|Above: A portion of NASA's iconic Blue Marble satellite image of Earth. Image credit: NASA.|
During an interview with journalist Piers Morgan that aired Sunday on Britain’s ITV network, U.S. President Donald Trump brought up a meme used often by those who deny climate change. It’s a talking point that deserves a proper burial. Trump said:
"There is a cooling, and there’s a heating. I mean, look, it used to not be climate change, it used to be global warming. That wasn’t working too well because it was getting too cold all over the place.”
The history of the phrases “climate change” and “global warming” is much more interesting than Trump gives it credit for. Researchers were using climatic change or climate change as far back as the early 20th century when writing about events such as ice ages. Both terms can describe past, present, or future shifts—both natural and human-produced—on global, regional, or local scales.
The prestigious journal Climatic Change debuted in 1977, belying Trump’s claim that “it used to not be climate change.”
|Figure 1. The first two articles from the first issue of the journal Climatic Change (March 1977). Image credit: Courtesy SpringerLink, Springer Publishing.|
By the 1970s, scientists were becoming increasingly concerned about the threat of climate change arising from human-produced greenhouse gases. Global temperatures had been relatively flat since the 1940s, and several intense cold waves and snowstorms in North America and Europe grabbed public attention in the 1970s. A few scientists worried that the post-war growth of sun-blocking pollutants could push Earth toward the possibility of a new ice age, as covered in TIME (1974) and Newsweek (1975). Thomas Peterson (NOAA/NCEI) later showed that the vast majority of peer-reviewed research on climate change published in the 1970s was more concerned about the longer-term warming threat from fossil fuels than about global cooling.
In 1975, Wallace Broecker (Lamont-Doherty Earth Observatory) published a paper in the journal Science titled “Climatic change: Are we on the brink of a pronounced global warming?” This appears to have been the first use of “global warming” in a paper title, and it caught on.
By the early 1980s, the phrase global warming was gaining currency among scientists. Journalists tended to invoke the term greenhouse effect (often in quotes) as a stand-in phrase for human-produced warming. Meanwhile, the terms global change and global climate change emerged as a way to embrace all modes of large-scale tampering with the planet, including such emerging issues as the Antarctic ozone hole.
“Global warming” finally became a household phrase in 1988, when severe drought and wildfires plagued the United States and NASA’s James Hansen made his historic statement before Congress on June 23 (full text here): “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.”
|Figure 2. Dr. James Hansen testifies before Congress on June 23, 1988. Image credit: NASA, via elephantpodcast.org.|
The term “climate change” never went away or came back, though. The Intergovernmental Panel on Climate Change (IPCC) has been called just that ever since it was established in 1988. Many scientists have long preferred “climate change” over “global warming” to describe our current predicament. For example:
• “Global warming” could be interpreted as a uniform effect—an equal warming everywhere on the planet—whereas there will be regional variations in the rate of long-term warming. Some regions could experience periods of little warming or even slight cooling, while others (such as the Arctic) are warming more quickly than the global average.
• “Global warming” fails to convey that changes to precipitation—the heaviest rain events becoming heavier, drought impacts getting worse—can be more problematic in some areas than a temperature rise in itself.
There was in fact another push away from “global warming”—a recommendation from a U.S. consultant, Frank Luntz, that was intended to help Republican politicians soft-pedal the issue. Based on focus-group research, Luntz published a memo in 2001 (linked from desmogblog.com) asserting that “climate change” sounded less frightening to the lay ear than “global warming.”
|Figure 3. This photo, taken during the NASA ICESCAPE mission in summer 2011, shows melt ponds on the surface of Arctic sea ice. Weather patterns in the Arctic favored ice loss, leading to near-record low ice extent over most of the summer. Image credit: NASA/Kathryn Hansen, via NSIDC.|
Polar ice is not increasing
In his ITV interview, Trump also claimed:
“The ice caps were going to melt, they were going to be gone by now, but now they’re setting records. They’re at a record level.”
It’s not clear whether Trump was referring to sea ice or to the ice sheets atop Greenland and Antarctica, but the point is moot: ice is on the decline across the globe. “Both of the large ice sheets of Greenland and Antarctica are losing hundreds of billions of tons of ice per year,” Michael Oppenheimer (Princeton University) told the Associated Press.
Sea ice builds and melts every year with the waxing and waning of the seasons. The amount of sea ice that persists from year to year in the Arctic Ocean has declined dramatically, and the trend in the minimum summer extent has been downward for decades, with some sharp year-to-year variations. As of January 28, the extent of Arctic sea ice was at its lowest level for the date in satellite records going back to 1978.
Sea ice around Antarctica actually held its own for years, even increasing slightly (a fascinating story in itself). But in 2016 it plummeted to record-low extents and has recovered only slightly since then.
And as of late January 2018, the global total of sea ice was close to the lowest level measured since satellite observations began in 1978 (see Figure 4 below).
In short, across land and sea, there’s just no way to justify a claim that ice caps are “at a record level"—unless one means “record low level.”
|Figure 4. Global sea ice extent, combining values from the Arctic and Antarctic. Because there is a far larger annual swing from minimum to maximum ice in the Antarctic, that region’s seasonal cycle dominates the global graph. Ice growth and decay is independent in the two regions, but the combined total has dropped noticeably over the last two years. The global total of sea ice extent as of Jan. 28, 2018 (bright red line) is close to the lowest value measured on any date since satellite records began in 1978. Image credit and documentation: Wipneus.|