ANTHROPOGENIC CARBON SINKS

Reference

Sarmiento, J.L. and N. Gruber. Sinks for anthropogenic carbon,Physics Today, 55(8), 30-36, 2002.
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Abstract
Organic carbon buried in sediments as coal, natural gas, and oil over literally hundreds of millions of years is being consumed by human activities and returned to the atmosphere as carbon dioxide on a time scale of a few centuries. The energy harvested from this transformation of fossil fuels supplies us with electricity, heat, transportation, and industrial power. The clearing of forests for agricultural lands and harvesting of wood, which remove carbon-bearing vegetation, have also added carbon dioxide to the atmosphere, in amounts equivalent to more than half of the fossil fuel source. The carbon dioxide added to the atmosphere by man’s activities, and its current fate, is depicted in the carbon cycle diagram shown in figure 1. Because of anthropogenic emissions, atmospheric carbon dioxide has climbed to levels that are presently more than 30% higher than before the industrial revolution, as seen in figure 2.1,2 Indeed, geochemical measurements made on ancient ocean sediments reveal that atmospheric carbon dioxide levels over the past 20 million years were likely never as high they are today.

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