The Climate Change Debate
Climate change is a bigger issue than ever, with Al Gore testifying before Congress last week that we face a civilization-threatening crisis. Climate change is outside ACSH's official bailiwick (and is not a topic on which we have commissioned a peer-reviewed study), but the subject has, of course, raised charges of both unscientific hype and genuine, potentially devastating consequences for human health. Here, two physics-trained, math-savvy, educated-layman observers, without political or institutional axes to grind, take a look at some of the pro's and con's of climate change concern.
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Debate, What Debate?
By Mitchell E. Golden, Ph.D.
Hmm, I'm asked to write a piece for HealthFactsAndFears about climate change. I suppose I could marshal the evidence that global warming is real, that it's caused by human emissions of greenhouse gases, and that it will raise the temperature of the earth somewhere between 1.5 and 4 degrees Celsius during this century. Maybe I could throw in a photo of a melting glacier or two.
Nope, not going to do that — there are already lots of resources out there from which an interested layman can learn about the science of climate change.
I mean, if you can learn about climate from the National Center for Atmospheric Research, wouldn't you prefer to do that than read me?
But since we are all here, let me tell you why the greenhouse effect makes sense.
First of all, it's derived from basic physical principles. The earth is hot because it's warmed by the sun, and at night it cools down by radiating to space. Greenhouse gasses lower the ability of the earth to re-emit, and there's no reason to expect that the earth won't heat up. Simple, right? If the earth isn't going to warm up, you'll need a mechanism to explain to explain why not. Unfortunately for us, no one has thought of any.
You see, I am the sort of guy who finds that a very persuasive argument. I have a Ph.D. in theoretical physics. I like it on those occasions when you can actually analyze a problem from first principles, make predictions, and see them come true.
Now, yes, the Earth is a very complicated system. But so are lots of other systems we know a lot about. Like, say, the bond market — lots of my friends who have the same sorts of Ph.D.s I do are off working on that (and they make much more money than I do, unfortunately). The bond market has millions of human actors — which are much more complicated to model than infrared radiation. But by building proper models you get to make lots of predictions that work.
Now look, I'm not a climate expert. I read about it a lot. But I have a day job, just like everyone else. Since I'm not really an expert, I can't say that I've read the code of the Goddard Institute for Space Studies climate model or that I havelooked into the details of cloud formation. Like everyone else, I have to depend at least partially on the people who really are experts — they're the ones who have hashed all of this out in the peer-reviewed literature.
Here's a partial list of organizations that have made official statements supporting the conclusion that climate change is real and that it's largely caused by human-generated greenhouse gases:
• American Association for the Advancement of Science
• American Meteorological Society
• The Academies of Science of Brazil, Canada, China, France, German, India, Italy, Japan, Russia, UK and US (joint statement)
• The Academies of Science of Australia, Belgium, Brazil, Canada, Caribbean states, China, France, Germany, India, Indonesia, Ireland, Italy, Malaysia, New Zealand, Sweden, and UK (joint statement)
Not to mention a parade of reports written by impartial scientists in the National Academy of Sciences going all the way back to 1979 — long before this was a political issue. And there'a the well-known Intergovernmental Panel on Climate Change Report.
But I know scientists — I used to hang with scientists. They'll bicker over everything. Surely those scientific professional organizations must be riven by controversy, splitting into factions over this very important contemporary issue. But no, I haven't heard about any mass resignations. That's because, among scientists, this isn't actually controversial.
Again, I'm not an expert in climate science. But then, neither is the guy writing the article on the other side of this HealthFactsAndFears debate. And frankly, neither are most of the people writing about it — no, not Al Gore either. I hear lots of silly stuff said about climate. But because I have a technical background, I can at least go look up the primary sources and see what they actually say. And when I do, the stuff I hear from the climate "skeptics" in particular seem to crumble to dust under closer examination.
For instance, Richard Lindzen (a scientist who seems to be quoted in virtually every news report) says that there's been "almost no" temperature rise since 1986. Here: go look at the graph of global temperatures. Doesn't his statement just seem tendentious and silly?
Similarly, I'll often hear someone telling a general audience to go read the technical literature, knowing full well that they won't. Like the time John Stossel went on MSNBC's Scarborough Country and implored the audience to read for themselves the June 22, 2006 National Academy report, rather than relying on "the liberal media," because the academy "said they can't rule out that [global warming is caused by] all natural influences." I'm enough of a dweeb to do just that. So I know that, in fact, the report in question wasn't really about what might have caused global warming, and to the extent it briefly touched on the subject its conclusion was the opposite of what Stossel implied: there are "multiple lines of evidence supporting the conclusion that climate warming is occurring in response to human activities."
Here's the thing: many people think that believing in the reality of global warming is an ideological question. It isn't. I'm a dyed-in-the-wool capitalist. I've founded companies, sold them, and made money doing it. I am not a political idealist and don't care whether all the scientific conclusions described above are termed a "crisis" or not — I just want the scientists listened to and policy made in response to what is actually known.
Even the President of Shell Oil says it's "a waste of time to debate" because climate science is settled. It's time to move on. Let's debate something interesting — like what to do about it.
Mitch Golden received his Ph.D. in Theoretical Physics from the University of California at Berkeley in 1988. He held postdocs a the Fermi National Accelerator Laboratory and Boston University, and was a professor of Physics at Harvard. Since 1995, he has worked as an entrepreneur on web technologies. He lives in Manhattan.
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Rumors of Our Climatic Demise Have Been Greatly Exaggerated
By Chuck Blake
Amid much media flurry, the International Panel on Climate Change (IPCC) delivered its fourth summary for policy makers (SPM), the Academy of Motion Pictures Arts and Sciences gave an Oscar to a An Inconvenient Truth, and Gore testified before Congress that the very survival of our civilization is at stake. The media is replete with global climate change horror stories. We are told that the scientific debate is over, that killer storms, heat waves, droughts, and epidemic diseases lie in wait. We are told that the oceans will swallow our cities and tend to hear about climatological records broken when they are broken in the direction of concern. Gore, to mix animal metaphors, portrays polar bears as canaries in a coalmine, stalked by apocalyptic horsemen — signs of what is to come for humans.
Yet the World and American Meteorological Associations refuse to support specific claims on future weather impact, such as storm intensity. Their reluctance owes to the lack of evidence for storm-intensification trends over the twentieth century, though it saw a 1 C rise in temperature, over one third of the projected rise for the twenty-first century. At best, only the North Atlantic seems to show any such relationship, and it is weak in magnitude. Other regions show opposite effects. Unless one delves into technical literature, one never hears that the theory suggests only 3% more force in the tiny fraction of storms that reach their maximum intensity, or that initial studies' implications often resulted from gerrymandering the boundaries of storm categories. (See Curry, Webster, and Holland, Mixing Politics and Science in Testing the Hypothesis That Greenhouse Warming Is causing a Global Increase in Hurricane Intensity, American Meteorological Society, August 2006.)
Beasts and Beastly Storms
Meanwhile, polar bear demographers count many healthy polar bears thriving in warmer climes, their population doubling in the past twenty years. We are barraged by iconic pictures of bears "stranded" on ice in summertime — yet often within safe swimming distance of shore and able to hop off as they like.
Claims about "records" being set often abuse the underlying statistics. On the one hand it may be warmer than it has been in recent years, but on the other it was also warmer a long while ago with no supposed human influence and no ensuing catastrophe. Records of local phenomena can be very misleading. (See Redner and Petersen, Role of Global Warming on the Statistics of Record-breaking Temperatures, Physical Review E, v74, 061-114.)
Paul Reiter, a top French insect and infectious disease contributor, felt the IPCC message about warming-boosted mosquito populations and other disease threats was so skewed from the facts that he had to resign from the IPCC in protest — and threaten legal action to get his name removed. He tells us that mosquitoes are not necessarily more likely to thrive in warmer times: Siberia has had malaria-carrying mosquitoes forever; mosquito-dominated regions are closer to, not farther from, equatorial regions than a hundred years ago; and none of the new diseases Gore talks about can be attributed to warming.
Even using data from the current IPCC report, we see the projections of sea level rise by 2100 are about the same as the non-catastrophic rise from 1850 to present. The same report also can substantiate no net acceleration of net ice loss from a hundred years ago to the present.
What We Don't Know — and Why Science Works
To a quantitative eye, the IPCC's summary for policy makers includes a chart indicating that our ignorance about the influence of man is almost as great as our knowledge. The role of carbon dioxide (CO2), generally assumed to be the cause of our impending overheating, is overplayed because it is better understood. The role of aerosols such as dust is underplayed because it is poorly understood — though it is about as large as that of CO2 and in the opposite direction. Historically, atmospheric CO2 tends to rise centuries _after_ temperatures rise, and there have been epochs with an order of magnitude more CO2 during ice ages. In general, in the climate change debate as shaped by IPCC, qualitative accounts ("bad things will happen") are poorly supported by the underlying quantitative tables.
Science is better than myth-telling because science's future predictions acquire credibility in proportion to the fulfillment of past predictions. Quantitative science on complex, poorly understood systems requires special cautions. We surely require pharmacologists to use proper double-blind clinical trials rather than just trusting anecdotal evaluations or theoretical blood chemistry beliefs. We don't believe stock market forecasters who lose money. In climate science, a handful of weak, qualitative predictions are often presented as the fruits of a mature, reliable science, while a half dozen unresolved deep issues and poor quantitative confirmation are ignored.
See, for example, the main IPCC Working Group I chapters when they are released or the 2006 paper by Hansen, Sato, et al., for the National Academy of Sciences. Though alarmist in tone, Hansen admits that the agreement of his 1988 climate prediction models with later data was "accidental," that seventeen years is too brief a time to quantitatively validate the model, and that it is likely to prove wrong anyway. Climate scientists are fond of saying projecting climate is different from weather — climate is like predicting average rainfall, not rain tomorrow. How then should we take climatologists' self-acknowledged failure to accurately predict even regional climate or anything close to average precipitation? Or their failure to foresee the cooling of the oceans during 2003-2005, the largest oceanic cooling event in decades? (See Lyman, Willis, and Johnson, Recent Cooling of the Upper Ocean, Geophysical Research Letters, September 2006.)
Hawking-class physicist Freeman Dyson is a long-time critic of presumed model-reliability, saying they use fudge factors for important processes.
Fear Not
Even if models were reliable, there is no clear cause for fright. Consensus for slightly elevated temperatures and vague causation is misrepresented as consensus for alarm. More and more climate scientists are feeling the need to back away from the unrealistic histrionics of politicians and the media. As Mike Hulme, director of Britain's Tyndall Center for Climate Change Research said: "It seems that it is we, the professional climate scientists, who are now the (catastrophe) skeptics."
There is some hope, though, that the public is developing a thick skin with regard to exaggerated claims. After a little persuasion by Michael Crichton, Richard Lindzen, and Philip Stott at a recent debate hosted by Intelligence Squared in Manhattan, skepticism about an impending crisis won majority support from an audience that had initially self-identified as being mostly believers in a man-made climate crisis. That audience's change in opinion could be the real harbinger of things to come.
Chuck Blake, trained in physics at CalTech and UCSD and formerly on the MIT computer science faculty, is now doing statistical modeling in the financial sector. In February, he argued the "skeptic" position on catastrophic climate change at one of the monthly debates hosted in Manhattan by HealthFactsAndFears editor Todd Seavey (in a non-ACSH capacity).
