Scientists do not agree that humans cause global warming

Former U.S. Vice President Al Gore proclaims that scientists agree, "Humans are causing global warming." As proof, he cites a study in the journal Science by Naomi Oreskes, a professor at the University of California, San Diego.

She claims 100 per cent of the studies that addressed human influence on current climate trends either explicitly or implicitly endorse the view that humans are to blame for the current warming. Yet, researchers who tried to replicate her findings came up with quite different results, notes H. Sterling Burnett, a senior fellow with the National Center for Policy Analysis.

For example, Benny Peiser of John Moores University found that:

Nearly three times as many studies (3 per cent) either rejected or doubted that humans are a cause of the current warming as those that explicitly endorsed the "consensus view" that humans are causing warming (1 per cent).

Another 29 per cent implicitly accepted the consensus view, but most focused on the projected impacts of climate change rather than its causes.

Two-thirds of all of the studies either made no mention of human influence or dealt with methodological issues, possible responses to climate change or natural factors that contribute to it.

Another indication that there is no consensus on global warming is a survey that Hans von Storch and Dennis Bray conducted among their fellow climate scientists worldwide in 2003. They asked, "To what extent do you agree or disagree that climate change is mostly the result of anthropogenic (human) causes?"

Of the 530 responses, a majority (55.8 per cent) indicated moderate to strong support for the consensus view, while 30 per cent indicated varying degrees of scepticism.

The number of scientists who strongly disagreed with the consensus view (10 per cent) outnumbered those who most strongly supported it (9 per cent).

Contrary to Gore's claims, 55.8 per cent is hardly as strong a consensus as science ever produces about a theory, says Burnett.

Source: H. Sterling Burnett, The Truth about an Inconvenient Truth, National Center for Policy Analysis, Brief Analysis No. 561, June 22, 2006.

For text: http://www.ncpa.org/pub/ba/ba561/

For more on Global Warming: http://eteam.ncpa.org/issues/?c=science

FMF Policy Bulletin/ 27 June 2006