Turn to facts when considering climate changes

John Babush did a disservice to your readers by spreading falsehoods about climate science in his recent letter (“Research more into global warming,” Opinion page of Thursday, July 3, 2014, edition).

Mr. Babush promotes discredited talking points, denying that polar ice is decreasing (Arctic sea ice is in fact disappearing even faster than climate models have predicted) or that polar bears are at risk because of this (polar bears have in fact been listed by the U.S. government as "threatened species" for this reason; citing the fact that one isolated population's numbers are increasing, when that was actually a result of hunting restrictions, is mendacious at best). Babush also promotes the industry-funded
"climategate" smear campaign, where thousands of scientists emails were stolen and then misrepresented by climate change deniers in an effort to call into question the evidence for human-caused climate change. Babush conveniently fails to acknowledge that nine different investigations in the U.S. and Europe established that there was no evidence of impropriety in any of these emails.

Babush makes untruthful allegations about the “hockey stick” – work of my own published more than a decade ago showing that recent warming is unusual over at least the past 1,000 years. He parrots the false allegation that our methodology “gives the same result even when totally random data is fed into it.” That dishonest claim has been thoroughly refuted in the actual peer-reviewed scientific literature. The highest scientific body in the nation, 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).

Dozens of independent groups of scientists have independently reproduced and confirmed our findings, including most recently an international team of nearly 80 scientists from around the world, publishing in the premier journal Nature Geoscience.

Readers interested in the truth behind the science, rather than the falsehoods and smears perpetuated by individuals like Mr. Babush, should consult scientist-run websites like realclimate.org and skepticalscience.com, and books on the topic like my “The Hockey Stick and the Climate Wars” and “Dire Predictions: Understanding Global Warming.”

Michael E. Mann

Distinguished Professor, Dept. of Meteorology, Penn State University

Director, Penn State Earth System Science Center