint presentation of findings with many additional figures is available online:
Overview of the paper here (PPT)
Methodology – Graphs Presentation here (PPT)
The Berkeley Earth Surface Temperature project (BEST) lead by Dr. Richard Muller used the obsolete method to classify stations and did not find station siting quality to have a significant effect on temperature trends. The BEST project used a distance only rating system from Leroy 1999, to gauge the impact of heat sinks and sources near thermometers.
In October 2011, despite the papers not being accepted, Richard Muller launched a major international publicity blitz announcing the results of the “BEST” project. Dr. Ross McKitrick objected to the publicity blitz since he and other reviewers were prevented from publicly criticizing the project due to confidentiality agreements imposed by the journal publisher.
Dr. Ross McKitrick announced on July 30, 2012 that the Best paper was rejected by the journal. Dr. McKitrick explains why the BEST paper failed to pass peer review here and here.