Carbon is the basis for all life on earth. This essay will explain the role of carbon dioxide in various parts of the carbon cycle. This essay will examine two main, and important parts of the carbon cycle, starting by explaining the role of the ocean in absorbing carbon. Next this essay will examine the human influences on the carbon cycle and human production of carbon dioxide. Thirdly this essay will explain what controls thecarbon dioxide concentration.
The ocean holds a vast amount of carbon. Carbon dioxide in the atmosphere is transferred into and out of the ocean continually, maintaining a balance by dissolving in cold polar water. Plankton also play a large role in maintaining a carbon balance. Plankton in the world oceans use carbon dioxide for growth (photosynthesis). Waste organic matter sinks down from these ecosystems, carrying carbon and nutrients away from the surface. Ason land, changes to either components of the ocean carbon cycle, chemical or biological, have a great potential to modify climate change. Scientists believe that the ocean currently absorb 30-50 per cent of the carbon dioxide produced by the burning of fossil fuel. If they did not soak up and carbon dioxide, atmospheric carbon dioxide levels would be much higher then the current level of 355 parts per million by 2050.
The concentration of atmospheric carbon dioxide has been driven upwards over the last 150 years by humans activities. Carbon emissions from the U.S. are now estimated at 1.4 billion tons per year (that’s 5.4 tons per person!)2 Recall that northeastern forests alone contain about five times that amount in wood and biomass, and you begin to appreciate their significance on global budgets.
There are two ways in which we affect the carbon cycle. First we add new atmospheric carbon dioxide into the mix. Power generation and other fossil fuel emissions release about 6 billion tons of carbon per year, would wide, to the atmosphere. Compared to the amount added naturally every year, approximately 100 billion tons3, our contribution is small. However, the new carbon is remaining and accumulating in theatmosphere.
Second, land use changes are converting forested systems, which are carbon sinks, into agricultural and urban zones, which tend to be carbon source. For example, tropical forests losses are estimated to add 1 billion tons of carbon per year4. Perhaps more important, the opportunity to remove carbon dioxide from the atmosphere is greatly reduced when the forests disappear.
Will, George F. “Electronic Morphine.” Newsweek 25 Nov. 2002: 92.
Randall, John E., Gerald R. Allen, and Roger C. Steene. Fishes of the Great Barrier Reef and Coral Sea.
Honolulu: U of Hawaii P, 1997.