In his May 21 essay (“What constitutes well-established science?”), Mr. Jay Smith does a disservice to your readers by misrepresenting what is known about human-caused climate change.
Mr. Smith asserts his right to redefine “well-established science” to be whatever he wants it to be. Never mind that the U.S. National Academy of Sciences (founded by Abraham Lincoln), and all of the scientific societies in the U.S. that have weighed in have concluded that climate change is real and caused by fossil fuel burning. Never mind that 97 percent of publishing scientists have concluded the same thing (despite Mr. Smith’s protestations to the contrary). Never mind that the U.S. Navy views climate change as a threat to our national security, recognizing for example that sea level rise threatens the largest Naval installation in the U.S., close by in Norfolk .
Nearly every one of Mr. Smith’s assertions is a at best a half-truth, and at worst a plain untruth. This is especially true with regard to his false statements about the "hockey stick" reconstruction -- work of my own published more than a decade ago that shows the recent warmth to be unprecedented in at least 1,000 years.
The hockey stick has taken on an iconic significance in the climate change debate, and as a result it continues to be attacked by industry front groups, fossil fuel-funded politicians and industry hired guns who are opposed to reductions in fossil fuel burning. Many, like Mr. Smith, parrot their propaganda. I describe my experiences at the center of these attacks in my book “The Hockey Stick and the Climate Wars”.
Mr. Smith attempts to give readers the impression that my work has been refuted and discredited. He describes an alternative universe in which, if you are to believe him, the National Academy of Sciences supposedly “debunked” the graph.
In reality, the National Academy of Sciences affirmed my research findings in an exhaustive independent review published in June 2006 (see e.g. "Science Panel Backs Study on Warming Climate", New York Times, June 22, 2006).
In the decade and a half since our original published work, several dozens of scientific groups have independently reproduced, confirmed, and indeed extended our original findings. Most recently, a team of nearly 80 scientists from around the world, publishing in the premier journal Nature Geoscience, came up with a nearly identical result.
Despite Mr. Smith’s assertion to the contrary, the most recent report of the Intergovernmental Panel on Climate Change (the most authoritative assessment of climate science available) concluded that recent warmth is likely unprecedented over an even longer timeframe than we had concluded (at least the past 1400 years). Of course, the “hockey Stick” is only one of numerous independent lines of evidence that have led the world’s scientists to conclude that climate change is (a) real, (b) caused by the burning of fossil fuels, and (c) a grave threat if we do nothing about it.
Readers interested in learning what the actual science has to say should consult scientist-run websites like skepticalscience.com, or books on the topic like my own “Dire Predictions: Understanding Climate Change” (the 2nd edition highlighting the most recent science is now available). Here in Virginia, and elsewhere, we must get past the unworthy debate about whether or not a problem exists, and on to the worthy debate about what to do about it.
Michael E. Mann is a Distinguished Professor in the Department of Meteorology, Penn State University, and director of the Penn State Earth System Science Center.