"Global warming" or "climate change"?
We should use the most accurate term. Remember that "climate change," now the most frequently used term, was introduced by Republicans in the US as a way to defuse public concern over the issue.
I’m currently working on a draft of an article on geoengineering — the risky idea of using human technology to cool the planet through some artificial means, so as to solve the warming problem, without having to stop using fossil fuels. One idea, for example, would be to inject various particles into the atmosphere to partially blot out the Sun’s light, thereby cooling the planet. The idea is gaining traction and, I think, there’s a good chance it will ultimately happen, though not for very good reasons.
That article should be finished soon. But, while writing, I find I keep encountering an issue of language I’ve stumbled over many times before. I want to write a short note just to settle the issue, which is: Should I use “global warming” or “climate change?” There’s a curious history to the usage of these two terms.
The latter term is now ubiquitous. The latest United Nations conference on the problem, COP27, was called the U.N. Climate Change Conference. Authorities generally refer to the one partially effective international agreement we’ve managed on the issue — The Paris Agreement of 2015 — as an “international treaty on climate change.”
Twenty years ago, however, the more common term in public discussions was “global warming,” even though its true that scientific studies have long used both terms to refer to different aspects of the issue (i.e. global warming as something that causes climate change). The term “climate change” has grown in usage to become about six times more popular over the past 18 years (I show some data on this a few paragraphs down the page).
What happened to cause the terminological shift, at least in public discussions? I think the history of this is not quite as widely known as it should be. The change in terminology did not happen by accident, but was pushed by Republicans in the US who wanted to introduce language they hoped would make the issue less threatening to the public. Their strategy worked, and worked so well that most public discussions of what to do about our warming planet now employ the term “climate change.”
Personally, I always try to use the term “global warming” if I’m writing about the challenge of reducing the consequences of greenhouse gas emissions. This is, I think, the most accurate description of the ultimate source of our troubles. Greenhouse gas emissions, of which carbon dioxide emissions are the most important, cause planetary warming by trapping heat within the atmosphere.
The mechanism is fairly simple. Sunlight streams more or less freely through the atmosphere to deliver energy to the planet’s surface. After being absorbed by matter — trees, air, oceans, solar cells, etc. — it ultimately ends up being re-radiated as lower-frequency thermal radiation associated with heat. All warm objects emit such radiation. Unfortunately, this light can then no longer travel so freely through the atmosphere. Rather, this heat radiation is partially absorbed and blocked by carbon dioxide and other greenhouse gases, preventing this heat from escaping to space.
The result is an energy imbalance — more coming in than going out — and global warming. There are good reasons to sometimes prefer the term “climate change,” most obviously when discussing not the root cause of our warming planet but the detailed consequences of such warming for our living environment. Warming might have all kinds of effects, from raising average temperatures to increasing the frequency of extreme weather events. These are climatic effects, or changes to climate caused by global warming.
But there is also a bad reason to use the term climate change when discussing the problem of excess planetary heating from greenhouse gas emissions. At least this other reason is “bad” from the point of view of anyone who honestly wants to confront the warming problem and find a way to preserve a stable climate. This reason, as first suggested by the Republican political strategist Frank Luntz, is to persuade people that global warming is not a serious issue.
“Climate change,” Luntz argued, is a term that generates a weaker response than global warming and, as a result, tends to demote the importance of the issue in the public mind.
Luntz was the advisor who pushed the Bush Administration in the early 2000s to shift its language in this way, bringing “climate change” into wider usage. He was, I must admit, very good at his job, and created a number of other charged linguistic terms which helped Republicans frame issues to their advantage. In his terminology, “inheritance tax” instead became the more offensive “death tax” and “offshore drilling” turned into the benign “energy exploration.”
In a famous memo, Luntz offered Republicans specific guidelines for approaching discussions of many problems linked to the environment, all designed to make the public more sympathetic to Republican positions. His suggestions on climate change were as follows:
It’s time for use to start talking about ‘climate change’ instead of global warming… ‘Climate change’ is less frightening than global warming. As one focus group participant noted, climate change ‘sounds like you’re driving from Pittsburgh to Ft. Lauderdale.’
While global warming has catastrophic connotations attached to it, climate change suggests a more controllable and less emotional challenge.
In a later interview, Luntz expressed regret that he ever played a role in opposing action on global warming, and also in helping to drive the coarsening of political interactions in the US. His early work was very effective, however, eagerly adopted and followed en masse by Republicans, and, as a result, we’re now in world where the more emotive and accurate term global warming is often replaced with the less worrying climate change.
The figure below shows data on google searches over the past 18 years or so, plotting the frequency of web searches for “climate change” versus those for “global warming.” The former terms has become roughly six times more popular over this interval.
Messaging can have serious consequences. Word choice can have serious consequences. I generally try to use global warming — unless, that is, I’m writing about climate change!