Methane Regulation: Some Personal Recollections

See also: Methane Madness: Science Does Not Support White House Policy

The White House-EPA plan to control methane emissions is but the latest effort against our domestic energy industry and would simply raise costs to consumers.  It acts like an energy tax, but with no money flowing into the US Treasury – a pure waste of resources.  EPA is apparently unaware that the generally believed greenhouse (GH) effectiveness of methane (when compared to a molecule of CO2) is too high by a factor of about 100.  In addition, atmospheric methane levels are roughly 200 times less than those of CO2 – yielding a GH overestimate of about 20,000.  This display of recent scientific ignorance has brought back memories of 45 years ago.

My involvement with methane began in 1970 while I was serving as deputy assistant secretary in the US Department of Interior.  One day, the FAA asked me to chair a technical panel to evaluate the possible effects on stratospheric ozone of two Supersonic Transport (SST) prototypes then under construction at Boeing. 

SSTs, Ozone Depletion, and Skin Cancer

Real opposition to the SST prototypes came from environmental groups that feared the possible effects of an eventual commercial fleet of 500 SSTs.  Their concern was that water vapor created in jet-fuel burning would destroy some of the ozone residing in the normally super-dry stratosphere.  (Several years later it was discovered that nitrogen oxides, also created in SSTs from high-temperature burning, would be more effective depleters of ozone.)  Such a thinning of the ozone layer would permit more solar ultra-violet (UV) radiation to reach the surface and thereby increase the rate of skin cancers.

This SST-cancer scenario had been proposed by William McDonald, a professor at the University of Arizona.  The cause had been taken up enthusiastically by many environmentalist groups, including the Union of Concerned Scientists (UCS).  McDonald had a poor reputation since he also had a well-publicized belief in UFOs.  Nevertheless, I thought he was mostly correct in his analysis of the UV-Skin Cancer hazard.  [Tragically, McDonald committed suicide shortly after.]

I never believed in the commercial viability of the SST, and doubted that a fleet of 500 planes would ever be constructed.  Because of its sonic boom, it would not be allowed to fly over the continental United States at supersonic speeds, so its use was limited to intercontinental flights.  In fact, an English-French partnership built a European SST, called the Concorde, which eventually proved to be a commercial failure.  

But I saw nothing wrong with the construction of two US prototypes, as a test of the concept.  However, UCS and others strongly opposed even the prototypes, fearing they would open a path to a commercial fleet.  They therefore raised many other objections, like airport noise and sonic boom.  Eventually, the FAA dropped the program, after a lot of money had been invested in the partial construction of the prototypes.  But the issue of environmental impacts on stratospheric ozone opened up a large amount of federal funding for basic research that eventually led to the finding that manmade chlorofluorocarbons (CFCs, commercially named “Freons”) would deplete the ozone layer.

Estimates of ozone depletion from SSTs varied widely, from a few percent up to 75%.  The National Research Council of the National Academy of Sciences (NRC-NAS) published many reports that documented these different estimates.  [I remember giving testimony to Congress, which critiqued some of the NRC reports that tried to relate ozone depletion and skin cancer rate; they had ignored important statistical correlation effects.]

[To step back, the rate of both basal-cell and squamous-cell skin-cancers (but not that of malignant Melanoma) varies strongly with latitude.  But it is not the variation of ozone content with latitude that matters (as McDonald had proposed), but the angle of the Sun, which of course steepens when one approaches the equator -- thereby traversing less UV-absorbing ozone.  In fact, the calculated depletion of ozone by a fleet of 500 SSTs would correspond in an increase in ultraviolet radiation equivalent to moving from Washington to Richmond, VA, about 100 km to the south.]

In the meantime, our FAA panel continued its deliberations of the environmental impact of SSTs on the ozone layer and of other environmental impacts.

Then it hit me:  I remembered the so-called “Urey-trap.”  Water vapor (WV) would freeze out in the cold upper troposphere and be unable to reach the stratosphere; but methane does not have this problem.  A quick check of available data from balloons confirmed my guess.  Other data confirmed that about half of atmospheric methane was of human-related origin (mainly rice paddies and cattle raising); I figured that it should increase at the rate of population growth and estimated that atmospheric methane levels should rise roughly 1% annually -- the first such prediction.

What’s more:  I could also calculate the rate of increase in stratospheric WV from anthropogenic methane; by chance it turned out to be about what would be injected by a hypothetical fleet of 500 SSTs.  I concluded therefore that innocuous human activities producing methane at the Earth’s surface might affect the ozone layer in the stratosphere; I did not think about investigating CFCs.   Who knows?  I might have shared in a Nobel Prize.

This was probably the first paper that indicated a human influence on stratospheric ozone.  It may have also influenced the work of Rowland and Molina, who published on the effect of CFCs on ozone in 1974.  Like methane, CFCs are quite stable in the troposphere but are photolytically decomposed when they enter the stratosphere, releasing chlorine atoms that can deplete ozone.

The Aftermath

I quickly wrote up my calculations and submitted my manuscript to Science magazine; it was rejected, based on unfavorable comments from reviewers.  I suppose I was being politically “incorrect” in showing that flatulence from friendly cows might cause the same environmental damage as a fleet of the hated SSTs. 

[One of the anonymous referees turned out to be Jules London, a good friend of mine.  He wrote me that he turned down my paper because he “didn’t want me to make a serious error.”  I wrote back and said, I was a big boy now and could take care of myself -- thank you very much.]   

But Nature published my paper in 1971.  There has been no evidence that methane affected the ozone layer and no data series showing any increase in solar UV at the earth’s surface.  But stratospheric WV has finally been detected.

By 1974, it had been recognized by two NASA scientists, Cicerone and Stolarski, that chlorine atoms were effective destroyers of ozone -- through catalytic action.  There followed an intensive propaganda campaign to phase out chlorofluorocarbons (CFCs), which turned out to be a source of stratospheric chlorine, adding to any existing natural (volcanic and oceanic) sources.

The rest is history.   The Antarctic ozone hole (AOH) was discovered by chance in 1985 – with a satellite instrument that I had developed in 1956(!).  The AOH had not been predicted by the Rowland-Molina paper, but it did lead to the 1987 Montreal Protocol to phase out industrial production of CFCs globally -- a blueprint for the 1997 Kyoto Protocol to reduce emissions of greenhouse gasses. 

It will soon be 30 years since the Protocol was adopted by all nations.  The hype that led to it was tremendous; the accomplishments have been few. 


“My Adventures in the Ozone Layer”  National Review  June 1989

“Stratospheric Water Vapour Increase due to Human Activities”  Nature 233, pp. 543-545, Oct 22, 1971

S. Fred Singer is professor emeritus at the University of Virginia and a founding director of the Science & Environmental Policy Project; in 2014, after 25 years, he stepped down as president of SEPP.  His specialty is atmospheric and space physics.  An expert in remote sensing and satellites, he served as the founding director of the US Weather Satellite Service and, more recently, as vice chair of the US National Advisory Committee on Oceans & Atmosphere.  He is an elected Fellow of several scientific societies and a Senior Fellow of the Heartland Institute and the Independent Institute.  He co-authored the NY Times best-seller Unstoppable Global Warming: Every 1500 years.  In 2007, he founded and has chaired the NIPCC (Nongovernmental International Panel on Climate Change), which has released several scientific reports [See].  For recent writings see and also Google Scholar.