A Brief History of Global Warming
April R. Baumgartner
Earth's climate constantly changes, and many scientists believe that the temperature rises we see in this decade are a natural phenomenon that occurs every so many years. Around 25,000 years ago, it is believed that earth was covered by large areas of ice. And then, about 7,000 years ago, temperatures began to rise and the "Ice Age" came to an end.
Second Ice Age
In the 14th century earth experienced the start of another Ice Age where much of the land mass was covered by glaciers, mostly in three areas: Alaska, Iceland, and the Scandinavian countries. By 1850, however, earth's temperatures had warmed to the point where the glaciers receded, uncovering millions of acres of fertile soil. Jean Baptiste Joseph Fourier, a French mathematician, was the first scientist to propose a theory of global warming. In 1824 he discovered the the earth's temperature was slowly rising. His theory was labeled the "greenhouse effect" because carbon dioxide traps heat inthe earth's atmosphere. Fourier's theory was challenged by Mulutin Milankovitch, who proposed the earth's changing temperatures were nothing more than a result of orbital changes of earth.But again in the 1950s, G.S. Callendar supported Fourier's greenhouse effect, and his work led others to increase their reserach effortts into the concept of global warming. Over 20 mathematical models have been used to analyze global temperatures, and these findings support a belief that global warming is directly related to human activity. It was at that time that scientist voiced their opinion that anincreased level of carbon dioxide emissions would trigger an outbreak of global warming. The fear that carbon dioxide emissions were responsible for an increase in global temperatures prompted the internaional community to propose the creation of the Kyoto Protocol, an international agreement to fight global warming.