Study debunks 'global cooling' concern of '70s

— -- The supposed "global cooling" consensus among scientists in the 1970s — frequently offered by global-warming skeptics as proof that climatologists can't make up their minds — is a myth, according to a survey of the scientific literature of the era.

The '70s was an unusually cold decade. Newsweek, Time, The New York Times and National Geographic published articles at the time speculating on the causes of the unusual cold and about the possibility of a new ice age.

But Thomas Peterson of the National Climatic Data Center surveyed dozens of peer-reviewed scientific articles from 1965 to 1979 and found that only seven supported global cooling, while 44 predicted warming. Peterson says 20 others were neutral in their assessments of climate trends.

The study reports, "There was no scientific consensus in the 1970s that the Earth was headed into an imminent ice age.

"A review of the literature suggests that, to the contrary, greenhouse warming even then dominated scientists' thinking about the most important forces shaping Earth's climate on human time scales."

"I was surprised that global warming was so dominant in the peer-reviewed literature of the time," says Peterson, who was also a contributor to the United Nations' Intergovernmental Panel on Climate Change 2007 report.

Scientific reports in the past decade, most notably the U.N. panel's Nobel Prize-winning efforts, have warned that human activities are warming the planet by increasing the release of heat-trapping "greenhouse" gases into the atmosphere.

Skeptics have argued that climate change is cyclical, not fueled by the burning of fossil fuels — coal, oil and natural gas. Peterson notes in the study that concerns over the frigid 1970s subsequently became representative of scientific division over global warming.

That was an unusually cold decade, especially the later years, across the Northern Hemisphere. In the USA, the winters of 1977-79 were three of the 11 coldest since the recording of temperatures began in the 1890s, according to climate center data. The winter of 1978-79 remains the coldest on record in the USA.