Pollution can affect climate. As a result of air pollution, the atmosphere has more haze and more clouds than it once had. The large amount of condensation nuclei added to the atmosphere by smoke probably causes some of the haze and clouds. Water vapor and clouds can affect the climate of the Earth in different ways. Clouds reflect radiant heat from the sun back into space, producing a warmer climate.
Carbon dioxide in the atmosphere has an important effect upon climate. Radiant heat from the sun readily passes through the atmosphere on the way to the Earth’s surface. When the Earth reradiates this heat back toward space, the carbon dioxide acts like the glass of a greenhouse to prevent the heat from escaping.
A small increase in the amount of carbon dioxide in the atmosphere could raise the Earth’s temperature to melt the polar ice caps. The water released could raise the level of the oceans by as much as sixty feet, flooding many coastal areas. Billions of tons of carbon dioxide are produced by respiration in animals and by combustion of coal and oil each year. The carbon dioxide may stay in the atmosphere for several years before it is absorbed by ocean organisms or green plants and converted back into carbon compounds and oxygen.
The most common and widespread pollutants currently emitted by human activities are sulfur dioxide, nitrogen oxides, carbon monoxide, carbon dioxide, volatile organic compounds, particulates or tiny solid particles or liquid droplets, and lead. In addition, dozens of toxic chemicals are commonly found in the air surrounding urban areas.
Air pollution, damage to living organisms, and global climate change are complex and diverse problems. Yet they all share a common root called energy consumption. To slow damage to plants and animals and to avoid destructive climate, change will require fundamental changes in energy policy.