July 11, 2014 4:25PM

Influencing Climate Policy on the Back of a Lame Horse

Global Science Report is a feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”


While we hate to beat a dead horse, despite our best efforts, it’s apparently still alive and kicking.

It is a horse called “Global Warmed Causes Cold Winters and Therefore We Should Regulate Carbon Dioxide Emissions” and proudly jockeyed by White House science adviser John Holdren. (It is rumored that the horse was sired by “Comply or Die,” the winner of the 2008 Grand National Steeplechase and a favorite among the global warming alarmist crowd.)

Previously, on several occasions, we have pointed out that  Holdren’s view that greenhouse gas-induced climate changes lead to more frequent cold outbreaks (as espoused in this YouTube video produced by the White House during last winter’s frigid cold) is a (dwindling) minority viewpoint. Leading researchers on the topic have made a special point of declaring that the hypothesis is rather unlikely. 

In recent months, new research, in part inspired by last winter’s “polar vortex” excursion southward into the eastern United States,  and the White House-spurred speculation that it was caused by anthropogenic climate change, has hit the scientific press. In each case,  new research has found little evidence in support of Holdren’s contention and a rather lot of evidence to the contrary.

In fact, so much evidence has built up against Holdren that the good folks over at the Competitive Enterprise Institute (CEI) filed a formal request for correction with the White House Office of Science and Technology Policy under what’s known as the federal Data Quality Act.

The CEI petition was, predictably, denied, with the claim that the information in the video did not violate the Data Quality Act because the video only reflected Holdren’s “personal opinion,” not a “comprehensive review of the scientific literature.”

Amen to the latter! But the problem—and a troubling problem at that—is that Holdren’s “personal opinion” carries a lot of weight in the White House and influences federal policy.

For example, in announcing proposed regulations limiting carbon dioxide emissions from existing power plants, EPA Administrator Gina McCarthy said “I’m tired of people pointing to the Polar Vortex as a reason not to act on climate. It’s exactly the opposite. Climate change heightens risks from extreme cold that freezes power grids.”

More evidence of Holdren’s influence is found in this New York Times’ article from last week “Obama Adviser on Front Lines of Climate Fight: John Holdren’s Influence Seen in Obama’s Policies.” According to the Times’ article:

But it also acknowledged a truth: Mr. Holdren has this president’s ear, perhaps more than any White House science adviser in recent memory, at a time when climate change has been thrust to the forefront of national politics and could help shape Mr. Obama’s legacy.

Mr. Holdren’s influence can be seen in many of the administration’s policies, including its biggest on climate change—the plan to cut power plant emissions of carbon dioxide, the main contributor to global warming.

“John was right at the heart” of the deliberations, said the White House chief of staff, Denis R. McDonough.

The topic of Holdren’s views on  global warming, cold outbreaks, and the CEI petition was briefly raised in the article, with little concession by the White House.

In fact, among climate scientists the issue of a link between Arctic warming and cold spells is still far from resolved. The White House Office of Science and Technology Policy, which Holdren leads, said it stood by the accuracy of the video, but added, “there will be continuing debate about exactly what is happening.”

The "debate about exactly what is happening" is becoming decidedly more one-sided (and not in Holdren’s favor).

A prominent study on the topic appeared in the journal Nature Climate Change last month. The paper was written ny the University of Exeter’s James Screen, who  found that cold winter days were actually warming more than not-so cold winter days—with the net result that climate change was leading to less variability in winter temperatures, not more, as would occur under Holdren’s scenario.

[What was left out of Screen’s paper was acknowledgement that we—Knappenberger and Michaels—published nearly the same result 13 years ago! See here for details.]

Accompanying the Screen article was a piece by Eric Fischer and Reto Knutti that explained how the picture relating climate change to winter cold outbreaks was increasingly coming into focus—and showing that climate change should moderate winter weather, not make it more severe. 

The Fischer and Knutti article contains gems like these:

A number of studies proposed that strong Arctic warming and declining sea ice extent caused the jet stream to meander more, thereby making temperatures more volatile and causing more intense cold spells in mid-latitudes of the northern hemisphere. As he reports in Nature Climate Change, James Screen challenges this hypothesis and provides observational evidence for the opposite effect.


In the end, the most powerful argument is the observational evidence and our quantitative physical understanding. Screen demonstrates that despite recent cold winters, cold days have become less, rather than more, extreme.

and our favorite:

What is robust, however, is that the popular picture of a general "global weirding"—of all kinds of weather becoming more extreme and volatile across the globe—is simplistic and misleading.

It’s long is past time for the White House to come clean on all of this and admit that the global warming/polar vortex horse is lame. Hiding this fact unfairly lowers its odds and risks the placement of misguided bets—for example, President Obama’s Climate Action Plan.

P.S.: Weather forecast models for next week—normally the second-hottest week of the year in the eastern United States—are predicting a jet stream orientation that looks a lot like what dominated last winter (i.e., a return of the dreaded "polar vortex"), and far, far below-normal temperatures, especially in the Midwest. We doubt people will mind as much as they did in January and therefore doubt that the White House will declare that the cool (and welcomed) summer weather is "consistent with" anthropogenic global warming.


Fischer, E. amd R. Knutti, 2014. Heated debate on cold weather. Nature Climate Change, 4, 537-538.

Knappenberger, P.C., P.J. Michaels, and R.E. Davis, 2001. Nature of observed temperature changes across the United States during the 20th century. Climate Research, 17, 45-53.

Screen, J., 2014. Arctic amplification decreases temperature variance in northern mid- to high-latitudes.  Nature Climate Change, 4, 577–582.