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Speaker 1: This Day in History Class is a production of iHeartRadio.

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Speaker 1: Hello and Welcome to This Day in History Class, a

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Speaker 1: show that uncovers a little bit more about history every day.

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Speaker 1: I'm Gabe Lucier, and in this episode, we're looking at

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Speaker 1: how global warming became a household word and why it

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Speaker 1: was eventually eclipsed in the public's mind by climate change.

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Speaker 1: The day was August eighth, nineteen seventy five. American geochemist

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Speaker 1: Wallace Broker coined the term global warming. He first used

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Speaker 1: it in the title of a scientific paper he wrote

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Speaker 1: called Climate Change. Are We on the Brink of a

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Speaker 1: pronounced Global Warming? The paper was published on August eighth

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Speaker 1: in the journal Science, and it served as an early

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Speaker 1: warning that the Earth's average surface temperature sure would rise

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Speaker 1: in the coming years due to increasing greenhouse gas emissions.

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Speaker 1: Broker was among the first scientists to predict that the

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Speaker 1: planet would warm, and by the time of his death

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Speaker 1: in twenty nineteen, his prediction had come true. At the

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Speaker 1: time of Broker's paper, the scientific community already had an

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Speaker 1: established term for humanity's impact on climate. It was called

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Speaker 1: inadvertent climate modification. And if that sounds a little vague,

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Speaker 1: that's because it was meant to be. Many scientists of

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Speaker 1: the era believed that human activities could lead to changes

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Speaker 1: in the climate, but they weren't exactly sure which way

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Speaker 1: that change might go. One possibility was that the industrial

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Speaker 1: emissions of aerosol particles might cause global cooling, but on

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Speaker 1: the other hand, greenhouse gas emissions could lead to global warming.

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Speaker 1: For most of the nineteen seventies, scientists didn't know which

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Speaker 1: effect would gain the upper hand, and that sense of

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Speaker 1: uncertainty was reflected in the term they chose inadvertent climate modification.

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Speaker 1: But by nineteen seventy five, Wallace Broker felt confident that

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Speaker 1: he had finally figured out in which direction the climate

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Speaker 1: would be modified. His first breakthrough came five years earlier,

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Speaker 1: when he published a study of ocean sediment cores. While

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Speaker 1: working as a researcher at Columbia University. Broker discovered that

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Speaker 1: the ice age had experienced rapid transitions in climate. Thick

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Speaker 1: sheets of ice would form over the course of tens

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Speaker 1: of thousands of years of freezing temperatures, only for a

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Speaker 1: sudden onset of warm weather to melt the ice, and

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Speaker 1: then the cycle would start all over. Broker built on

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Speaker 1: those findings in his nineteen seventy five paper, arguing that

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Speaker 1: the planet was likely headed toward a similar sudden shift

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Speaker 1: to warmer weather. The present cooling trend, he wrote, will

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Speaker 1: within a decade or so give way to a pronounced

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Speaker 1: warming induced by carbon dioxide. Early in the next century.

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Speaker 1: It will have driven the mean planetary temperature beyond the

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Speaker 1: limits experienced during the last one thousand years. Broker was

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Speaker 1: the first to assert in print that global warming was

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Speaker 1: the form that inadvertent climate modification would ultimately take, but

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Speaker 1: other scientists soon came to the same conclusion. In nineteen

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Speaker 1: seventy nine, for example, the National Academy of Science published

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Speaker 1: its first conclusive study on carbon dioxide's impact on climate,

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Speaker 1: and tellingly, the study adopted Broker's term, referring to surface

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Speaker 1: temperature change as global warming. These days, there's a good

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Speaker 1: deal of public confusion over the distinction between global warming

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Speaker 1: and climate change. Some people have even claimed the term

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Speaker 1: climate change was introduced recently as a replacement for global warming.

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Speaker 1: In reality, though both terms have existed concurrently for decades.

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Speaker 1: For instance, both appear in the title of Broker's nineteen

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Speaker 1: seventy five paper, climate Change, Are we on the brink

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Speaker 1: of a pronounced global warming. He wasn't using the terms

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Speaker 1: interchangeably either, Just like today, they each carried their own

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Speaker 1: distinct meaning. Global warming is one result of climate change, namely,

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Speaker 1: it's the increasing of the Earth's surface temperature. But temperature

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Speaker 1: change isn't the only effect of a change in climate,

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Speaker 1: and it isn't the most severe one either. For example,

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Speaker 1: the warming of surface waters in the ocean causes more

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Speaker 1: ice to melt into fresh water, which in turn causes

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Speaker 1: the sea level to rise. And then there are changes

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Speaker 1: to precipitation patterns, with more rain falling in some regions

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Speaker 1: and less rain falling in others. Those kinds of fluctuations

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Speaker 1: could have serious consequences on agriculture and wildlife to an

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Speaker 1: even greater degree than the higher temperatures alone. Put simply,

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Speaker 1: climate change is an umbrella term for any lasting change

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Speaker 1: to the Earth's climate brought about by human ans activity,

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Speaker 1: and global warming is one of the many results of

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Speaker 1: climate change. Within scientific journals, that usage has remained consistent

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Speaker 1: ever since the terms were introduced, but in the mainstream media,

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Speaker 1: some authors and editors tend to use one term when

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Speaker 1: they really mean the other. Many outlets have gotten better

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Speaker 1: about that in recent years, and the result is that

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Speaker 1: climate change is now used much more often than global warming.

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Speaker 1: But don't get too excited. The switch doesn't mean that

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Speaker 1: the planet isn't still getting warmer. It just means that

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Speaker 1: more people are realizing, just as Broker hoped they would,

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Speaker 1: that global warming isn't the only result of mankind's tampering

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Speaker 1: with the climate. The collective hope now is that we

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Speaker 1: can do something with that knowledge before it's too late, because,

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Speaker 1: as Broker put it in nineteen ninety eight quote, the

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Speaker 1: climate system is an angry beast and we are poking

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Speaker 1: it with sticks. I'm Gabe Lucier and hopefully you now

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Speaker 1: know a little more about history today than you did yesterday.

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Speaker 1: If you'd like to keep up with the show, you

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Speaker 1: can follow us on Twitter, Facebook, and Instagram at TDI

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Speaker 1: HC Show, and if you have any comments or suggestions,

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Speaker 1: feel free to pass them along by writing to This

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Speaker 1: Day at iHeartMedia dot com. Thanks to Chandler Mays for

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Speaker 1: producing the show, and thanks to you for listening. I'll

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Speaker 1: see you back here again tomorrow for another Day in

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Speaker 1: History Class