"A Consensus About Consensus"

[reason.on]

A Consensus About Consensus

By George Taylor 13 Feb 2006

"The vast majority of the most respected environmental scientists from all over the world have sounded a clear and urgent alarm. ...these scientists are telling the people of every nation that global warming caused by human activities is becoming a serious threat to our common future."

-- Al Gore, MoveOn.org, January 2004

"...the widely accepted notion among the vast majority of scientists [is] that human activity is contributing to a warming planet, and that business as usual -- doing nothing about rising levels of carbon dioxide in the atmosphere -- will make things worse."

-- Sandy Tolan and John Harte, San Francisco Chronicle, November, 2005

Statements such as these appear quite frequently, usually directed at those considered to be on the wrong side of "the widely accepted notion among the vast majority of scientists" that global warming is getting worse, and that it's caused by people -- notably, the people of the United States.

However, some scientists persist, "in the face of the overwhelming conclusions of scientists" in believing that natural variations are the primary cause of observed changes in climate. Without denying that human activities affect climate, these scientists believe that natural factors such as solar radiation, ocean temperatures, and other factors exert a much more significant influence.

As proof of their thesis Tolan and Harte referenced Naomi Oreskes. Last year Science Magazine published the results of a study by Ms. Oreskes. She concluded that there is a "unanimous, scientific consensus" on the anthropogenic (human-induced) causes of recent global warming. Oreskes analyzed 928 abstracts she found listed on a scientific database using the keywords "global climate change."

So what about this "consensus" among scientists. Is it really that broad?

Dr. Benny Peiser of England's John Moores University attempted to duplicate Oreskes' work. Peiser found 1,117 abstracts using the same search technique. Of these, only 13 explicitly endorsed the 'consensus view.' However, 34 of the abstracts rejected or questioned the view that human activities are the main driving force of "the observed warming over the last 50 years."

Oreskes claimed, "none of these papers argued [that current climate change is natural]". According to Peiser, however, 44 papers emphasized that natural factors play a major if not the key role in recent climate change.

Hans von Storch and Nico Stehr, European climate scientists, stated earlier this year that "a significant number of climatologists are by no means convinced that the underlying issues have been adequately addressed. Last year, for example, a survey of climate researchers from all over the world revealed that a quarter of respondents still question whether human activity is responsible for the most recent climatic changes."

That survey involved responses from 530 scientists worldwide. They were asked: "To what extent do you agree or disagree that climate change is mostly the result of anthropogenic causes?" Only 9.4% strongly agreed, while 9.7% strongly disagreed. Another 19.3% were in general disagreement.

But even if there actually were a consensus on this issue, it may very well be wrong. I often think about the lives of three scientists who found themselves by themselves, on the "wrong side of consensus." There have been many in the history of science, but I singled out Alfred Wegener (Continental Drift), Gilbert Walker (El Niño), and J. Harlan Bretz (Missoula Floods). None is well-known now among members of the public, and all of them were ridiculed, rejected, and marginalized by the "consensus" scientists -- and each of the three was later proven to be correct, and the consensus wrong. As a well-known writer once said, "if it's consensus, it isn't science -- and if it's science, it isn't consensus."

Wegener suggested that the continents were all connected at one time but had drifted apart, a phenomenon we now call "continental drift." Among his critics was Dr. Rollin T. Chamberlin, of the University of Chicago, who said, "Wegener's hypothesis in general is of the footloose type, in that it takes considerable liberty with our globe, and is less bound by restrictions or tied down by awkward, ugly facts than most of its rival theories." In time, though well after his death, Wegener's "footloose" theory became dominant.

Walker was chided for his belief that climatic conditions over widely separated regions of the globe could be linked, and that fluctuations in the tropical Pacific affected the Indian Monsoon and other climatic features. We now call those Pacific fluctuations the "El Niño-Southern Oscillation," and recognize that it has a profound effect on world weather.

Bretz postulated that massive floods had transformed the landscape of the Pacific Northwest at some time in the past. Geologists, who believed in slow, uniform processes, called Bretz a "catastrophist" because he believed in large-scale events not currently seen. Bretz engaged in "flaunting catastrophe too vividly in the face of the uniformity that had lent scientific dignity to interpretation of the history of the earth," according to one fellow scientist. Decades after his research began, it was shown that post-Ice Age floods had indeed scoured the landscape, and that Bretz's theories were correct.

When I hear the rather strident words of people like Tolan and Harte I am reminded of Wegener, Walker, and Bretz and what they went through. Many of my fellow climate scientists have been criticized for many years for their "non-consensus" views. They persist in seeking truth, regardless of government policies or popular opinion. No matter how many people agree.

George H. Taylor is the State Climatologist for Oregon and past President of the American Association of State Climatologists. The opinions expressed are his own and do not necessarily reflect those of the State of Oregon nor Oregon State University, where he is employed.