Time Magazine Monday, May. 28, 1956
Since the start of the industrial revolution, mankind has been burning fossil fuel (coal, oil, etc.) and adding its carbon to the atmosphere as carbon dioxide. In 50 years or so this process, says Director Roger Revelle of the Scripps Institution of Oceanography, may have a violent effect on the earth’s climate.
Tons of CO2. The temperature of the earth’s surface depends largely on two minor constituents of the atmosphere: water vapor and carbon dioxide. They are transparent to the short-wave energy (light and near infrared) that comes from the sun, but opaque to most of the long-wave heat radiation that tries to return to space. This “greenhouse effect” traps heat and makes the earth’s surface considerably warmer than it would be if the atmosphere had no water vapor or carbon dioxide in it. An increase in either constituent would make it warmer still. Warm eras in the geological past may have been caused by CO2 from volcanoes.
At present the atmosphere contains 2.35 trillion tons of carbon dioxide, existing in equilibrium with living plants and sea water (which tends to dissolve it). Up to 1860, man’s fires added only about 500 million tons per year, and the atmosphere had no trouble in getting rid of this small amount. But each year more furnaces and engines poured CO2 into the atmosphere. In 1900, the amount was 3 billion tons. By 1950, it was 9 billion tons. By 2010, if present trends continue, 47 billion tons of carbon dioxide will enter the air each year.