Climate change refers to any change in the earth’s climate- natural or human caused. Global warming refers to the trend towards higher mean temperatures seen recently worldwide.
The narrative of global warming evolved from being a subject of interest to a few scientists to becoming a major issue of national and international policy. The Pulitzer Prize winner Daniel Yergin in his book The Quest: Energy, Security, and the Remaking of the Modern World, explains how this all happened. He follows the history of climate change science from its beginnings in the late 18th century through the controversies that surround today’s news stories.
The origins of climate science go back to the late 18th and 19th century interest in the study of glaciers. Already in the 1770s a Swiss scientist, Horace-Bénédict de Saussure, suggested that the atmosphere is like a greenhouse, protecting both the earth’s surface and those who live on it from extreme temperatures. Later John Tyndall , one of the great British scientists of the 19th century, was the first person to do experiments that confirmed the greenhouse effect. But in the 19th century, the term “greenhouse effect” was not synonymous with global warming. Instead, the few scientists who worried about climate change feared an opposite course: global cooling and the return of an ice age that could threaten civilization.
In 1894, Svante Arrhenius, a Swedish chemist, followed Tyndall with calculations showing the effects of carbon dioxide (CO2) on the temperature of the atmosphere. But, unlike current concerns regarding climate change, Arrhenius welcomed the idea of a warming, as he thought it would improve both the weather and agriculture in Scandinavia. As the 20th century progressed, other researchers such as Guy Callendar supported Arrhenius’ findings and attempted to refine the scientific understanding of the role carbon dioxide plays in climate change. Yet Callendar’s arguments were not taken very seriously. In 1951, a prominent climatologist wrote that the CO2 theory of climate change “was never widely accepted and was abandoned.”
It was in the 1950s that modern climate science was actually born. Beginning with work on temperatures across different layers of the ocean, the oceanographer Roger Revelle and his colleagues at the Scripps Institution of Oceanography made decisive contributions to the field. These scientists were intent on better understanding not only weather, but also climate. These models also suggested that human activities played a significant role in causing such change by releasing CO2 into the atmosphere through combustion of hydrocarbons.
By the late 1960s, some discussion was beginning in political circles about climate change. In 1969, White House advisor (and later U.S. Senator) Daniel Patrick Moynihan sent a memo to Richard Nixon saying that the President “really ought to get involved” with climate change. By 197o, it had become clear that America was getting more and more filthy. President Nixon issued an executive order that created the Environment Protection Agency (EPA). The same year, congress and Nixon passed the Clear Air Act, a landmark legislation that helped radically reduce airborne pollutants worldwide.
In 1985 a group of scientists discovered that the atmospheric layer made up of ozone, which protects the earth from solar radiation, had a “hole”. This was an area the size of Antarctica that drastically thinned each spring, letting in high levels of radiation that can cause cancer and contribute to Global Warming.
In 1987 the Montreal Protocol was approved by most nations to phase out the use of ozone-depleting substances.
A milestone in the history of the climate change debate occurred in 1988, when the Intergovernmental Panel on Climate Change (IPCC) was established. This international network of scientists from around the world issues regular reports that synthesize current climate science research.
In 1997 mandatory international limits on greenhouse gas emissions were set in the Kyoto Protocol, which the US refused to sign on; stirring up a storm of controversy.
Over the past two decades, scientific consensus about the reality of climate change has generally solidified, although dissent does remain. In Europe, the European Union has adopted goals of significantly reducing carbon emissions. In the United States, efforts to get an overall national policy on climate change have so far failed. But other policies—such as renewable fuel requirements for electric utilities and new automobile fuel efficiency standards—seek to limit carbon emissions. And recently, public opinion in the United States has moved on climate change as well. According to a Pew Research Center study published in October 2012, about two-thirds of all Americans agree that there is “solid evidence” that the earth is warming. Today, the discussion around climate change has shifted from “Is it happening?” to “What is the extent of human impact?”—and “What should we do about it? A poll published last week revealed that 77% of Americans think the government should be taking actions to curb global warming. However the support was greater among Democrats (90%) and Independents (78) than Republicans (48%). In my next post I will elaborate on why people view climate change differently depending on their political affiliation.