A newly released report out of Yale and George Mason University should be required reading for anyone attempting to write about the climate. Researchers examined the public reaction to two catch phrases many science writers use interchangeably: Global warming and climate change.
It’s not too surprising that the study revealed a much stronger, more emotional reaction to the phrase “global warming”. It’s a more pointed, more specific expression. Climate change is vague, nebulous, and carries a whiff of political correctness.
Science writers and scientists often assume it’s understood that when they say climate change, they are referring to consequences of human-generated greenhouse gas buildup – consequences that can include global warming as well as changes in wind, ocean currents and rainfall patterns. The report says this was a faulty assumption. People associated global warming with human activity, but they did not make the same connection with climate change. They aren't sure what climate change is supposed to mean.
Here’s a snippet from the results:
We found that the term global warming is associated with greater public understanding, emotional engagement, and support for personal and national action than the term climate change.
For example, the term global warming is associated with: Greater certainty that the phenomenon is happening, especially among men, Generation X (31-48), and liberals;
In the Guardian, Susan Goldenberg summed up the results of the survey and added a fascinating piece of background:
George W Bush swapped the term climate change for global warming in 2002, on the advice of the Republican political consultant, Frank Luntz.
In a secret memo before the mid-term elections, Luntz warned Republicans – and Bush in particular – were singularly weak on the environment. He advised a strategy of disputing climate science, and of avoiding the term "global warming' because of its highly negative connotations.
“It's time for us to start talking about 'climate change' instead of global warming … 'climate change' is less frightening than 'global warming',” said the memo obtained by the Environmental Working Group.
The confusion stuck.
This is telling. The term climate change was pushed by politicians who didn’t want Americans to demand action.
In his New York Times blog, Andrew Revkin noted that people have tried to find more accurate and evocative ways to describe the result of accumulating greenhouse gases:
He also quoted a source outside the study, though it doesn’t appear to be a new interview:
Global warming should dominate for other reasons. As Roger A. Pielke, Jr., has pointed out for a decade, “climate change” has proved problematic in a more technical sense — with the Intergovernmental Panel on Climate Change and United Nations Framework Convention on Climate Change defining the term differently, in ways that have significant ramifications in treaty negotiations. (The climate panel definition includes both human-driven and natural change; the treaty process only deals with climate change driven by the buildup of greenhouse gases.)
At Time, Bryan Walsh included some of his own experience as a science writer deciding which term to use:
While the two terms are largely synonymous—which is why there are 472 posts where I use both—”climate change” has become the preferred term for scientists because it better describes the long-term changes in the planet’s climate, which go well beyond simple temperature increase. Scientists use it, and so have I, but most of the time I simply rotate the two terms for variety’s sake.
At Slate, Eric Holthaus covered the report under the headline: Study, Global Warming is Scarier than Climate Change. He included some of the longer-term history of the terminology but missed the secret memo:
In general, it’s more scientifically accurate to talk about the problem as “climate change.” That term (which dates back to 1956) was in use scientifically almost 20 years before “global warming” (1975). Global warming—the long-term rise in Earth’s average temperature, brought about by the increasing concentration of heat-trapping gases emitted by human activity—is a subset of climate change, which refers to a broader plethora of effects, like ocean acidification, rising sea levels, and crazier weather.
Scientists typically prefer to talk about “climate change.” That’s because humans don’t “feel’ temperature on a global scale.
Since we’re on the subject of word and phrase choices, “broader plethora of effects” does not work. Plethora is a great word, but it refers to an overabundance or glut.
But more importantly, it’s disapopinting that the Slate and Time pieces tell us what scientists think without quoting any scientists. The only outside source who crops up – Pielke Jr. in Revkin’s post – finds fault with the term climate change. These pieces all need some live voices from climate scientists to tell us whether they indeed prefer the term climate change and where they feel it’s important to make a distinction.
Since the use of these two catch phrases matters a lot for science journalists, I thought I’d consult two top climatologists who’ve also proven to be gifted communicators. Here’s Michael Mann from Penn State University, author of The Hockey Stick and The Climate Wars:
This is always a frustrating discussion to many of us in the climate science community, because to us, these are two equally appropriate, complementary terms that describe different aspects of the same phenomenon. Global warming is perhaps the single most robust response of the climate system to increasing greenhouse gas concentrations. The underlying physics is very simple—we know that the surface of the Earth must warm in response to increasing greenhouse gas concentrations. But there are many other response of the climate to increasing greenhouse gas concentrations that are equally or more significant from a societal impacts standpoint. Sea level rise (which is a result of the warming of the oceans, the melting of the ice), shifting wind and ocean currents, changing rainfall and drought patterns, changes in the frequency and intensity of extreme meteorological phenomena, these are all potential impacts of human-caused greenhouse warming of the planet.
That having been said, outside the lexicon of science, the terms do seem to have taken on very different connotations. In my book, I talk about the infamous “Luntz Memo” of 2002, where Republican pollster Frank Luntz advised opponents to regulation of carbon emissions that they should use the term “climate change” rather than “global warming” because it sounds less threatening. The irony is that the critics [claim] scientists use “climate change” because it sounds more threatening—the opposite of what Luntz had determined from his polling and focus groups! And of course, the reason that we use the term “climate change” more often is that, as I discussed above, it describes a far more general phenomenon of which the warming of the surface of the Earth (“global warming”) is simply one feature…
And here’s Richard Alley, also from PSU, author of Earth: The Operator’s Manual:
I have used both terms, choosing the one that is more appropriate. (You can see this in, e.g., my book Earth: The Operators’ Manual; I paste the two relevant entries from the Index below…) Burning fossil fuels and releasing the CO2 to the atmosphere turns up the planet’s thermostat, causing global warming (or, more accurately, globally averaged warming; warming will occur unless a cause of similar-sized or bigger cooling is also introduced). The global warming in turn will cause many other climate changes, including an increase in the most intense rainfall events, expansion of the subtropical dry zones, drying of many grain-belt regions in summer, etc. The global warming is very strongly supported by physical understanding, a range of models, and fingerprinting exercises with recent data; the others I mentioned are strongly supported. Global warming from our greenhouse gases is part of climate change, but it is so well understood that failure to call it out specifically deprives readers or listeners or viewers of important information.
Suppose you compared the effects of our CO2 to the effects of the change in North Atlantic circulation at the end of the Younger Dryas. When the waters off Norway returned to sinking rather than freezing in the winter about 11,600 years ago, the climate changed notably in most places around the world, with warmer winters in the north, stronger monsoonal rains in India and probably China, a northward shift of the tropical circulation, cooling in the far south, and more. But, the globally averaged temperature change seems to have been small—a rise in methane linked to the monsoons and thawing of northern permafrost gave a little warming, and the ice-albedo shifts in the north were probably a little stronger than in the south, so in total the world warmed a little, but although still with cooling in the south. Any communication that emphasized the global mean temperature change of the end of the Younger Dryas, rather than the pattern of changes, would miss most of the story, which is more of circulation changes, or regional climate changes, than of global warming.
Our CO2 will cause changes in circulation (one of Mike’s research topics), but the first thing almost everyone will notice when looking at a map of 20th-century observed and 21st-century projected changes is that (almost) everywhere warms. Hence, global warming with associated climate changes seems to me to be an accurate way to describe it.
I realize this post now contains a plethora of information, but I found the comments from Alley and Mann informative and helpful enough to include unabridged. Choosing the right phrase is always going to be a judgment call. This new study reminds us how important that choice can be.