Published: August 04, 2005

Carbon Dioxide to overwhelm Earth Storage Capacity

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The Earth's various sources and sinks for carbon. The land and oceans can absorb some of the increased carbon from fossil fuel emissions, but as the emission rate increases, these sinks saturate and become less effective at removing carbon from the atmosphere.
Graphics by Inez Fung/UC Berkeley.

According to a report from Berkeley University, a new generation of computer climate models indicates there are limits to the planet's ability to absorb increased emissions of carbon dioxide. The new computer model includes the effects of Earth's carbon cycle.

The climate modeling study was published this week in Proceedings of the National Academy of Sciences by Inez Y. Fung and colleagues.

"Currently, the land and oceans absorb about half of the carbon dioxide produced by human activity, most of it resulting from the burning of fossil fuels", Fung said.

Some scientists have suggested that the land and oceans will continue to absorb more and more CO2 as fossil fuel emissions increase, making plants flourish and the oceans bloom.

Fung's computer model, however, indicates that the "breathing biosphere" can absorb carbon only so fast. Beyond a certain point, the planet will not be able to keep up with carbon dioxide emissions.

"The reason is very simple," Fung said. "Plants are happy growing at a certain rate, and though they can accelerate to a certain extent with more CO2, the rate is limited by metabolic reactions in the plant, by water and nutrient availability, et cetera."

For more information, read the Press Release.