Letter to the Editor—Debunking the 97% Consensus

Part eight in a ten-part series on the unsettled science of climate change from Grassroots Alberta

Not long ago, Sierra Club President Aaron Mair told a U.S. Senate hearing that the science of global warming “should not be up for debate.”

In response, one of the senators asked if it’s a frequent practice of the Sierra Club to declare areas of science beyond further consideration or discussion. Mair was then asked to explain how, “in the last eighteen years, satellite data shows no demonstrable [global] warming whatsoever?”

Rather than answer the question, Mair replied: “But, Senator, 97% of scientists… agree that there is global warming.”

This so-called consensus on global warming is something that climate alarmists and ambitious politicians drag around like a toddler with a favourite blanket. But who says that 97% of scientists agree? Where does that number come from?

It seems there are at least two sources. One arose from a survey conducted at the University of Illinois. The survey’s authors, Zimmerman and Doran, sent 10,357 surveys to scientists at academic and government institutions. Their key question: “Do you think human activity is a significant contributing factor in changing mean global temperatures?”

A total of 3,146 scientists (over 90% with Ph.D.s) responded. Rich Trzupek, a veteran environmental consultant, reports that the responses were not as expected. It was then determined, Trzupek says, that when respondents were rated as unqualified “to comment on the issue because they were merely solar scientists, space scientists, cosmologists, physicists, meteorologists, and the like,” the consensus picture improved.

More than 10,000 scientists had been invited to participate and over 3,000 responded, but in the end, respondents deemed “expert” enough to have an opinion that counts were whittled down to a mere 77.  When asked whether human activity is a significant contributing factor to global warming, 75 of those 77 answered “yes.”

Joe Bast and Roy Spencer explain a second source for the 97% allegation. Bast is president of the Heartland Institute, and Spencer is a climate scientist and U.S. Science Team leader on NASA’s Aqua satellite. Bast and Spencer explain that an Australian blogger, John Cook, and his friends reviewed abstracts published between 1991 and 2011. Cook reported that 97% of those stating a position (explicitly or implicitly) suggested that human activity is responsible for global warming.

Cook was quickly debunked when David Legates, former director of the University of Delaware’s Climate Research Center, and three others reviewed the same papers. They found that only “1% of the 4,014 expressing an opinion, and not 97.1 percent—had been found to endorse” the alarmist position on global warming.

Interestingly, at about the same time that Zimmerman and Doran were staking their original 97% consensus claim (based on 75 people), a survey by German climate scientist Hans von Storch was published. The German professor had polled climate scientists to rate the statement: “To what extent do you agree or disagree that climate change is mostly the result of anthropogenic [manmade] causes?” Responses came from 530 scientists, with only 9.4% strongly agreeing. Others were less convinced or not at all convinced.

The 97% consensus claim is alarmist fantasy. And further to that, real science is never about consensus anyway. Quantifiable outcomes and observable evidence are the language of science. Consensus is the language of politics.

About Grassroots Alberta

Grassroots Alberta Citizens Initiative was established to promote the responsible and efficient use of tax dollars and to carry out an educational role with respect to wealth creation and responsible public policy. Grassroots Alberta Citizens Initiative is a project of the Grassroots Alberta Landowners Association. “At the Grassroots” is a feature service of Grassroots Alberta. The author, Kevin Avram, is a director of Grassroots Alberta.