My 1975 ‘Cooling World’ Story Doesn’t Make Today’s Climate Scientists Wrong
It’s time for deniers of human-caused global warming to stop using an old magazine story against climate scientists.
Peter Gwynne - May 21, 2014
(Inside Science)—“The central fact is that, after three quarters of a century of extraordinarily mild conditions, the Earth seems to be cooling down. Meteorologists disagree about the cause and extent of the cooling trend, as well as over its specific impact on local weather conditions. But they are almost unanimous in the view that the trend will reduce agricultural productivity for the rest of the century.” – Newsweek: April 28, 1975
That’s an excerpt from a story I wrote about climate science that appeared almost 40 years ago. Titled “The Cooling World,” it was remarkably popular; in fact it might be the only decades-old magazine story about science ever carried onto the set of a late-night TV talk show. Now, as the author of that story, after decades of scientific advances, let me say this: while the hypotheses described in that original story seemed right at the time, climate scientists now know that they were seriously incomplete. Our climate is warming—not cooling, as the original story suggested.
Nevertheless, certain websites and individuals that dispute, disparage and deny the science that shows that humans are causing the Earth to warm continue to quote my article. Their message: how can we believe climatologists who tell us that the Earth’s atmosphere is warming when their colleagues asserted that it’s actually cooling?
Well, yes, we should trust them, despite the views of detractors such as comedian Dennis Miller, who brought my story to The Tonight Show in 2006. Several atmospheric scientists did indeed believe in global cooling, as I reported in the April 28, 1975 issue of Newsweek. But that was then. ...
The recent National Climate Assessment takes an equally emphatic view.
“What is new over the last decade is that we know with increasing certainty that climate change is happening now,” it states. “While scientists continue to refine projections of the future, observations unequivocally show that climate is changing and that the warming of the past 50 years is primarily due to human-induced emissions of heat-trapping gases.”
I’m sure it’s clear by now that I accept the views of the National Academy, National Climate Assessment, Mann, and the huge majority of his fellow climatologists. Nevertheless, websites devoted to denying the existence of human-caused climate change – or at least promoting the idea that nothing should be done about it – continue to use my article to validate their thinking. In fact the article has reportedly become the most-cited article in Newsweek’s history. ...
Those that reject climate science ignore the fact that, like other fields, climatology has evolved since 1975.
The certainty that our atmosphere is indeed warming stems from a series of rigorous observations and theoretical concepts
that fit into computer models and an overall framework outlining the nature of Earth’s climate.
These capabilities were primitive or non-existent in 1975. In fact my report reflected a real strand of climatological thinking back then. ...
Speaking personally, though, I accept that I didn’t tell the full story back then.
... “Three independent strands of science at the time got conflated in the articles: analyses of direct temperature data that showed a decline in temperatures particularly over the Northern Hemisphere since the 1940s; a very high level of pollution by sulfate aerosols that cooled the planet; and evidence that the timing of ice ages was caused by wobbles in Earth’s orbit,” explained Gavin Schmidt, deputy chief of NASA’s Goddard Institute for Space Studies, in New York. Indeed, he added, “some parts of the article are OK even today.”
At the same time, however, evidence had emerged of increases in the atmospheric concentration of carbon dioxide, a gas known to warm the atmosphere.
“The science was sort of speculative [in 1975],” Mann recalled. “A National Academy of Sciences report concluded there wasn’t enough information at that particular time because we had two competing forces – aerosols and greenhouse gases. It wasn’t entirely clear which would win out.”
Ironically, efforts to clean up the atmosphere made it possible to resolve the scientific mystery and convince climatologists that human activity is warming the planet. ... (there’s more!)