Author
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Idso, Sherwood |
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Submitted to: Nature
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/1/1999 Publication Date: N/A Citation: N/A Interpretive Summary: What will be the long-term consequences of the ongoing rise in the carbon dioxide content of the atmosphere for earth's long-lived trees and shrubs? Data that appear in the peer-reviewed scientific literature are used to demonstrate that the initial large growth stimulation typically provided by atmospheric CO2 enrichment gradually declines with time, quite rapidly at first, but then ever more slowly. For three important studies of loblolly pine, sour orange and evergreen oak trees published in 1997, for example, there is a 90 percent increase in standing biomass after five years of exposure to an extra 300 ppm of CO2, which declines to approximately 25 percent after 30 years but probably still hovers somewhere in the vicinity of 10 percent after a full century. This finding represents a compromise between the two extreme views that have prevailed to this time: a large sustained response that persists indefinitely and a more moderate response that totally disappears after a few years. This observation should help policy makers to better plan for future global change induced by the rising CO2 content of the earth's atmosphere. Technical Abstract: What will be the long-term consequences of the ongoing rise in the carbon dioxide content of the atmosphere for earth's long-lived trees and shrubs? Data that appear in the peer-reviewed scientific literature are used to demonstrate that the initial large growth stimulation typically provided by atmospheric CO2 enrichment gradually declines with time, quite rapidly at first, but then ever more slowly. For three important studies of loblolly pine, sour orange and evergreen oak trees published in 1997, for example, there is a 90 percent increase in standing biomass after five years of exposure to an extra 300 ppm of CO2, which declines to approximately 25 percent after 30 years but probably still hovers somewhere in the vicinity of 10 percent after a full century. This finding represents a compromise between the two extreme views that have prevailed to this time: a large sustained response that persists indefinitely and a more moderate response that totally disappears after a few years. This observation should help policy makers to better plan for future global change induced by the rising CO2 content of the earth's atmosphere. |
