Is It Hotter Now Than Any Time Since 1 B.C.?
In the context of Congress preparing topass controversial “cap-and-trade” legislation in the name of man-made global warming, the Washington Post ran a Juliet Eilperin September 4th article claiming “human-generated greenhouse gas emissions have helped reverse a 2,000-year trend of cooling in the Arctic, prompting warmer average temperatures in the past decade that now rank higher than at any time since 1 B.C.”
Other news outlets ran similar, uncritical treatments of a paper appearing in the September 3, 2009 online version of the journal Science. The lead author was Northern Arizona University professor Darrell S. Kaufman.
Although the Post quotes activists long supporting this position and policies grounded in it, the story is not at all balanced, for the following reasons any of which would have been illuminated by checking with other sources before making these claims:
- The paper is expressly grounded in parts in the Mann et al “Hockey Stick” which was debunked by a report drafted at Congress’ request by committee chaired by former head of the National Academy of Sciences’ Statistics Committee, Edward Wegman;
- The paper itself rhetorically acknowledges the Little Ice Age and, before that, Medieval Climate Optimum (or Medieval Warm Period), both of which were removed from Man et al’s representation of history and the latter of which, ending about 800 years ago, was warmer than today;
- Lead author Kaufmann’s publications include a paper describing over 2000 years when the Alaskan arctic was 2 degrees Celsius (3.6 degrees Fahrenheit) warmer than present;
- The paper ignores a meta-analysis of MacDonald et al (2000) which shows that July temperatures in northern Eurasia were up to 7 degrees Celsius warmer, on and off, for 6,000 years after the end of the ice age.