New model revises estimates of terrestrial carbon diox...( Researchers at the University of Ill...)

Researchers at the University of Illinois have developed a new model of global carbon and nitrogen cycling that will fundamentally transform the understanding of how plants and soils interact with a changing atmosphere and climate.

The new model takes into account the role of nitrogen dynamics in influencing the response of terrestrial ecosystems to climate change and rising atmospheric carbon dioxide.

Current models used in the assessment reports of the Intergovernmental Panel on Climate Change do not account for nitrogen processing, and probably exaggerate the terrestrial ecosystems potential to slow atmospheric carbon dioxide rise, the researchers say. They will present their findings this week at the annual meeting of the American Geophysical Union in San Francisco.

In the face of global climate change, world leaders are in need of models that can reliably predict how land use and other human activities affect atmospheric carbon dioxide levels. Deforestation and the burning of coal and oil increase atmospheric carbon dioxide and contribute to global warming.

Growing plants take carbon dioxide from the air and store it as carbon in their tissues. This means that plant growth especially that of trees can help reduce the effects of rising carbon dioxide levels, which contribute to global warming.

Scientists have struggled for decades to build computer models that accurately predict how plants and soils will respond to rising carbon dioxide levels in the atmosphere.

In the 1990s, researchers reported that crop plants such as cotton or wheat are more productive when exposed to higher carbon dioxide levels. This fertilization effect increases CO2 uptake and was hailed by some as evidence that Earths forests also would take up more carbon dioxide as atmospheric levels increased.

But models of the carbon cycle have failed to take into account how nitrogen availability influences this equation on
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