Global Warming Or Climate Change? What’s The Difference?

June 2nd, 2015 by Sandy Dechert

Earth’s atmosphere has really started groaning under the burden of too much carbon dioxide. But should we call the phenomenon “global warming,” or “climate change”? People often use the terms interchangeably.

The answer is that it depends. One thing for sure, neither term should be mistaken for “weather.” Weather (sunshine, precipitation, wind, temperature, humidity) happens right now, today; climate aggregates a succession of weathers. We can only observe climate after the passage of time—three months, 30 years, centuries, millennia, ice ages and interglacials, or even entire epochs.

Looking at history, scientists started talking about “climate change” first, and use it more frequently, as shown in this Skeptical Science timeline drawn up from academic search hits on Google Scholar over the past 75 years.

If you measure from a Google Books 1970-2007 chart (below) how often the subject of CO2-prompted atmospheric change has appeared in books in the United States during this period, you’ll see an indication that the terms climate change and global warming intertwine so closely that no preference has emerged until quite recently. Both charts show that the use of “climate change” has increased.

It seems that the real importance of the graphs lies not in which term is “right,” but in the fact that we’re paying more attention to both global warming and climate change since the late 20th century, and even more urgently during the most recent years.

Finally, a third Google-derived chart (Google Trends) covering the 2004-2014 decade reveals yet a different picture. This one clearly shows “global warming” as the predominant term, peaking at the time of the Nobel Prize award to the IPCC and Al Gore and a more even view from 2011-2014. Several explanations may account for this. You’ll encounter my own at the end.

You’ll find each term used in the scientific literature, but with a subtle difference.Planetsave asked climate scientist Michael E. Mann, who first drew the famous hockey stick curve in 1999, leading to the 2007 Nobel Prize for the Intergovernmental Panel on Climate Change team, to spell it out.

The Hockey Stick Curve

Dr. Mann says:

“I see them as different attributes of the same phenomenon. ‘Global warming’ simply describes the surface warming of Earth due to increased greenhouse gas concentrations. ‘Climate change’ describes the fuller range of impacts (i.e., shifting rainfall and drought patterns, changes in ocean circulation, melting ice, sea level rise, etc.). But as for the ‘hockey stick,’ since it is indeed an estimate of surface temperature alone, ‘global warming’ seems the more appropriate characterization.”

Climate change factors, which include global warming (epa.gov)

So the actual scientific difference between the terms is causal. Other experts and observers bear this out. Because it refers to the overall pattern, “climate change” is more inclusive. It encompasses all the effects Dr. Mann describes beyond simple temperature rise, and more. The “greenhouse effect”is at the root of both.

Now for the really complex question: how do ordinary people describe the phenomenon? Here the correct answer has to be “it’s complicated.” The words appear to mean different things to different subpopulations (sex, age, political party, etc.). Worse yet, many surveys have asked these questions, and the answers are regrettably inconsistent.

If we examine the specific use of these terms as several sources present them, neither turns up early. “Climatic change” appears to have been the first descriptor. Our sources find it used by Plass (1956), Benton (1970), and Broecker (1975), among others. In Congressional hearings in 1975, however, testimony referred to “global warming.” The Charney report of 1979 used both, and correctly. For a while, NASA called the phenomenon “inadvertent climate modification.”

In 1988, Jim Hansen, the first climate scientist to testify before Congress on the subject, talked about “global warming.”

“Global warming has reached a level such that we can ascribe with a high degree of confidence a cause and effect relationship between the greenhouse effect and the observed warming.”

But also that year, the World Meteorological Organization and United Nations Environment Programme founded an Intergovernmental Panel on Climate Change. Shortly thereafter a series of annual international meetings arose called United Nations Framework Conventions on Climate Change.

The Union of Concerned Scientists stuck to “global warming,” but the National Academy of Sciences preferred the other term. In the late 1980s excitement flared briefly over “global change,” a term that has since occurred off and on in US government parlance; and NASA insisted on “global climate change” for a while. Phil Plait (@BadAstronomer)  uses both, and correctly. Senator Jim Inhofe, the guy who brought the snowball into the Senate chamber, liked “global warming” at that point.

Taking a rough count of about 25 polls taken over the past two years, we find that about twice as many polls called the phenomenon “climate change” than those that used the term “global warming.” In other words, two-thirds of the pollsters used the scientifically correct term rather than “global warming.” Several used other terms or used both interchangeably. But did the language of the queries bias the poll results and the national perspective? Good question, no answer.

A nationally representative survey from Yale found Americans equally familiar with both terms, but four times more likely to say they hear the term global warming in public discussion, on the news, and so on. They were said to be twice as likely to remark that they personally use the term “global warming” in their own conversations.

We have not yet found any information on the preferences of men vs. women about the two terms, but the following findings of Yale’s What’s In A Name? Global Warming vs Climate Change, May 2014) on differences by sex are instructive:

• Men are more certain than women that the phenomenon is happening.
• Men tend to worry more intensely about the issue.
• Women feel a greater sense of personal threat.
• Women issue higher priority ratings for action by the president and Congress.
• Men are more willing to join a campaign to convince elected officials to take action.

Robert P. Jones, Daniel Cox, and Juhem Navarro-Rivera, the authors of the November 2014 Religion, Values & Climate Change Survey from the Public Religion Research Institute and American Academy of Religion (funded by The Nathan Cummings Foundation and The Ford Foundation), also provide some detailed breakdowns.

On political differences, 2013 Pew Research Center statistics on “climate change” break out as shown above. Although the domestic stats show no terminology difference, the international statistics there are also interesting.

The 2014 Pew studies characterize the difference as a “stark partisan divide”–though not as stark as the split mentioned a year before.

The PRRI/AAR study summarizes a variety of religious views on climate concern:

Yale gives us a good look at how people judge their own familiarity with the import of the terms and whether they connote good or poor results overall.

Nature Climate Change published an intriguing theory just last week from writers at the University of Maryland, Exeter University (UK), and the National Socio-Environmental Center in Annapolis that dissected the role of “echo chambers” (situations where people surround themselves with information they want to hear, and block out the rest) in public perception of climate issues. The study takes on both climate politics and the relationship between science communication and policymaking. They credit echo chambers such as Fox News for the fact that more than 56% of Congressional Republicans deny climate change.

“Because of the way some echo chambers form, minority opinions can be repeated and repeated, so it amplifies their perspective.”

Finally, “climate change” and “global warming” can be confused because “climate change” is sometimes used to refer specifically to alterations caused by human activity, also called “anthropogenic global warming.” Media Matters For America has fallen victim to this narrow interpretation.

Below are some words and concepts Americans associate with “global warming” and “climate change” and their reported incidence.

As a lay person (“I am not a scientist”), I prefer to use “climate change” as the umbrella term, not just because scientists prefer it, but because I see a slight preference for it in international English, which includes not only the American English discussed here, but also UK English, UN English, India English, Australia English, all the current and former colonial Englishes on earth, as well as “Standard Broadcaster” English. But that’s just my own small contribution, and I have zero statistics to back it up.

I can think of no modern expression better than “mind-boggling” to convey the extent to which some people will go to include personal views in their descriptions of an observable phenomenon. As well as the two main terms and other monikers noted above:

• Fresh Energy likes “climate chaos.”
• Thomas Friedman of The New York Times favors “global weirding.”
• Joe Romm, founding editor of Climate Progress, likes that a lot too, but his favorite is “Hell and High Water.”

“Climate disruption” may be the newest and strongest term, if it catches on. It avoids the temperature rise connoted by “warming,” still conveys the sense of immediacy in that term, and implies the global nature of its extent by specifying only “climate,” not referring to whose climate.

The “climate disruption” parlance was common at the Lima COP20 meeting last December, the Royal Society uses it, and France’s influential Environment Minister Segolene Royal uttered it on Saturday in an interview with The Associated Press before her trip to the US.

To conclude, created by more gases trapped in the atmospheric greenhouse than what’s optimal for current residents of Earth, global warming is just a subset of climate change—but arguably the most critical part, because it drives other changes with potential for yet more disaster. As former US vice-president Al Gore said four years ago, “What hangs in the balance is the future of civilization as we know it.”

Next time someone comes up to you expressing fears about global warming, you can simply say, “Yes, but you should hear about climate change”–or maybe “climate disruption.” (On this topic, a good sense of humor goes a long way.)

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