Carbon Busting
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Virtually all climate scientists agree that the earth's climate is warming, and that excess carbon, in the form of carbon dioxide, is to blame. Vegetation can slow warming by taking carbon dioxide out of the atmosphere but are there limits to what vegetation can absorb?

I'm Dave Thurlow, and this is The Weather Notebook.

Researchers at the Hadley Centre for Climate Prediction and Research, in England, have developed a model to assess the role that trees, grass, and shrubs can play in limiting the amount of carbon dioxide, or CO 2, in the atmosphere. Roughly speaking, the less CO2, the less warming of the atmosphere. And vegetation, as a part of its life cycle, absorbs and stores CO 2. Thus, conventional wisdom suggests that a preponderance of vegetation will help us meet our goals in calculating the earth's "carbon budget" a budget where more CO 2 absorbed means a more slowly warming earth.

The results of the Hadley Centre study, though, are not very encouraging. Taking a close look at the feedback of the atmosphere and vegetation, the researchers have suggested that there are limits to the ability of earth's vegetation to absorb carbon. As the earth warms, vegetation reaches a point where carbon absorption plateaus . Our greenery can only make use of so much CO 2; the rest will remain in the atmosphere. Meanwhile, the emission of CO2 by microorganisms in the soil increases steadily. The end result of the Hadley Centre model is lots of CO 2, and more warming than most other climatic models predict.

Other researchers note that the Hadley Centre results are somewhat extreme; still, they force us to take a closer look at our "carbon budget", and challenge us to develop safer strategies for our climate future, then simply business as usual.

Today's writer is Peter Crane and our engineer is Sean Doucette. The Weather Notebook is a production of the Mount Washington Observatory, North Conway New Hampshire.