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.”
On Sunday, in anticipation of Sen. Ted Cruz’s (R-TX) announcement that he intends to run for president, California governor Jerry Brown (D), declared to NBC’s Meet the Press Cruz was “absolutely unfit to be running for office.” Why? Because of Cruz’s stance on climate change—some of which Cruz laid out on late night TV last week.
But comparing Cruz’s comments on Late Night with Seth Meyers and Brown’s remarks on Meet the Press, it is pretty clear that it is Gov. Brown who needs to spend more time familiarizing himself with the scientific literature on climate change and especially its associations with extreme weather events.
Apparently Gov. Brown is convinced that climate change, or rather the apparently scarier-sounding “climate disruption” Brown prefers, is behind the ongoing drought in California, not to mention the East Coast’s cold and snowy winter.
Cruz, on the other hand, told a more restrained story—that data doesn’t support many alarmist claims and that satellites show no warming during the past 17 years while climate models expected warming—one which comports better with the science that he portrayed.
While there is certainly more to the story than Cruz went into in his brief appearance with Seth Meyers, he is right, that according to satellite observations of the earth’s lower atmosphere as compiled by researchers at Remote Sensing Systems, there has been no overall temperature increase during the past 17 years.
Gov. Brown, meanwhile, decided to elaborate on the climate change issue. Under general questioning from Meet the Press host Chuck Todd, Brown admitted that is was difficult to link specific events, like the California drought, to human-caused climate change. But then Todd played a snippet of Cruz’s Late Night interview where Cruz said:
And my view actually is simple. Debates on this should follow science and should follow data and many of the alarmists on global warming, they have a problem because the science doesn’t back them up.
Brown’s assertions then got much bolder:
What [Cruz] said is absolutely false. Over 90% of the scientists who deal with climate are absolutely convinced that the human activity, the industrial activity, the generation of CO2, methane, oxides of nitrogen and all the rest of those greenhouse gases are building up in the atmosphere, they are heat-trapping, and they are causing warming, not just drought in California, but severe storms and cold in the East Coast. So it’s climate disruption of many different kinds. And that man betokens such a level of ignorance and a direct falsification of existing scientific data. It is shocking, and I think that man has rendered himself absolutely unfit to be running for office.
Unfortunately for Brown, it is he that is speaking against "existing scientific data."
Consider this new study by a team led by Geophysical Fluid Dynamic Laboratory’s (GFDL) Thomas Delworth that examined the association between the global warming hiatus and drought in western North America (including California). Turns out, according to these scientists, both stemmed from a similar cause—a change in the patterns of winds across the tropical Pacific Ocean. Further, they suggest this pattern was not overly consistent with expectations from human-caused climate change. Here is an excerpt from that paper:
The strong connection between the intensification of Pacific trades and the drying in western North America observed over the past decade suggests that this drying cannot be connected in a straightforward fashion to greenhouse gas increases. In most coupled [climate model] simulations anthropogenic forcing produces a long-term weakening of the Walker circulation and tropical Pacific trade winds, but with substantial intrinsically-generated variability on decadal scales (Vecchi et al. 2006). Therefore, unless it can be shown that the strengthened trade winds are a result of either natural or human-induced radiative forcing changes, the model results suggest that the observed drying over the western U.S. over the last decade may be primarily due to natural variability, and therefore not necessarily a harbinger of a secular drying trend (Hoerling et al. 2010; Seager and Naik 2012). These results highlight how vulnerable western North America is to severe decadal swings in hydroclimate arising from internal variations of the climate system.
Clearly, Gov. Brown is out of touch with these findings, just as he is with many findings on East Coast cold and snow (for example, here, here, and here). But this is typical of those who are intent on attacking those folks (politicians, scientists, writers, etc.) who take a dimmer view than themselves on the necessity for policy action aimed to combat climate change—policies which too often seek to limit energy choice.
If anyone is keeping score, this round of political squabbling over climate change should go to Sen. Cruz.
Delworth, T.L., et al., 2015. A link between the hiatus in global warming and North American drought. Journal of Climate, doi:10.1175/JCLI-D-14-00616.1, in press.