The Fourth Assessment Report from the Intergovern-mental Panel on Climate Change contains over 900 pages. And that’s only the section that outlines the physical science basis of global warming. If you haven’t yet done so, when you get around to evaluating the IPCC’s scientific claims, don’t forget to check the citations as well.
The abridged version of this Fourth Assessment Report given in many mainstream media sources, that global warming is “unequivocal” and has “very likely” been enhanced by human activity in the last 50 years, is easy enough to swallow. Do we really need to check the sources? Even if you don’t take Al Gore’s word as gospel or sing in the liberal choir, the IPCC’s confident claims about global warming are based on decades of climate science compiled from scores of researchers. And the IPCC wouldn’t distort science with a political agenda, would it?
As a person with little background in science, I struggle with how to evaluate global warming claims. Setting aside the heresy of global warming denial, it would be poor thinking to take at face value such extreme, earth-shattering statements made by a former politician and the media without probing them at all. But how does a person like me, unfamiliar with climate science, go about judging these statements? And lacking perfect knowledge about how to do so, how does one follow out the clear call to care for the environment?
Since the IPCC seems to have the authority to say whether global warming is something to be concerned about or not, the least I can do is read what it has to say about it. The physical science explanations in the Working Group 1 section of the Fourth Assessment Report are relatively simple to follow. But even if I read the entire 900-page report and understand in scientific terms what it is telling me, it doesn’t necessarily follow that the report is founded on good science. And unless I learn more about climate science, I have no way of knowing.
But why not accept the global warming hypothesis on authority, if there is really the consensus among scientists that Al Gore claims? Scholarly articles abound that either take global warming for granted or provide new evidence for it, but there are some that challenge certain aspects of the theory.
The most troubling criticism of the IPCC’s work that I have read questions the accuracy and predictive ability of current mathematical climate models. In a March 21 presentation by Canadian climatologist Tim Ball, available on the George C. Marshall Institute Web site, Ball argues that the models used to simulate the entire climate are too simplistic to accurately map its chaotic and complex phenomena. “They are an extremely cloudy crystal ball and they oversimplify poorly-understood climate processes, for example, precipitation and transport of energy,” Ball says. If you know something about climate models, you may read Ball’s critique and find obvious flaws. But to the non-scientist, his presentation is just as compelling as the IPCC’s.
Ball’s flame is only fanned by the Geophysical Fluid Dynamics Laboratory (GFDL), whose climate models are used in the Fourth Assessment Report. An article on the GFDL Web site entitled “Why Climate Models are Imperfect and Why they are Crucial Anyway” acknowledges their over-simplicity and excuses it by saying they are better than they used to be, and that there “is no viable alternative” for predicting future climate conditions. Even as a layman, this defense is unsatisfying.
So should I ignore fringe critiques like Tim Ball’s? Sourcewatch.org says that Ball has worked for the Natural Resources Stewardship Project, which is allegedly controlled by energy industry lobbyists, and Friends of Science, which has received funding from oil companies. Even if these connections discredit Ball’s research, it would again be sloppy thinking to assume that any critique of climate models is funded by oil companies and therefore preemptively dismiss it. In any scientific statement either supporting or critiquing global warming, the bottom line should be the science itself, not who presents it or how many people agree with it.
But as far as the layman is concerned, consensus and connections do matter. If I’m not going to study climatology, I have to keep looking for agenda-free climatologists to explain the science to me, and, if that is possible, it may be the best I can do.
The worst thing I could do would be to act as if science is the only source of information about how to care for the environment and seize on the vestiges of “uncertainty” as an excuse for inaction. Our relationship to the environment is what is really at stake in the discourse about global warming and our responsibility to care for it is not up for debate. If you aren’t completely sure that environmental responsibility means cutting carbon emissions, it’s time to follow out what it does mean.