Intensive Study Who or what is to blame? Scientists conclude that it is the burning of coal, oil, synthetic fuels, and natural gas. These fossil energy sources release an estimated five and a half billion tons of carbon into the atmosphere each year as colorless, odorless CO2 gas
4 Who or what is to blame? Scientists conclude that it is the burning of coal, oil, synthetic fuels, and natural gas. These fossil energy sources release an estimated five and a half billion tons of carbon into the atmosphere each year as colorless, odorless CO2 gas. Intensive Study
Intensive Study 5 The increased carbon dioxide could profoundly affect the way the earth is heated by the sun. The suns energy strikes the earth mainly in the form of visible light. As the earth heats up, it radiates this energy back into space, but at the much longer wavelengths of infrared light, or heat. Carbon dioxide lets the visible light pass through, but absorbs energy at infrared wavelengths. Thus, the more carbon dioxide there is in the atmosphere, the more the earths heat is blocked from escaping- just as a blanket holds in the heat of a sleepers body. In the late 1800s, a Swedish scientist gave this phenomenon its name when he compared it to the way glass shuts in air heated by the sun in a greenhouse
5 The increased carbon dioxide could profoundly affect the way the earth is heated by the sun. The sun’s energy strikes the earth mainly in the form of visible light. As the earth heats up, it radiates this energy back into space, but at the much longer wavelengths of infrared light, or heat. Carbon dioxide lets the visible light pass through, but absorbs energy at infrared wavelengths. Thus, the more carbon dioxide there is in the atmosphere, the more the earth’s heat is blocked from escaping — just as a blanket holds in the heat of a sleeper’s body. In the late 1800s, a Swedish scientist gave this phenomenon its name when he compared it to the way glass shuts in air heated by the sun in a greenhouse. Intensive Study
Intensive Study 6 Some scientists think the greenhouse effect already has begun: Average global temperatures have risen about one degree Fahrenheit in the past ninety years(with a dip from the mid-1940s to 1970). Others argue that the rise could be due to natural temperature ups and downs
Intensive Study 6 Some scientists think the greenhouse effect already has begun: Average global temperatures have risen about one degree Fahrenheit in the past ninety years (with a dip from the mid-1940s to 1970). Others argue that the rise could be due to natural temperature ups and downs
Intensive Study 7 Nevertheless most scientists agree that the accumulation of carbon dioxide has reached the point where an increase in temperature is sure to take place. One study said average global temperatures probably would rise nearly four degrees by the twenty-first century - a total warming greater than that since the last ice age
7 Nevertheless, most scientists agree that the accumulation of carbon dioxide has reached the point where an increase in temperature is sure to take place. One study said average global temperatures probably would rise nearly four degrees by the twenty-first century — a total warming greater than that since the last ice age. Intensive Study
Intensive Study 8 Rising temperatures would be just the beginning. The heating would shift global rainfall patterns, bringing drought to some now-fertile areas and irrigating some deserts. Likewise, mountain glaciers and polar ice caps could melt substantially, causing the seas to rise two feet by the end of the century. many low-lying communities could be flooded. Worst of all, the effect may be irreversible
8 Rising temperatures would be just the beginning. The heating would shift global rainfall patterns, bringing drought to some now-fertile areas and irrigating some deserts. Likewise, mountain glaciers and polar ice caps could melt substantially, causing the seas to rise two feet by the end of the century. Many low-lying communities could be flooded. Worst of all, the effect may be irreversible. Intensive Study