(113) The two gases that make up most of our atmosphere, oxygen and nitrogen, do not absorb much light in either the visible or the infrared range. Carbon dioxide and other infrared-absorbing gases let visible light come through but trapped heat-producing infrared light. In 1896, the Nobel Prize–winning Swedish chemist Svante Arrhenius turned his attention to understanding what might have caused the ice ages that have come and gone throughout the earth’s geologic past. Fossil records showed that ice covered the earth as far south as Germany and Illinois as recently as 12,000 years ago. Drawing on Tyndall’s and Fourier’s discoveries, Arrhenius proposed that carbon dioxide released by ancient volcanoes resulted in the earth growing 20–30°C (68–86°F) warmer as a result of the greenhouse effect. He theorized that the decrease of carbon dioxide in the atmosphere between periods of volcanic activity resulted in the cooling periods that brought on the ice ages.
Posted on: Tue, 16 Dec 2014 09:18:21 +0000
Trending Topics
Recently Viewed Topics
© 2015