The History of Global Climate Change, part 1

While we used many sources for this page, the most important was “The Discovery of Global Warming” at the site of the American Institute of Physics. It is detailed, objective, and well written, and we strongly encourage people to go to the site and read all of it.

Before we begin, let’s clear up a question that confuses a lot of people. Is it global warming or global climate change? Actually, the two terms refer to different things. And both are involved in the current debate over greenhouse gases.

Global warming refers to a change in overall atmospheric temperature brought about by changes in concentration of the so-called “greenhouse gases.” You can learn more about them in the previous section. The theory of global warming has a long history, as we will see. We’ll leave it up to you to decide, by the end of this story, whether or not you believe it has been proven.

Global climate change is anything that causes extreme changes to weather patterns across the entire world, and in particular changes that might be so severe as to change human society. The fear right now is that global warming will lead to global climate change. This would not be the first time global climate change had happened. We know, for instance, that millions of years ago most of the earth was much hotter than it is today. More recently, much of the earth was covered with ice. We know that strong volcanic eruptions have thrown enough dust and debris into the atmosphere to change weather patterns across the planet, and we suspect that collisions with large objects from space lead to sudden, dramatic global climate change. During the Cold War, the fear was that nuclear war would result in a form of global climate change known as nuclear winter. The connection between global warming and global climate change is strongly suspected, but the details, while frightening, are still highly speculative.

Let’s see how we got to where we are today.

Greenhouse gases and global climate change have faded in and out of the public consiciousness of the American people for the past twenty years, and have only recently come to the fore. Scientists around the world have been studying them, with growing concern, for centuries.

The idea that certain gases in the atmosphere could capture heat radiating from the earth was first proposed by French scientist Joseph Fourier in 1824. He called this the “greenhouse effect.” In 1859, The English scientist John Tyndall, working to explain how the Ice Age could have occurred, confirmed that water vapor, carbon dioxide and methane could absorb and reflect heat from infrared radiation. He also speculated that even small changes in atmospheric concentration could have a profound effect on the atmospheric temperature.

The first person to connect climate change and man’s use of fossil fuels was Swedish scientist Svante Arrhenius, in 1896. However, Arrhenius thought that global warming brought about by high greenhouse gas levels was a good thing, because it would help prevent another ice age! Times, and fears, change.

While most scientists accepted Arrhenius’ models, few believed that human industry could possibly produce enough emissions to have a significant impact on something as vast as the earth’s weather.

Nonetheless, it should be noted that agreement among climate scientists on the role greenhouse gases play in global warming dates back more than one hundred years. The questions were: how important was man’s role, and what changes to the earth’s weather would result from an increase in global warming?

For much of the next fifty years, scientists studying global climate change were primarily concerned with the possibility of another ice age. This scared them as much as global warming scares scientists today. Which is why a theory published by Maurice Ewing and William Donn in 1956, which speculated that earlier ice ages had been caused by migration of the poles, and that another ice age might be imminent, caught the public’s attention. Spurred by the public’s reaction, governments directed more money into climate science, and scientists made a new effort to create better models of how weather works.

As models, measurements and processes improved, including the first computers, and as new and better data became available, attitudes began to change about the significance of mankind’s effect on atmospheric greenhouse gas. Many point to a paper published by Roger Revelle and Hans Suess in 1957 as a turning point. Up until then, most scientists had assumed that excess CO2 simply dissolved into the oceans, negating the impact of industrial emissions. Revelle and Suess proved that this didn’t happen, and that the CO2 released into the atmosphere stayed there. The term “global warming” was used for the first time in articles about their research.

At the same time, people were starting to think in new ways about how mankind’s actions could affect the earth. The atomic bomb, and later the hydrogen bomb, had shown just how powerful human technology could be. Books, in particular Rachel Carson’s Silent Spring, published in 1962, made millions aware of the far-reaching effects of industrial and agricultural pollution, and gave rise to the environmental movement in the late 1960s.

Within the community of scientists who studied the weather, consensus was already building, as more and more evidence pointed to the profound and lasting effect of even small changes in greenhouse gas concentration in the atmosphere. With industrialization growing worldwide, and greenhouse gas emissions increasing exponentially, fear of a new ice age gave way to a new, and wholly opposite, fear for the future. In 1965, in the report by the President’s Science Advisory Committee, they presented their concerns about the possible consequences of global climate change brought about by global warming. In 1970, Carroll Wilson, a leading scientist and activist of his time, brought 40 scientists together for the first time to study, discuss and promote their concerns about threats to the environment, including global warming.

Concern within the scientific community was growing. Was it possible the world was already well on the way down a path which ended at a truly frightening place?

Unfortunately, the science of weather is bafflingly complex…ask any weatherman…and we are only today beginning to develop the tools and the mathematical models needed to study and predict it accurately. A whole new field of mathematics has been developed, largely through the study of weather patterns: it’s called chaos theory. So it is little surprise that the scientific community had a difficult time communicating their fears to the public. They had some solid data, but also much speculation and many competing theories. Much of the data was in the form of mathematic calculations and crude computer models.

The media, as it often will, seized on the most extreme speculations and highlighted the disagreements. The public found the speculations unrealistic and the science confusing. This marked the point where public perception of global climate change, and the perception of the scientists who study it, diverged. This split remains to this day. The public is skeptical and divided; the scientific community, despite what many still believe, is not.

A class of greenhouse gases brought atmospheric science front and center in the public’s attention in the 1970s, but global warming had nothing to do with it. Chlorofluorocarbons (CFCs) absorb infrared radiation; they also destroy ozone, and this became a very serious concern. CFCs were commonly used in aerosol spray cans and refrigerators, and it was discovered that years of constant emissions had damaged the ozone layer that protects earth from the harmful ultraviolet rays of the sun. Government action was demanded and taken, and CFCs were partially banned in America and a few other countries, despite a publicity campaign by the chemical industry to undermine the science and sway public opinion. The partial ban wasn’t enough, however; in 1983 the “ozone hole” over Antarctica was discovered, and America’s ban would eventually grow to a global one.

CFCs forced people to recognize that the actions of one individual, multiplied by the millions of people on earth, could have a global impact. If something as trivial as spritzing your hair could damage the ozone in the stratosphere, what other common activities might be doing damage? And if it was possible to undo the damage just by giving up spray cans, what else might we have to give up in the future to protect the earth?

Another event of the early 1970s, the OPEC oil embargo, gave Americans a stark reminder of how much they depended on fossil fuels, and how deeply engrained fossil fuels were in the development of American society. For the first time, people began to consider the benefits of the emerging “green” technologies of solar and wind power.

The 1980s was a period of political conservatism in the United States. Global warming was out of public discussion. Yet environmental issues continued to make the news, and most of the stories were not good. Acid rain, toxic waste and species extinction were stark reminders of how much damage human technology could do, and that environmental problems didn’t go away just because they were out of the public eye.

Within the community of weather scientists, concern was growing that global warming was no longer a possibility, but instead was already happening; 1980, 1981 and 1983 were each record years for global temperature.

Global warming returned to the public’s attention with a bang in 1988, when Jim Hansen, a climate scientist who had done some of the most advanced computer modeling, told a congressional committee that global warming was “a certainty” and could happen within a decade. The fact that he made this prediction during the long, hot summer of the hottest year in recorded history made the media take notice.

And thus, the global climate change debate began in earnest. Things were about to get very interesting. Read part 2 to find out what happened next.

By the way, if you follow up this story by doing some research on greenhouses, you will discover that Fourier wasn’t correct when he coined the term “greenhouse effect.” Greenhouse gases do trap the sun’s heat; so do the glass buildings we use to grow flowers through the winter. But while the result is similar, the process by which it happens is completely different. Fourier thought the atmosphere was a thin sheet, like a pane of glass. We know today that it is miles high, with many layers. Science often works like this; we discover the results first, then gradually uncover the processes behind them.

The term “greenhouse gas” didn’t come into wide use until the 1960s. It works well enough to help people understand what’s going on, so it looks like it’s here to stay.