Cass R. Sunstein is a professor at the Harvard Law School and a former administrator of the Obama White House Office of Information and Regulatory Affairs. His op-ed in the NY Times (Nov 11, 2012) tells us that a cost-benefit analysis convinced President Reagan of the value of the 1987 Montreal Protocol (to control substances that deplete the stratospheric ozone layer).

Sunstein then admonishes Republican lawmakers to apply Reagan’s lesson to global warming and CO2. But he seems to have forgotten his own published paper “Of Montreal and Kyoto: A Tale of two Protocols” (Harvard Environmental Law Rev 2007) in which he quite clearly explained why Kyoto does not work, one reason being that costs are huge and benefits small. But even Sunstein’s historical account is challenged in a guest post by Reiner Grundmann, a professor of Science & Technology Studies at the University of Nottingham.

According to Sunstein, Reagan evidently trusted and accepted the numbers he was given by his economic advisors. But he certainly didn’t verify them. Had he done so he might not have been as quick in his support as Sunstein suggests. The moral of the story: Cost-benefit analysis is fine, but the numbers must be supported by sound science. Note that chief US negotiator Richard Benedick recounts (with obvious pride) in his book Ozone Diplomacy, that the Montreal Protocol was negotiated without the benefit of any support from science.

The Antarctic Ozone Hole

In reality, the drive for Montreal was propelled by panic generated by lurid newspaper accounts of possible health consequences from the Antarctic Ozone Hole (AOH), which was discovered in 1985. Having personally devised the satellite instrument that tracked the AOH, I remember well the scary accounts of blind sheep in Patagonia—with suggestions that people living in the southern hemisphere would be similarly affected.

It is ironic that the AOH was never predicted but discovered by serendipitous observations. The original mechanism for ozone destruction discussed by the late Sherwood Rowland and Mario Molina applied only to the upper stratosphere, where there is very little ozone—and is therefore of little practical significance. A more complicated mechanism apparently operates in the lower stratosphere where most of the ozone is concentrated; it was worked out only after the AOH discovery. It still involves chlorine as the agent for ozone destruction, but it also requires the presence of particulates in the stratosphere.

It is worth noting that at the time of the Montreal Protocol, published evidence did not indicate a detectable human contribution to stratospheric chlorine. It had been known that long-lived CFCs (chlorofluorocarbons, with a lifetime of a century or so) could reach the stratosphere. After all, there was an observed increase in fluorine, but there was no corresponding increase in chlorine. If there had been an important contribution from anthropogenic CFCs, one should have seen a gradual increase in the concentration of stratospheric chlorine. But that was only established some years after Montreal when NASA scientist Curtis Rinsland repeated some of the crucial measurements and found a quite different result. Up until then, it had seemed that natural sources would swamp any chlorine contributed from CFCs. In fact, the expert opinion of Professor Rowland was that the (natural) contribution to stratospheric chlorine could be ignored—that from ocean salt spray would be less than 1 part per 10,000—a claim nearly impossible to verify.

So President Reagan missed the chance to verify the benefits numbers he got from his economic team. He should have noticed, however, that despite the measured increase in CFCs there was no corresponding increase in solar ultraviolet radiation at the earth’s surface - as a consequence of possible ozone depletion. (Solar UV-B is the presumed agent that causes skin cancer.)

Fast forward to the Bush (41) administration: Premature reports of an incipient Arctic ozone hole (the notorious “Hole over Kennebunkport” that never existed) threw George Bush into a panic and caused him to advance the US phase-out date of CFCs by five years—at great expense. On the other hand, China will be the last country required to phase out CFCs—by 2016. Meanwhile, the rest of the world has switched to HFCs; they won’t deplete ozone, but they are global-warming gases which will face controls in the near future.

Skin Cancer Facts

Another fast forward—to the Clinton administration: One of the hot issues then was the possible ban on Methyl Bromide (MeBr), an extremely important agricultural chemical, used as a fumigant to preserve stored grain from all sorts of spoilage and pests. It became a ’cause celebre’ for environmental zealots who wanted to ban every possible agent that might destroy stratospheric ozone. Yet MeBr is very different from CFCs. Most of it originates from natural sources rather than from manufacture. Its atmospheric lifetime is only a few months rather than a century or so; it really is doubtful if it lasts long enough to reach the stratosphere. In any case, there was no measurement showing a stratospheric increase in bromine compounds. So again, no scientific evidence of a human contribution—and no effort to verify.

A key factor in phasing out MeBr was testimony by EPA assistant administrator Mary Nichols. (Yes, this is the same Mary Nichols who now heads the powerful California Air Resources Board). She told a hearing chaired by Congressman John Doolittle (R-CA) that the benefits of phasing out MeBr would be 32 trillion dollars—an incredible sum of money in the 1990s when even a billion dollars was real money.

Now it turns out that she got those numbers from a trusted (activist) economist in the Clinton White House, but of course she didn’t verify. If she had, she would have found that the serious form of skin cancer, malignant melanoma, seems to be caused mainly by solar UV-A radiation, rather than UV-B. (All this was established in experiments by Richard Setlow at Brookhaven National Lab; in fact, recent research indicates that melanoma may develop without any solar radiation.) And since UV-A is not absorbed by ozone at all, efforts to protect the ozone layer would not protect against melanoma.

Prof. Sunstein tries to extrapolate the lesson from Montreal (as he sees it) to the Kyoto Protocol and to global warming. I agree with him that cost-benefit analysis is a wonderful tool, but it has to be verified by proper science. When we do that, we will find that all of the current efforts to eliminate the greenhouse-gas carbon dioxide are pointless, extremely expensive—and counterproductive.