Last year was the hottest on record for the third consecutive pass of the calendar. Glaciers and polar ice melt, plant and animal species go extinct at a rapid rate, and sea levels rise. Clearly the consequences of climate change are immense.
Does anyone out there think we’re at the dawn of a new ice age?
If we had asked that question just 40 years ago, an astonishing number of people — including some climatologists — would have answered yes. On April 28, 1975, Newsweek published a provocative article, “The Cooling World,” in which writer and science editor Peter Gwynne described a significant chilling of the world’s climate, with evidence accumulating “so massively that meteorologists are hard-pressed to keep up with it.” He raised the possibility of shorter growing seasons and poor crop yields, famine, and shipping lanes blocked by ice, perhaps to begin as soon as the mid-1980s. Meteorologists, he wrote, were “almost unanimous” in the opinion that our planet was getting colder. Over the years that followed, Gwynne’s article became one of the most-cited stories in Newsweek’s history.
And Gwynne’s was no lone voice, at least in the popular press. Scores of similar articles, some with even more dire predictions of a “little ice age” to come, appeared during the 1970s in such mainstream publications as Time, Science Digest, The Los Angeles Times, Fortune, The Chicago Tribune, New York Magazine, The New York Times, The Christian Science Monitor, Popular Science, and National Geographic. A worldwide freeze proved irresistible to feature writers prowling for a sexy news peg. “The media are having a lot of fun with this situation,” observed climatologist J. Murray Mitchell.
We now see that these forecasts were badly off course, but how did climate science go so wrong? The quick answer is that it didn’t.
A Young Science
The scientific study of the climate is not very old. Compilations of global temperature data started in the 1870s, and not until 1963 did J. Murray Mitchell bring together information from hundreds of weather stations around the world to build a modern representation of Earth’s temperature. His work suggested a steady increase in global temperatures from around 1880, followed by a cooling of the planet from about 1940. In addition, satellites of the early 1970s spotted more snow and ice across the Northern Hemisphere, and people were well aware of unusually harsh winters in North America during 1972-73.