Jack Elhai | Long Read | April 2017 | 6 minutes (1,500 words)
Last year was the third consecutive year of record heat. Glaciers and polar ice are melting, plant and animal species are rapidly becoming extinct, and sea levels are rising. It is clear that the impacts of climate change are enormous.
Does anyone think we are at the dawn of a new ice age?
If you had asked this question just 40 years ago, a surprising number of people would have said yes, including climate scientists. April 28, 1975 newsweek Author and science editor Peter Gwyn published a provocative article, “A Cooling World,” in which he argued that “so much evidence is accumulating that it is difficult for meteorologists to keep up with the world.” The climate has become significantly colder, he said. He said shortened growing seasons, crop failures, starvation and ice could disrupt transport routes, possibly starting as early as the mid-1980s. He wrote that meteorologists were “in general agreement” that the Earth was getting colder. Over the years that followed, Gwynne’s article became one of his most cited articles. newsweek‘s history.
And Gwynne was not alone, at least in the popular press. A number of similar articles, some including even more dire predictions of a “Little Ice Age,” appeared in mainstream publications during the 1970s, including: time, science digest, Los Angeles Times, Fortune, Chicago Tribune, new york magazine, New York Times, Christian Science Monitor, Popular Science, and national geographic. For feature writers on the prowl for sexy news, the global freeze was irresistible. “The media is having a lot of fun with this situation,” said climate scientist J. Murray Mitchell.
We now know that these predictions were way off, but why was climate science so wrong? The simple answer is that they weren’t.
young science
Scientific research on climate is not that old. Compilation of global temperature data began in his 1870s, and it was in his 1963 that J. Murray Mitchell assembled information from hundreds of weather stations around the world to construct a modern representation of global temperature. It was in the year. His research suggested that global temperatures had steadily increased since about 1880, and then the planet had cooled since about 1940. Additionally, satellites in the early 1970s discovered more snow and ice across the Northern Hemisphere, and people were familiar with the unusually harsh climate. Spent the winter in North America from 1972 to 1973.
As a result, suspicions spread among a small group of researchers that the world was getting colder, but a closer look at the data showed such conclusions to be flawed. The cooling was mainly localized to the Northern Hemisphere, and the colder temperatures pushed down the global average. Temperatures continued to rise in other parts of the world. Air pollution and aerosol use, which were reduced by legislation in the 1970s and 1980s, may also be a factor.
Several years ago, scientist Charles David Keeling began investigating changes in carbon dioxide levels by measuring the atmosphere from the summit of Mauna Loa and the Antarctic Pillar. By 1965, he discovered that his CO2 was rapidly increasing. In the same year, the President’s Council of Scientific Advisers recommended that CO2-related emissions could lead to disastrous increases in temperatures around the world.
So how widespread was concern about global warming? A 2008 survey of peer-reviewed scientific literature from the mid-1960s to the 1970s by a group of researchers found that concerns about global warming were It was found that the number of papers issuing warnings outnumbered those predicting cooling by a factor of six. As such, climate change in the form of global warming was a topic of widespread concern during this time, and there was no consensus that the Earth would cool in the near future.
Unbelievers make things even more complicated
But in later years, climate change deniers began to cling to the 1970s speculation that the planet was cooling as a way to discredit scientists who were sounding the alarm about rising global temperatures. Some contrarians point to an international conspiracy to suppress evidence of a supposed global cooling agreement. These deniers argue that not only is global warming wrong, but that the opposite of global warming may be happening. And in any case, how can you believe a scientist who claims one thing in a decade, and something completely different in another? Or who predicted a disaster that never happened, and now another?
In the 1970s, the study of global climate was still in its infancy. At the time, few meteorologists knew how to interpret temperature trend information, and the causes of climate change remained a mystery. The information climate researchers collected was incomplete and easily misunderstood. Since then, biological science has made great leaps forward, and many more scientists are now studying climate.
With far better technology and information available today, organizations such as the National Academy of Sciences, the American Association for the Advancement of Science, the National Climate Assessment, and the American Weather Association, to name just a few, are now able to: We declare that we have evidence of this. There is a strong belief that human activities are causing climate change and rising atmospheric temperatures. No peer-reviewed papers advancing the evidence for global cooling have been published in reputable scientific publications in recent decades. Meanwhile, thousands of studies showing evidence of global warming are published on the same page, and visible changes are already occurring. Surveys in 2009 and 2010 showed that 97% of climate scientists believe human activity is causing global warming. That’s an overwhelming majority.
humble withdrawal
From this point of view, newsweek The 1975 paper is a fascinating and meaningful artifact of a past scientific era. Indeed, making fun of incorrect predictions is easy and fun. It’s often humbling for a journalist to revisit old work, especially his articles from more than 40 years ago. But in recent years, Peter Gwynne has mustered up the courage to take another look at the Cool World.Writing in progress Inside the science mindan independent editorial publication of the American Physical Society in 2014, he described how he wrote his 1975 paper.
“While the hypotheses described in that original work seemed correct at the time, climate scientists now know they were seriously flawed,” Gwynne explains. did. Our climate is warming, not cooling, as the original story suggests. ” Simply put, climate science has evolved and advanced, resulting in new knowledge, he said.
(One of the climate scientists whose work Gwynne cited) newsweek This article has long argued that some aspects of this story are fundamentally correct. But George Kukla, who looked at satellite images showing increased snowfall over North America in the early 1970s, rejected the idea that significant sustained cooling was imminent. “No one expected this trend to continue uninterrupted,” he told an interviewer in 2007. Rather, he saw the ensuing warming as a cyclical and largely spontaneous precursor to the onset of cooling that would become apparent in mid-century. )
Gwynne acknowledged that while his article accurately captured the currents of meteorological thinking in the 1970s, it “didn’t tell the whole story at the time.” He omitted suggestive but inconclusive evidence that atmospheric carbon dioxide is increasing. He probably could not have known that efforts to reduce air pollution would soon erase the sharp drop in temperatures in North America and help it warm up.Gwynne also stated that he was too eager to write his own work. newsweek This article falsely suggested a link between global cooling and severe weather in the United States, which is an unwarranted leap. “I also predicted the future effects of global cooling on global food production, but there was little research to support this,” he writes.
Everyone makes mistakes, including science writers, but Gwynne confessed that she was most embarrassed by the unusual reception of her articles by climate change deniers. For example, U.S. Sen. James Inhofe (R-Okla.) cited a 1974 Time magazine article that asked, “Will there be another ice age?” In 2015, when he delivered a speech against climate change on the Senate floor, he had just held up a snowball as proof that it was still cold outside. 9 years ago newsweek I felt it necessary to publish an explanation for the lack of forethought in this story. “I’m worried that my obituary will be dominated by that one article. newsweek” Gwynn wrote.
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Jack Elhai I recently wrote about the Cherry Sisters, “vaudeville’s worst act,” in Longread. He writes about the history of science, medicine, and business, and about the relationship between current events and the past.