Everyone has a favorite decade, and for Climate deniers, that decade has got to be, the 70s. Yes, the decade of disco, kung fu, and watergate. I shall resign the presidency effective at noon tomorrow… Because in the 70's, deniers will tell you, all climate scientists believed an ice age was coming. Those crazy climate scientists! Why can't they make up their minds? But is that really true? The first calculations relating CO2 emissions to climate change were done by Svante Arrhenius in the early 20th century. [Correction: The year was 1898] His ideas received some attention, but were largely ignored for many decades. With the advent of the cold war, the US military poured money into sophisticated research using new instruments and computers to investigate radiative transfer at high altitudes helping create a new generation of heat seeking missiles. By the early 1950s, the issues were well resolved, and Popular Mechanics noted that the essentials of the CO2 greenhouse warming were now understood. Gilbert Plass, of Johns Hopkins University, was a leader in this effort, having used newly available computers and technology to show that adding more CO2 to the atmosphere did indeed soak up and radiate more heat. In 1957, the international Geophysical year brought modern technology to bear world wide on issues of weather and climate.
By 1958, Americans learned about the greenhouse effect from the all knowing and avuncular character of Dr Frank Baxter, in this Bell Telephone Science hour, directed by Frank Capra. Even now man may be unwittingly changing the world's climate through the waste products of the civilisation. Due to our release through factories and automobiles every year of more than six billion tons of carbon dioxide which helps air absorb heat from the Sun. Our atmosphere seems to be getting warmer. This is bad? Well, it's been calculated that few degrees rise in Earth temperature would melt the polar ice caps. And if this happens an inland sea would fill a good portion of Missisippi walley. Tourists from glass bottom boats would be viewing the drowned towers of Miami through 150 feet of tropical water.
For in weather we're not only dealing with forces of a far greater variety, than even the atomic physicist encounters, but with life itself. By the 1960s, the importance of a presidential scientific advisory panel became clear. President Johnson's Science Advisory Committee in 1965 produced a groundbreaking study on natural beauty and the environment, which contained a clear warning about climate and CO2. “Man is unwittingly conducting a vast geophysical experiment….”, noting that emissions by the year 2000 could be enough to cause “measurable and perhaps marked” climate change. In a special message to congress of February 8, 1965, President Johnson wrote, "…this generation has altered the composition of the atmosphere on a global scale through radioactive materials and a steady increase in carbon dioxide from fossil fuels." But a few scientists were looking at global temperature data, and beginning to worry about another pollution problem. Global Temperatures had been flat or decreasing since the 1940s.
Could man's addition of smoke and particulate matter to the atmosphere be blocking out the sun and leading to a potentially catastrophic global cooling? One of them was climatologist Stephen Schneider, who contributed to a widely quoted paper on the issue. Well nobody likes to be wrong. But remember I never said "I predict that we are going to induce an ice age." What I said was under these assumptions this is what you get. Other scientist say that could trigger an ice age. Even though a discussion was going on between a few scientists, popular media still reflected awareness of impending global warming. When I was a kid, food was food. Before our scientific magicians poisoned the water, polluted the soil. Decimated plant and animal life. Why in my day you could buy meat anywhere.
Eggs they had. Real butter. Fresh lettuce in the stores. I know. Sol. You told me before. How can anything survive in a climate like this. A heat wave all year long. A green house effect. Everything is burning up. Ok wiseguy. News of the scientist's concerns made its way into the popular media, such as this 1975 Newsweek article. The article quoted a number of scientists, and in addition, a National Academy of Science study pointing out that a change in climate would have impacts on global food supply. The Academy was also quoted saying that, in regard to climate change, in many cases we do not yet know enough to pose the key questions. Since the National Academy is a good bellweather of where science was at that moment, I decided to read what the original study actually said.
This particular study is a model of ambiguity. "..we do not have a good quantitative understanding of our climate machine. Without the fundamental understanding, it does not seem possible to predict climate.." The report concludes by saying, "The onset of cooling could be several thousand years in the future, though there is a ﬁnite possibility that a serious worldwide cooling could befall the earth within the next 100 years." And a few paragraphs later, “A leading effect is the enrichment of the atmospheric CO2 and such effects may combine to offset a future natural cooling, or to enhance a natural warming.” It was an uncharacteristically muddled effort by the academy, and its conclusions were somewhat distorted in media accounts. In early 1977, the Global 2000 report to President Jimmy Carter, was clear and explicit about climate. “Rising CO2 concentrations are of concern because of their potential for causing a warming of the earth. Agriculture and other human endeavors would have a great difficulty in adapting to such large, rapid changes in climate.
” In 1979, the Academy took another crack at the issue, surveying the balance of all the scientific literature of the 70s, and reported: "If Carbon dioxide continues to increase, there is no reason to doubt that climate changes will result, and no reason to believe that these changes will be negligible…. Ominously they warned, A “wait and see policy may mean waiting until it is too late..” By the mid seventies, a couple of things had happened to clarify our situation. Number one, global temperatures began a sustained rise that matched the predictions of CO2 effects. Number two, the publication of a seminal study marked the beginning of the contemporary view of climate change, and the cycle of ice age glaciations. The study confirmed a decades old theory, and gave us an understanding as to how the long slow changes in earth's rotation and orbit have been the timing clock of the glaciers. These cycles has been discussed in some other additions of this series. But with this study, the stage was set for our current generation of scientists to gain a whole new understanding of where we are in climatic cycles, and what to expect in the future. But, climate deniers still point to the popular media as evidence of what climate scientists were thinking at the time.
But of course, the gold standard in science is not pop culture, but the peer reviewed study published in a reputable journal. Most climate Deniers, bless their hearts, don't know the difference. But real scientists do. If there was still any question of what the majority of climate scientists thought in the 1970s, in 2008, a study published in the Bulletin of the American Meteorological Society finally put that question to rest. In a survey of 71 peer reviewed studies from 1965 to 1979, 7 predicted cooling, 20 were neutral, and 44 predicted Global Warming. The study concluded that global cooling was never more than a minor aspect of the scientific" literature of the era, let alone a consensus" comparable to the agreement of every established scientific organization on the planet that exists today, that climate change is real, we're doing it, the consequences are dire, and we need to stop. Thanks again for helping make this series a success. I hope you keep coming back for more on climate issues and solutions. Here on Climate Denial Crock of the Week..