Just last month, these were the claims:
We’re screwed: 11,000 years’ worth of climate data prove it. It’s among the most compelling bits of proof out there that human beings are behind global warming, and as such has become a target on Mann’s back for climate denialists looking to draw a bead on scientists. — The Atlantic, March 9th
Global Temperatures Highest in 4,000 Years The modern rise that has recreated the temperatures of 5,000 years ago is occurring at an exceedingly rapid clip on a geological time scale, appearing in graphs in the new paper as a sharp vertical spike. — Justin Gillis, New York Times, March 7th
Study: Recent heat spike unlike anything in 11,000 years “Rapid” head spike unlike anything in 11,000 years. Research released Thursday in the journal Science uses fossils of tiny marine organisms to reconstruct global temperatures …. It shows how the globe for several thousands of years was cooling until an unprecedented reversal in the 20th century. — Seth Borenstein, The Associated Press, March 7th
True face of climate’s hockey stick graph revealed The rate of warming in the last 150 years is unlike anything that happened in at least 11,000 years, says Michael Mann of the Pennsylvania State University in University Park, who was not involved in Marcott’s study. — Michael Marshall, New Scientist magazine, March 7th
Now, Ross McKitrick, building on the work of Steve McIntyre and others in the blogosphere, shows how easily these media outlets were duped into believing this study was the end-all for proof of man-made climate change.
We’re not screwed?
11,000-year study’s 20th-century claim is groundless
On March 8, a paper appeared in the prestigious journal Science under the title A reconstruction of regional and global temperature for the past 11,300 years. Temperature reconstructions are nothing new, but papers claiming to be able to go back so far in time are rare, especially ones that promise global and regional coverage.
The new study, by Shaun Marcott, Jeremy Shakun, Peter Clark and Alan Mix, was based on an analysis of 73 long-term proxies, and offered a few interesting results: one familiar (and unremarkable), one odd but probably unimportant, and one new and stunning. The latter was an apparent discovery that 20th-century warming was a wild departure from anything seen in over 11,000 years. News of this finding flew around the world and the authors suddenly became the latest in a long line of celebrity climate scientists.
The trouble is, as they quietly admitted over the weekend, their new and stunning claim is groundless. The real story is only just emerging, and it isn’t pretty.
Read his excellent essay in full at The Financial Post here: