Global Warming

Are Antarctic Temperatures Warming or Cooling?

| by Cato Institute

Just about every major outlet has jumped on the news: Antarctica is warming up.

Most previous science had indicated that, despite a warming of global temperatures, readings from Antarctica were either staying the same or even going down.

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The problem with Antarctic temperature measurement is that all but three longstanding weather stations are on or very near the coast. Antarctica is a big place, about one-and-a-half times the size of the US. Imagine trying to infer our national temperature only with stations along the Atlantic and Pacific coasts, plus three others in the interior.

Eric Steig, from University of Washington, filled in the huge blanks by correlating satellite-measured temperatures with the largely coastal Antarctic network and then creating inland temperatures based upon the relationship between the satellite and the sparse observations. The result was a slight warming trend, but mainly at the beginning of the record in the 1950s and 1960s. One would expect greenhouse effect warming from carbon dioxide to be more pronounced in recent years, which it is not.

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There's actually very little that is new here. Antarctic temperatures do show a warming trend if you begin your study between 1957, when the International Geophysical Year deployed the first network of thermometers there, and the mid-1960s. Studies that start after then find either cooling or no change.

Steig and his colleagues didn't graph the data for the continent as a whole. Instead they broke it into two pieces: the east and west Antarctic ice sheet regions. A naïve reader would give equal weight to both. In fact, in the east, which is much larger, there is clearly no significant warming in the last several decades. When the results are combined, the same old result reappears, namely that the "warming" is driven by years very early in the record, and that the net change since the early 1970s is insignificant.

The reaction to this study by Steig and his co-authors is more enlightening than its results. When Antarctica was cooling, some climate scientists said that was consistent with computer models for global warming. When a new study, such as Steig's, says it's warming, well that's just fine with the models, too. That's right: people glibly relate both warming and cooling of the frigid continent to human-induced climate change.

Perhaps the most prominent place to see how climatologists mix their science with their opinions is a blog called, primarily run by Gavin Schmidt, one of the computer jockeys for Nasa's James Hansen, the world's loudest climate alarmist.

When studies were published showing a net cooling in recent decades, RealClimate had no problem. A 12 February 2008 post noted: "We often hear people remarking that parts of Antarctica are getting colder, and indeed the ice pack in the southern ocean around Antarctica has actually been getting bigger. Doesn't this contradict the calculations that greenhouse gases are warming the globe? Not at all, because a cold Antarctica is just what calculations predict ... and have predicted for the past quarter century."

A co-author of Steig's paper (and frequent blogger on RealClimate), Penn State's Michael Mann, turned a 180 on Antarctic cooling. He told Associated Press: "Now we can say: No, it's not true. ... [Antarctica] is not bucking the trend."

So, Antarctic cooling and warming are both now consistent with computer models of dreaded global warming caused by humans.

In reality, the warming is largely at the beginning of the record — before there should have been much human-induced climate change. New claims that both warming and cooling of the same place are consistent with forecasts isn't going to help the credibility of climate science, and, or reduce the fatigue of Americans regarding global warming.

Have climate alarmists beaten global warming to death? The Pew Research Centre recently asked over 1,500 people to rank 20 issues in order of priority. Global warming came in dead last.

We can never run the experiment to see if indeed it is the constant hyping of this issue that has sent it to the bottom of the priority ladder. But, as long as scientists blog on that both warming and cooling of the coldest place on earth is consistent with their computer models, why should anyone believe them?