THE COLD WAR ROOTS OF GLOBAL WARMING
IN THE ARCHIVES OF THE SCRIPPS INSTITUTION OF OCEANOGRAPHY IS
a photograph of a young Roger Revelle—age twenty-seven or so—sorting specimens on the deck of the collecting vessel E. W. Scripps.
The year is circa 1936, and Revelle's setup looks decidedly ad hoc. He sits on what look to be the wooden slats of the aft deck, right leg bent beneath him and left leg splayed out, amid an assortment of mason jars, collecting rags, and a bucket. In a black wool sailor's jacket, with one sleeve rolled up and cuffed white trousers stained at the knees, he is hardly the picture of a careful, plodding scientist. He looks a little bit like I imagine James Dean might have, had he played an oceanographer: intensely focused and unflappably cool, taking care of the business of collecting specimens while enjoying the ocean breeze on a boat named for a member of the family into which he had married—the namesake also of the Scripps Institution of Oceanography, from which he would earn a Ph.D. and which he would eventually direct. More than anything, as Revelle looms over the little mason jars, his hand enveloping whatever tiny specimen he is picking up at the moment, the man in the photograph—the self-appointed “‘granddaddy’ of the theory of global warming”—looks altogether too big for whatever specific form of science he is conducting.1
Roger Revelle was a good oceanographer. He was an excellent science administrator, and he was an even better science advocate. He was also
interested in CO2
, and perhaps no individual in the 1950s and 1960s did more than Revelle to put atmospheric CO2
and climate change on the Cold War research agenda.2
In 1958, when Charles David Keeling began permanent operations at Mauna Loa and atmospheric CO2
measured about 315 ppm, Revelle was Keeling's boss.
The introduction of CO2 into the Cold War research system marks the beginning of the political history of global warming. Between 1955 and 1963, Revelle and a handful of creative and influential scientists capitalized on existing government research to gain funding and support for specific projects that involved measuring and monitoring atmospheric constituents like CO2. They tapped into a pervasive interest in geophysical research that might have a bearing on weather modification, nuclear test detection, fallout, or other defense-related subjects in order to solicit funding and material support for atmospheric science. Soon, leaders in atmospheric science realized that in order to more fully study the processes of the atmosphere, they needed to secure funding for scientific institutions that could support long-term projects. Again, they capitalized on the potential security implications of geophysical research, and again they incorporated CO2 into the heart of atmospheric science.
Tying the study of CO2 to Cold War research enabled scientists to revisit CO2 with new eyes, but there were two sides to the Cold War research coin. On one side, funding, new technologies, and institutional support gave scientists access to better data that confirmed that CO2 had, in fact, begun to rise, and that its increase could have geophysical consequences. Revelle in particular framed CO2 rise as a form of natural experiment, one that the new tools and technologies of Cold War science could help to monitor. On the other side of the coin, however, scientists harbored anxieties born of the Cold War, and these anxieties influenced how they structured their institutions, employed their new Cold War resources, and interpreted study results. As a result, in the 1950s and 1960s, research on atmospheric CO2—and atmospheric science more broadly—reflected both the greatest hopes and the deepest fears of the Cold War milieu from which it sprang.
THE GRAND EXPERIMENT
Revelle's contributions to climate change history were both administrative and scientific. His most important scientific contribution involved a
reevaluation of the role of the oceans in the global carbon cycle, a study supported by funds from the Office of Naval Research (ONR) and the Atomic Energy Commission (AEC).3
In the early 1950s, nuclear weapons tests dumped large, known amounts of radiation into the atmosphere at specified times and places, and both the ONR and AEC had a keen interest in where that radiation went. One way to trace it was by following radioactive carbon through the atmosphere. In fact, alongside naturally occurring cosmic radiation, nuclear tests created a nearly ideal experiment for tracing the circulation of carbon through both the atmosphere and the oceans.4
Amid nascent concerns about nuclear fallout from bomb tests at Bikini Atoll (where then-navy commander Revelle had headed a team studying a coral lagoon in 1946) and elsewhere, the government began to ask oceanographers like Revelle just how fast the oceans could swallow up the carbon that the U.S. military was irradiating in the atmosphere.5
In 1955, Revelle began working on the problem with Hans Suess, an Austrian-born physical chemist, nuclear physicist, and radiocarbon dating expert whom Revelle had hired at Scripps with ONR/AEC funding. While at the U.S. Geological Survey's laboratory in Washington, D.C., Suess had described a characteristic of the carbon cycle that would help Revelle in his attempts to use measurements of radiocarbon in air and seawater to investigate the rate of CO2 exchange between the oceans and the atmosphere.
As plants grow, they “fix” the carbon from atmospheric CO2
in their leaves, trunks, stems, and shoots, including a naturally occurring radioisotope of carbon called carbon 14 (C14
In 1949, Willard Libby of the University of Chicago devised a method for measuring the rate at which C14
decays, giving archeologists and paleontologists a new way of dating very old relics and the dirt they came from—a method called radiocarbon dating. Suess, interested in geochemical cycles, applied Libby's idea a little differently. Not all carbon is C14
; most, in fact, is “normal” carbon, or C12
. Using Libby's rate of decay, Suess calculated what the overall ratio of C14
in the atmosphere should
be, given approximate time scales for major influences on CO2
such as weathering and ocean mixing. The ratio came out low—that is, there was less C14
in the atmosphere relative to C12
than Suess's calculations predicted. He concluded that the whole mix must have been diluted, most likely by carbon from some ancient source in which most or all C14
isotopes would have decayed. Fossil fuels, which
are stored in the earth's crust for millions of years and thus have little if any C14
, presented just such a source. The dilution of atmospheric carbon with fossil fuel carbon is known as the Suess effect. It provided a radiochemical confirmation of a contention made in 1938, by an obscure British steam engineer named Guy Stewart Callendar, that fossil fuel use contributed CO2
to the atmosphere.7
At first, Revelle and Suess both assumed—like many other scientists—that the oceans would absorb this excess CO2
, and the two men hoped to study and trace radioactive CO2
as it circulated through the atmosphere and found its way into the seas. Shortly before they sent their paper on the subject to the journal Tellus
in 1957, however, it occurred to Revelle that they had failed to account for the tendency of seawater—a complex and often poorly stirred chemical mélange—to retain a generally constant acidity through a self-regulating “buffering” mechanism involving CO2
that most scientists assumed would be absorbed might just as easily be re-released while still at the ocean surface, resulting in the overall increase in atmospheric CO2
that Callendar, for different reasons, had predicted. That increase could in turn have interesting and far-reaching geophysical significance.
“Human beings,” Revelle famously wrote, “are now carrying out a large scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future. Within centuries we are returning to the atmosphere and oceans the concentrated organic carbon stored in sedimentary rocks over hundreds of millions of years. This experiment, if adequately documented, may yield far-reaching insight into the processes determining weather and climate.”9
In retrospect, Revelle's “grand experiment” statement has been framed as an early warning on global warming, but at the time Revelle and Suess were more curious and excited than anxious. As a colleague later remembered, “Roger wasn't alarmed at all…he liked great geophysical experiments.”10
Indeed, Revelle's realization about buffering was a late addition to the Revelle-Suess paper, which on the whole actually challenged the extent of the so-called Callendar Effect. Nevertheless, the paper's conclusion—and, more importantly, its authors—made an impact on the way scientists and their government sponsors interpreted atmospheric CO2
for the next half century. That impact began with the advent of the Keeling Curve.
For Revelle, the immediate danger in the grand experiment was that
it might not be adequately monitored and documented.11
Master of the science-funding alphabet, he took steps to ensure that it was. Taking advantage of resources available to him as the president of the Scientific Committee on Ocean Research (SCOR), a committee of the International Council of Scientific Unions (ICSU), Revelle designed an atmospheric-monitoring program for the 1957–58 International Geophysical Year (IGY).12
In July of 1956, the Scripps Institution of Oceanography had hired Keeling as a junior scientist, and he brought his pathological obsession with measuring atmospheric CO2
with him to La Jolla. In 1957, Revelle set Keeling up with IGY funds (and about $10,000 of dubiously allocated AEC money) and put him in charge of the new IGY atmospheric-monitoring program.13
Keeling constructed CO2
-monitoring stations at the Mauna Loa Observatory in Hawai'i and at a research post in Antarctica in order to establish a baseline of atmospheric CO2
that could be used to measure future changes.14
In March of 1958, the amount of CO2
in the atmosphere stood at about 315 ppm.15
CO2 AND THE INTERNATIONAL GEOPHYSICAL YEAR
The Keeling Curve would eventually become an icon of global warming, but in the spring of 1958 the curve was still only a few data points on a plotter, and Keeling was little more than “a peculiar guy” living on a volcano and trying to figure out the best way to measure CO2
Technically, Keeling's Mauna Loa Observatory put CO2
research on the government payroll, but it was Revelle's involvement in planning the International Geophysical Year that really landed CO2
on the public research agenda.
Lasting from July 1, 1957, to December 31, 1958, the IGY was the largest cooperative international scientific research effort the world had ever seen. The idea arose from a 1950 gathering of physicists interested in the ionosphere; in less than a decade it blossomed into a project involving more than sixty thousand scientists and technicians from sixty-six nations.17
The initial group met at the home of James Van Allen, a rocket scientist concerned primarily with cosmic rays. Also present were Lloyd Berkner, a physicist who would become both president of the ICSU and a member of Eisenhower's Science Advisory Committee; Sidney Chapman, a man that New York Times
science writer Walter Sullivan dubbed the world's “greatest living geophysicist”; and three other physicists, J. Wallace Joyce,
S. Fred Singer, and Ernest H. Vestine.18
Envisioned as an updated version of the International Polar Years of 1882–83 and 1932–33, the IGY had a major polar science component but focused primarily on the physics of the earth's atmosphere. In fact, with projects in meteorology, climatology, ionospheric physics, aurora and airglow, cosmic rays, and solar activity, the IGY agenda defined what would become known more broadly as the field of “atmospheric science.”19
Scientists designed the IGY to tackle a range of large-scale research interests, but from the beginning it was also a deeply political affair. Not surprisingly, in the international arena the politics of the IGY revolved primarily around Cold War U.S.-Soviet relations. These politics played out in the language of institutional acronyms.20
The IGY was administered by the International Council of Scientific Unions (ICSU), with support from the United Nations Educational, Scientific, and Cultural Organization (UNESCO) and the World Meteorological Organization (WMO). Under Stalin, however, the Soviet Union had decided not to adhere to the ICSU, and that decision persisted through the process of “de-Stalinization” in the 1950s (the Soviets did belong to the International Astronomical Union and the WMO, however). The Soviet Union was thus not included in the original list of twenty-six invited nations, and the U.S. National Committee for the IGY had to persuade the ICSU to send the Soviets a special invitation.21
The Soviets took eighteen months to accept, and once they did, their cooperation was limited. Soviet officials resisted proposals to allow scientifically oriented overflights by foreign nationals within Soviet borders, and Soviet scientists refused to discuss their nation's rocketry and artificial satellite programs. The rest of the Soviet IGY program was every bit as extensive as the United States' proposed plan—perhaps more so—but cooperation between the two superpowers took a back seat to what IGY boosters spun as healthy scientific competition between the communist East and the capitalist West.22
The recent detonation of hydrogen bombs by both sides—the Americans' “Ivy Mike” in 1952, the Soviets' “Joe 4” in 1953—lent this competition a certain urgency.23
In the United States, popular concerns about nuclear weapons testing and the perceived gap between the quality of American and Soviet science gave American scientific leaders like Revelle, Berkner, and U.S. Weather Bureau chief Harry Wexler the latitude to push for a comprehensive program of geophysical research for the IGY—including research on CO2
climate. Funding for the American portion of the IGY came from Congress, primarily via the National Science Foundation. In May of 1957, members of the National Committee for the IGY—Wexler, Berkner, and Revelle among them—went before the House Appropriations Committee to ask for $39 million to run their eighteen-month program, including more than $2 million for oceanographic research and almost $3 million for research in meteorology.24
In testimony that covered everything from the aridity of the Martian atmosphere to the depth of the Gulf Stream, Revelle introduced members of Congress to the possible relationship between an increase in CO2
and an increase in global temperature, and he noted the many uncertainties that a program in CO2
monitoring could hope to resolve. Congress approved the program, and ultimately IGY vessels and stations measured CO2
at sixty locations around the world.25
For eighteen months a full half century ago, CO2
stood on the front lines of Cold War science.
FORECASTS AND MODELS
Revelle's growing interest in CO2
paralleled other developments in climate-related atmospheric science that were also entangled in the web of Cold War research. These were developments in atmospheric modeling, in particular the advent of general circulation models.26
Early numerical models of the earth's atmosphere grew out of efforts to use computers to forecast weather accurately during and after the Second World War, and in the ensuing decade scientists began to modify these models to attempt to predict changes in climate. Even more so than CO2
monitoring efforts, models of the atmosphere had obvious applicability to questions about fallout and the potential distribution of radioactivity in the event of a nuclear exchange. In addition, some scientists and politicians linked modeling the weather and climate to controlling these geophysical forces, both for the domestic good via rainmaking and as a powerful Cold War weapon. Ultimately, the combination of the Scripps Instit...