There was no way of knowing on Aug. 8, 1975, just how many readers turned to the new paper in the journal Science by geochemist Wallace Broecker, of Columbia University’s Lamont-Doherty Earth Observatory. It was hardly possible to track clicks or likes nearly half a century ago, so Broecker simply had to hope his message got through. It was a pressing one, conveyed directly by its headline: “Climatic Change: Are We on the Brink of a Pronounced Global Warming?”
The headline marked the first time the term “global warming” is known to have appeared in print, according to NASA. Though Broecker, who died in 2019 after devoting decades to studying and writing about climate change, might have hoped for more from his ground-breaking article, there was barely a whisper from the press or the public: The full-text database and search engine LexisNexis turns up only two uses of “global warming” in the five years that followed the Science piece—both of them in the magazine The Economist, during the blistering summer of 1977, when a heat wave led to a 24-hour blackout in New York City, resulting in 3,700 arrests, damage to 1,600 stores, and at least 1,000 fires.
Today, of course, things are much different. As we reach the official end of the hottest summer on record, our vocabulary is filled with different terms to describe the phenomenon that is causing all of the suffering: global warming, climate change, climate crisis. On Sept. 6., United Nations Secretary General António Guterres used a different, more ominous term: climate breakdown. A week later, a team of Danish researchers published a piece in Science that framed the problem in a different way. “Earth,” they wrote, “is now well outside the safe operating space for humanity.” During New York Climate Week, on Sept. 20 Guterres took it one step further saying the climate impacts showed that “humanity has opened the gates to hell."
Most planet-wide emergencies are not accompanied by all this linguistic shifting. People may have argued about how best to respond to the explosive emergence of COVID-19, but the overwhelming majority of us did agree that we were in a pandemic. Climate change, however, has had a host of labels since 1975—sometimes because our understanding of the science shifted, sometimes in the hope of arriving at just the right term so that climate deniers could be persuaded, and at other times in an attempt to convey urgency.
“What science is trying to do is draw our attention to the ways in which climate change is happening and the effects of that change,” says Kathleen Hall Jamieson, professor of communications and director of the Annenberg Public Policy Center at the University of Pennsylvania. “I think what we’re going to see is a deepening of the existing vocabulary.”
Just how quickly that deepening happens—how long it takes a new term describing a new crisis to seep into popular use—depends on the nature of the term, the nature of the crisis, and, often, the nature of the surrounding politics. Discussions of climate change began even before Broecker’s paper, without any of the white-hot rhetoric that has characterized much of our approach to the issue since. In 1973, a team of environmental scientists published a paper in MIT Press under the title “Study of Man’s Impact on Climate.” They labeled that impact “inadvertent climate modification.” The phrasing, while accurate enough, never caught on. NexisLexis counts just 11 uses of the term from 1968 to 2023, with the earliest occurring on Feb. 9, 1988, on a PBS program about math and science education.
“The first test when you’re speaking in a scientific voice is: Is it accurate? Does it encapsulate the science?” says Jamieson. Inadvertent climate change might do a good enough job of that, but it also may have come before its time. In 1971, the public wasn’t yet feeling the effects of climate change, and nobody was looking for a new term to describe something they didn’t know existed in the first place.
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Next up was Broecker’s “global warming” formulation—and it too got off to a slow start. There were just two citations of it in the media in the 1973 to 1978 window, and two from 1978 to 1983. As temperatures rose in the mid-to-late ‘80s use of the term crept up—to 301 uses from 1983 to 1988. Then everything changed. On June 23, 1988, NASA physicist and astronomer James E. Hansen testified before the Senate about global warming and its dangers, and made his points emphatically.
"The first five months of 1988 are so warm globally that we conclude that 1988 will be the warmest year on record unless there is a remarkable, improbable cooling in the remainder of the year," he said. "It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here."
Hansen may not have changed a lot of minds in Congress or in industry—climate denialism was just getting started and it has slowed efforts to shut off greenhouse gas emissions ever since—but the scientist’s words did resonate elsewhere. From 1988 to 1993, LexisNexis records more than 10,000 uses of the term in the media—a pace it has kept up in every five-year span since. Jamieson attributes a lot of that to the fact that the world had by then begun to heat up noticeably, and people could feel the change in real time.
“The speed with which the public can learn a vocabulary that is necessary to understand something salient to it is actually rapid,” she says.
Next out of the language gate was “climate change.” Broecker might have used a variation of the term—”climatic change”—in his 1975 study, but it wasn’t until 1979, when a group of meteorologists at the Woods Hole Oceanographic Institution in Woods Hole, Mass., published an influential paper known as the Charney Report, that the term went wide. Led by MIT meteorologist Jule Charney, the authors opted for the new phrase because it better captured the range of problems beyond warming that greenhouse gasses could cause, including, droughts, floods, superstorms, wildfires, loss of sea ice, and more.
“Climate change” caught on slowly—with only 46 citations from 1978 to 1983—likely due to the fact that it is less specific than global warming. “It’s about relevance, it’s about comprehensibility, it’s about how visual the language is,” says Jamieson. Still, as more and more scientists began to use “climate change,” so did the press and the public. From 1983 to 1988, there were 2,889 mentions of it in the media. Ever since, it has leapt to the same 10,000-plus level as global warming. Use of the term got a boost just before the midterm elections in 2002, when Republican pollster Frank Luntz wrote a memo to party leaders, urging candidates to address the environment because it was important to voters, and to use the term climate change instead of global warming. “While ‘global warming’ has catastrophic communications attached to it,” he wrote, “‘climate change’ sounds more controllable and less emotional.”
Read more: The IPCC Is Finally Using the Right Words to Talk About Climate Change Inequality and Justice
Decidedly more emotional is Guterres’s recent use of “climate breakdown.” He is widely credited with the term’s popularization, but it had actually already been in circulation, with 10,000-plus mentions in the 2018 to 2023 time frame. Still, when a term pops out of the mouth of the U.S. Secretary General it has a particular influence; 567 media uses of “climate breakdown” have been recorded since Gutteres’s remarks roughly two weeks ago. “Climate crisis” has also been at large for a while, but it was little used—in single and triple digits until 2003. Since then, however—as the situation has begun to look and feel crisis-like—it at last vaulted to the 10,000-plus range. “Global weirding,” coined by environmentalist and author Hunter Lovins, in 2007, to better capture the upside down nature of climate change—with snow where it should be hot and heat where there should be snow—has never gathered much momentum, with uses just in the triple digits in every five-year window after Lovins first spoke the words. While “weirding” is playful, it lacks the comprehensibility and specificity Jamieson says is necessary for scientific language to go wide.
Ultimately, what we call climate change doesn’t matter. The storms and volatility, extreme weather and temperature creep that are characteristic of it have been with us for more than five decades now. Words didn’t cause the problem and words won’t clean it up. That’s a job for all of us.
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Write to Jeffrey Kluger at jeffrey.kluger@time.com