Temperature Trends

Climatologist John Christy: "The Science Is Not Settled"


John Christy
Huntsville Times

The New York Times is running a pretty fair profile of University of Alabama in Huntsville (UAH) climatologist John Christy today. As Reason readers know, I blog every month the global satellite temperature trend produced by Christy and his UAH colleague Roy Spencer. I have relied on Christy as a source of honest data and insight ever since I began reporting on the science and policy issues related to man-made global warming over two decades ago. Based on empirical temperature data he has long questioned the computer climate model projections of rapid and dangerous warming, which has gained him no friends in what he calls "the climate establishment."

From the Times:

John Christy, a professor of atmospheric science at the University of Alabama in Huntsville, says he remembers the morning he spotted a well-known colleague at a gathering of climate experts.

"I walked over and held out my hand to greet him," Dr. Christy recalled. "He looked me in the eye, and he said, 'No.' I said, 'Come on, shake hands with me.' And he said, 'No.' "

Dr. Christy is an outlier on what the vast majority of his colleagues consider to be a matter of consensus: that global warming is both settled science and a dire threat. He regards it as neither. Not that the earth is not heating up. It is, he says, and carbon dioxide spewed from power plants, automobiles and other sources is at least partly responsible.

But in speeches, congressional testimony and peer-reviewed articles in scientific journals, he argues that predictions of future warming have been greatly overstated and that humans have weathered warmer stretches without perishing. Dr. Christy's willingness to publicize his views, often strongly, has also hurt his standing among scientists who tend to be suspicious of those with high profiles. His frequent appearances on Capitol Hill have almost always been at the request of Republican legislators opposed to addressing climate change.

"I detest words like 'contrarian' and 'denier,' " he said. "I'm a data-driven climate scientist. Every time I hear that phrase, 'The science is settled,' I say I can easily demonstrate that that is false, because this is the climate — right here. The science is not settled."

Dr. Christy was pointing to a chart comparing seven computer projections of global atmospheric temperatures based on measurements taken by satellites and weather balloons. The projections traced a sharp upward slope; the actual measurements, however, ticked up only slightly.

Such charts — there are others, sometimes less dramatic but more or less accepted by the large majority of climate scientists — are the essence of the divide between that group on one side and Dr. Christy and a handful of other respected scientists on the other.

It would have been helpful if the Times had actually published one of his charts showing the divergence between actual global temperature trends and computer model projections. Here's one such:


And being suspicious of those with high profiles? Oh, please. Do not leading consensusers James Hansen, Michael Mann, John Holdren, Kerry Emanuel, and so forth have "high profiles" when it comes to climate science? As reported by numerous newspapers including the New York Times, James Hansen famously testified before a Congressional committee way back in 1988 that "global warming has begun."