Fixing the Sky

by James Rodger Fleming

  a. increase global temperature by 1.7°C [3°F] by injecting a cloud of ice crystals into the polar atmosphere by detonating 10 H-bombs on the Arctic sea ice;

  b. lower global temperature by 1.2°C [2.2°F] by launching a ring of dust particles into equatorial orbit to shade the Earth;

  c. warm the lower atmosphere and cool the stratosphere by injecting ice, water, or other substances into space; and

  d. destroy all stratospheric ozone, raise the tropopause, and cool the stratosphere by up to 80°C [144°F] by an injection of a catalytic de-ozonizer such as chlorine or bromine.73

  Cutting a Hole in the Ozone Layer

  One of the most stunning aspects of Wexler’s lectures was his awareness that catalytic reactions of chlorine and bromine could severely damage the ozone layer. Wexler was concerned that inadvertent damage to ozone might occur if increased rocket exhaust polluted the stratosphere or if near-space “seeding” experiments went awry: “The exhausts from increasingly powerful and numerous space rockets will soon be systematically seeding the thin upper atmosphere with large quantities of chemicals it has never possessed before or only in small quantities.”74 He was also concerned that the cold war and the space age might provide rival militaries with both the motivation and the wherewithal to damage the ozone layer. He cited a 1961 study by the Geophysics Corporation of America on possible harm to the Earth’s upper atmosphere caused by the oxidizers in rocket fuel. He was also aware that Operations Argus and Starfish, Project West Ford, and Project High Water constituted recent significant interventions in the near-space environment that were accompanied by unknown and unquantified risks.

  On the topic of purposeful damage, Wexler turned to the 1934 presidential address to the Royal Meteorological Society, in which the noted geoscientist Sydney Chapman had asked, “Can a hole be made in the ozone layer?”75 That is, can all or most of the ozone be removed from the column of air above some chosen area? Chapman was thinking of an event that would provide a window for astronomers to extend their observations some hundreds of angstroms farther into the ultraviolet without the interference of atmospheric ozone. Possible health effects of human exposure to shortwave radiation did not appear to Chapman to be an important issue, since the hole he was contemplating would be localized, probably in a remote area (he suggested Chile), and would be short-lived, somewhere between a day and an hour, timed for the benefit of astronomers only. Cutting such a hole, Chapman continued, would require “the discharge of a deozonizing agent” perhaps by airplanes, balloons, or rockets. Chapman proposed two possibilities: a large amount of a one-to-one destructive agent such as hydrogen that would reduce O3 molecules to O2 or “some catalyst which, without itself undergoing permanent change, could promote the reduction of large numbers of ozone molecules in succession” (134). Although the choice of the agent would have to be left to the chemists, Chapman concluded that “the project of making a [temporary] hole in the ozone layer [a 90 percent reduction for the benefit of astronomers] does not seem quite impossible of achievement” (135).

  In November 1961, Wexler gathered weather bureau staff for a briefing on ozone depletion and circulated this memo, titled “Deozonizer”:

  Sydney Chapman proposed making a temporary “hole” in the ozone layer by inserting a substance which could be oxidized by the ozone. He suggested that hydrogen might be dispersed but wondered if there might be a catalyst gas or fine powder which might perhaps be dispersed in smaller quantities than the 1 to 1 ratio hydrogen would require. Could you or your colleagues suggest suitable agents that might do the job with maximum efficiency consistent with the least weight?76

  Bill Malkin suggested that Wexler might wish to raise the possibility with the country’s national defense research arm, “that serious consideration be given to the possibility of artificially and temporarily altering (up or down) the ozone concentration over an area, as a most effective weapon.”77 Using the radiation model of Syukuro Manabe and F. Möller, Wexler was able to calculate a catastrophic 80°C (144°F) stratospheric cooling that would occur with no ozone layer.78

  Seeking further advice on how to cut a “hole” in the ozone layer, Wexler turned to chemist Oliver Wulf at Caltech, who suggested that “from a purely chemical viewpoint, chlorine or bromine might be a ‘deozonizer.’”79 Wulf and Wexler exchanged numerous letters between December 1961 and April 1962 and met face-to-face in March, and Wulf met with Chapman in April. All these exchanges point to the conclusion (a stunning one, given the received history of ozone depletion) that chlorine or bromine atoms might act in a catalytic cycle with atomic oxygen to destroy thousands of ozone molecules. For example, Wulf wrote in early January 1962, “chlorine or bromine photosensitized decomposition [of ozone] might come closest to a reaction in which a small amount of added material would cause a relatively large amount of decomposition.” 80 Wexler replied immediately, adding that he even had a delivery system in mind “à la West Ford dipoles” but had “no intention of suggesting or backing any such proposal.”81

  Wexler estimated that a 100-kiloton bromine “bomb” would destroy all ozone in the polar regions, and four times that amount would be needed near the equator. In a handwritten note composed in January 1962 he scrawled the following (figure 7.6):

  UV decomposes O3 → O in presence of a halogen like Br, Cl.

  O → O2 and so prevents O3 from forming.

  100,000 tons Br. could theoret[ically] prevent all O3 north of 65°N from forming.

  And in another note (figure 7.7):

  Br2 → 2 Br in sunlight destroys O3 → O2 + BrO

  These are essentially the basis of the modern ozone-depleting chemical reactions.

  7.6 (top) Harry Wexler’s handwritten note on ozone depletion, January 1962. (WEXLER PAPERS)

  7.7 (bottom) Harry Wexler’s handwritten note on bromine reactions, January 1962. (WEXLER PAPERS)

  Wexler’s rough note of December 20, 1961, jotted down during a telephone conversation with Wulf, constitutes an ozone-depletion Rosetta Stone.82 It links Chapman’s 1934 speech, Wulf, rocket fuel emissions, ozone-destroying reactions triggered by chlorine and bromine as catalysts, particulates, methane destruction, and an estimate that a minuscule amount of atomic bromine could cause immense harm (figure 7.8).

  In the summer of 1962, Wexler accepted an invitation from the University of Maryland Space Research and Technology Institute to present a lecture titled “The Climate of Earth and Its Modifications” and might, under normal circumstances, have prepared his ideas on geoengineering and ozone destruction for publication. However, he was cut down in his prime by a sudden heart attack on August 11, 1962, during a working vacation at Woods Hole. The documents relating to his career—from his early work at MIT, his work as liaison to the IAS meteorology project, his research into all sorts of new technologies, to his final speeches on ozone depletion and climate control—headed into the archives, probably not to be seen and certainly not to be reevaluated until today.

  7.8 Harry Wexler’s “Rosetta Stone” note, linking Sydney Chapman, Oliver Wulf, rocket fuel, and catalytic ozone-destroying reactions triggered by chlorine and bromine. (WEXLER PAPERS)

  The well-known and well-documented supersonic transport (SST) and stratospheric-ozone-depletion issues date only to the 1970s and do not include Wexler’s role. The idea that bromine and other halogens could destroy stratospheric ozone was published in 1974, while chlorofluorocarbon production expanded rapidly and dramatically after 1962.83 Had Wexler lived to publish his ideas, they would certainly have been noticed and could have led to a different outcome and perhaps an earlier coordinated response to the issue of stratospheric ozone depletion. Recently, I have been in correspondence with three notable ozone scientists about Wexler’s early work: Nobel laureates Sherwood Rowland and Paul Crutzen and current National Academy of Sciences president Ralph Cicerone. They are uniformly interested and quite amazed by Wexler’s insights and accomplishments.

  Remarkable, too, is the fact that with all his
sophistication and the leading roles he played in the development of computer modeling, satellite monitoring, and many, many other technical fields, Wexler still opened his 1962 lectures by quoting extensively from Zworykin’s “Outline of Weather Proposal” (1945) and von Neumann’s response to it. A colleague who heard Wexler’s lecture in Boston wrote that climate engineering constituted “a delightful area of mental gymnastics. Let’s hope the entire world is satisfied to play the game on this plane until the state of meteorological knowledge is truly adequate for big league experimentation.” 84 Wexler replied, “I hope that before we get into large experimentation that not only will the state of meteorological knowledge be much more advanced than it is now, but also the state of our socio-political affairs as well.”85 Remember, it was not Paul Crutzen in 2006 but Harry Wexler about fifty years before who first claimed that climate control was now “respectable to talk about,” even if he considered it quite dangerous and undesirable.

  The possibility of manipulating global climate through planetary-scale engineering is currently being actively debated, although its feasibility and desirability are highly questionable, if not contentious. Most of the debate centers on back-of-the -envelope calculations (which are not good enough) or basic climate models (which are also not good enough). Still, the current crop of geoengineers has yet to acknowledge the checkered history of the subject.

  Accounts of the early history of computers in meteorology follow a wellrehearsed script, identifying Vilhelm Bjerknes and Louis Fry Richardson as early pioneers and emphasizing progress after 1946 through the work of a familiar cast of characters and technical breakthroughs. Through the career of Harry Wexler, we can now see that the two histories, the familiar and the (until now) unwritten, are closely interrelated and that climate control is not so much a newcomer in the age of global warming as something that has been up in the air for quite a long time.

  The recent history of climate fears, fantasies, and possibilities is positioned firmly between the work of two colleagues, John von Neumann and Harry Wexler. An examination of general climate fears and specific climate fantasies reveals that some were no more than hand-waving proposals, while some were actual field projects. Anchoring this in time were the high hopes that futurists had for new emerging technologies such as digital computers, to provide stunning precision and predictability; nuclear energy, to power continental-scale transformations or violently alter the geophysical status quo; and satellites, to monitor the Earth continuously with eagle eyes and to serve as platforms for active interventions.

  Wexler’s work on geoengineering in the period 1958 to 1962 applied the results of new computer climate experiments, nuclear tests in near space, and newly available satellite heat budget measurements. His work on ozone destruction, in particular, is notable since it predated the Nobel Prize–winning work of Paul Crutzen, Sherwood Rowland, and Mario Molina by about a decade, although Wexler died before he could publish the results. It is clear that Wexler was well qualified to speak authoritatively about the otherwise “nebulous” subjects of climate, climate change, and climate control. He served on numerous scientific panels and governmental advisory boards, had access to and helped collect global climate data, understood the theoretical issues and their complexity, and promoted and advanced the latest technologies. He warned then, and we might wisely conclude today, that

  [climate control] can best be classified as “interesting hypothetical exercises” until the consequences of tampering with large scale atmospheric events can be assessed in advance. Most such schemes that have been advanced would require colossal engineering feats and contain the inherent risk of irremediable harm to our planet or side effects counterbalancing the possible short-term benefits.86

  Based on the visionary foundation provided by Vladimir Zworykin and John von Neumann, and the much more speculative megaprojects being proposed at the time, Wexler’s prescient work “On the Possibilities of Climate Control” clearly reminds us that we are not the first generation to be involved with or concerned about geoengineering and places the current debate in the context of at least half a century of continuous and usable history.

  8

  THE CLIMATE ENGINEERS

  How can you engineer a system whose behavior you don’t understand?

  —RON PRINN, QUOTED IN MORTON, “CLIMATE CHANGE”

  DURING the unusually hot summerof 1988, with a major heat wave in in the American Midwest, Yellowstone National Park in flames, and issues such as ozone depletion in the headlines, climate modeler James Hansen of NASA announced to the world that “global warming has begun.”1 Hansen reported that he was “99 percent certain that the warming trend was not a natural variation but was caused by a buildup of carbon dioxide and other artificial gases in the atmosphere” and that anthropogenic greenhouse warming “is already happening now.” He predicted more-frequent episodes of very high temperatures and drought in the next decade and beyond. Hansen later revised his remarks, but his statement remains the starting point for recent widespread concern about global warming. The question was no longer whether human agency had contributed to global change. That question was answered in the affirmative long ago. The more significant questions involved the magnitude and consequences of the global changes being caused by a combination of natural forces and increasing anthropogenic stresses and what was to be done about it.

  That summer, the government of Canada, in collaboration with the United Nations Environment Program (UNEP) and the World Meteorological Organization (WMO), convened a major conference on the topic “The Changing Atmosphere: Implications for Global Security.” The conference statement captured the tone and urgency first expressed in the 1950s by Roger Revelle and John von Neumann: “Humanity is conducting an unintended, uncontrolled, globally pervasive experiment, whose ultimate consequences could be second only to a global nuclear war.”2 The conference recommended reductions of carbon dioxide emissions to 20 percent below 1988 levels, to be achieved by 2005. Needless to say, we did not reach this goal, but a process had been put into motion to set new goals and deadlines.

  Also in 1988, the WMO and UNEP established the Intergovernmental Panel on Climate Change (IPCC), whose purpose is to provide periodic assessments of “the scientific, technical and socioeconomic information relevant for the understanding of the risk of human-induced climate change.”3 From modest beginnings, the IPCC has emerged as a representative parliamentary body that has gradually acquired status and authority. It has prepared four major assessments to date, the first in 1990 in preparation for the 1992 Earth Summit in Rio de Janeiro. Here the UN Framework Convention on Climate Change (UNFCCC) set an ultimate objective of stabilizing atmospheric concentrations of greenhouse gases at levels that would prevent “dangerous” human interference with the climate system.4

  Each of the subsequent IPCC reports (1995, 2001, 2007) has expressed a sense of greater urgency about the climate change problem. The IPCC consensus involves six key points:

  1. Anthropogenic emissions are changing the composition of the atmosphere, especially by increasing its radiatively active trace gases.

  2. This will enhance the greenhouse effect and will result in long-term global warming.

  3. Observed changes in climate on decades-to-centuries time scales are consistent with human influence.

  4. Models indicate that future warming is likely to be substantial.

  5. Both environment and society will be adversely impacted.

  6. Avoiding dangerous human influence in the climate system will require substantial early actions, but may not provide direct benefits for several generations.5

  It is still not clear what “dangerous human influence” in the climate system actually is or how to avoid it, but mitigation, adaptation, and intervention through climate engineering are now on the table. Deindustrialization will also reduce greenhouse gas emissions, as demonstrated by the political and economic collapse of the Soviet Union.

  Ratcheting up the sense of urgency, in
2005 Hansen warned that the Earth’s climate is nearing an unprecedented “tipping point”—a point of no return that can be avoided only if the “growth of greenhouse gas emissions is slowed” in the next two decades:

  The Earth’s climate is nearing, but has not passed, a tipping point beyond which it will be impossible to avoid climate change with far-ranging undesirable consequences. These include not only the loss of the Arctic as we know it, with all that implies for wildlife and indigenous peoples, but losses on a much vaster scale due to rising seas.... This grim scenario can be halted if the growth of greenhouse gas emissions is slowed in the first quarter of this century.6

  According to Hansen, tipping points occur because of amplifying feedbacks, including loss of sea ice, melting glaciers, release of methane in warming permafrost, and growth of vegetation on previously frozen land. These surface and atmospheric changes increase the amount of sunlight absorbed by the Earth and amplify the warming effect of carbon dioxide produced by burning fossil fuels. Hansen’s brief statement, widely distributed by the press, clearly struck a cultural nerve. It acknowledged undesirable and inadvertent human influence on the climate system and pointed to a possible remedy. In the interest of impact, however, Hansen avoided complexities. For example, it is highly unlikely that merely slowing the growth of emissions would be a very effective policy. Hansen may be right: we may be approaching the physical tipping point of climate, or, as James Lovelock argued in his book The Revenge of Gaia, we may already have passed it, with catastrophic consequences for humanity.7 More likely, Hansen, Lovelock, and many others are trying to add the weight of their opinions to a second kind of “tipping point,” a behavioral change in which humanity decides to live with only clean energy and takes concerted action against harming the climate system. There is also a third “tipping point”—one that has been reached by a handful of geoengineers who are so concerned about climate change that they are proposing purposeful, even reckless, intervention.