Alaska Science Forum

The world's air now is increasing its carbon dioxide content by about 1 percent per year. If the trend continues another decade or so, we may be headed rapidly into climatic change that will increase the world's deserts and reduce the areas suitable for agriculture.

Carbon dioxide, unlike its deadly sound-alike carbon monoxide, is a harmless minor constituent of air (0.03%). Most of the world's carbon is locked up either in carbon dioxide (C0₂) molecules or in rock and mineral compounds.

In sunlight, green plants photosynthesize water and C0₂ from the air into starches and sugars required for plant growth. Sooner or later the C0₂ is returned to the air by the plants themselves or by the bacteria, yeasts and animals that consume the plants as foods. Another way for the so-called biological "carbon-cycle" to be completed is through combustion, either slow (rot) or fast (fire).

Just in the last few years, scientists have come to realize that living plants and humus matter are a major reserve of C0₂, in addition to the huge store in fossil fuels. Fear is being expressed that the clearing of forested land, especially in the tropical rain forests, may be releasing huge amounts of carbon dioxide to the air each year. As man both burns fossil fuels and clears the forests, the air receives a double-barreled insult that it may not be able to cast off. Increased C0₂ in air leads to increasing absorption of infrared light to cause a greater greenhouse effect and consequent climatic changes.

Even the ice pack on the polar seas may be a source of carbon dioxide to the atmosphere. New measurements of carbon dioxide at Point Barrow and offshore have been reported by the University of Alaska's Tom Gosink. These results lead him to think that the sea ice helps transfer C0₂ in sea water to the air more rapidly than it would if the ice were absent. Maybe his idea will provide the world with a safety valve. If the world gets too hot because of increasing C0₂ in the air, perhaps the polar ice will melt and reduce the upward flow of C0₂ to the air and thereby allow a return to normal.