Headlines are meant to sell papers, but the above scream from atop Page 1 of today’s Houston Chronicle deserves critical comment. A fair and accurate (but less sexy) headline would have been: “EPA Declares Peril of Greenhouse Gases.” Just changing one word–from “recognizes” to “declares”–makes all the difference.
The Chronicle, particularly the editorial page, has been a bastion of climate alarmism rather than informed skepticism, or what a lot of us simply call climate realism. (Eric Berger, the “sci-guy” at the Chronicle, is more of a straight shooter on day-to-day global-warming reporting.)
The science is not settled in favor of climate alarmism. But this conclusion requires some background and explanation.
According to the United Nation’s Intergovernmental Panel on Climate Change (IPCC), the warming from an equilibrium doubling of atmospheric concentrations of carbon dioxide (CO2) and other man-made greenhouse gases (GHG) is between 2C and 4.5C (multiply by 1.6x for Fahrenheit). This is a lot of warming, and the models behind these predictions make very strong assumptions about feedback effects than are in dispute. In short, the model driver is that feedback effects double or triple the base warming (of about 1C).
With very little warming in the last 10–15 years, the IPCC projections from the 2007 report are on the edge of being out-of-bounds. As Chip Knappenberger has posted:
Depending on which global surface temperature dataset you use, the observed trend during the past 96 months lies very near the low side of the 95% confidence range of the collection of climate model projections.
What this means, is that the observed rate of global temperature change has been quite slow during this time, and while perhaps not totally unprecedented in the realm of model projections, at the very least, it is starting to become pretty unusual.
If a pronounced warming does not resume, then all eyes will turn to the exciting feedback work of Roy Spencer and Richard Lindzen. To a lot of people, this is where the action is. And such feedback research shows promise of being not good but wonderful for mankind.
But back to the IPCC warming estimate. At the low end of the (teetering) IPCC range, the warming may well have more positive externalities than negative ones, according to Robert Mendelsohn, a well-regarded, even mainstream, environmental economist at Yale University. In other words, the human influence on climate is good on net, not bad, and EPA and government institutions worldwide do not need to regulate GHG emissions.
Is 2C a better estimate than 4.5C or even the best-guess of 3C? Given the data, you bet it is! And some leading climatologists from even the alarmist camp quietly believe it is too. One such person I know well personally: Gerald North, Distinguished Professor of Atmospheric Sciences and Oceanography at Texas A&M University (and the 2008 recipient of the Jule Charney Award of the American Meteorological Society). As I previously posted:
Even members of the “mainstream” disagree with [James] Hansen [‘s high-sensitivity warming estimate]. For example, Gerald North at Texas A&M has projected 2C for as long as I have known him. Not that his self-described “toy model” is definitive, but intuition from seasoned veterans like North might well be better than climate models that are problematic, as the IPCC itself admits: “The set of available models may share fundamental inadequacies, the effects of which cannot be quantified,” p. 805.
So back to the Chronicle headline. EPA did not “recognize” objective reality of a human peril from anthropogenic greenhouse gas emissions. The agency declared the threat to be so. Those are two very different things.
Let this 21-year political debate continue, and may minds be open to change on the theory of climate change, including minds at the Houston Chronicle. There is a happy middle in this debate.