Potential for enhanced sequestration of carbon in soils supports evaluations

A group of researchers led by Wilfred M. Post of the Oak Ridge National Laboratory describes in the October 2004 issue of BioScience an approach to assessing "promising" techniques for mitigating global warming caused by the greenhouse effect. According to Post's team, agriculturally based options for reducing net greenhouse gas emissions by increasing sequestration of carbon in soils "should be evaluated to see how competitive they are in comparison with a variety of other options," such as flue-gas capture to reduce emissions or remove carbon dioxide already in the atmosphere.

Post and his colleagues considered the range of possible costs and benefits that could accrue from adopting land-management practices designed to increase the uptake of carbon dioxide by soils. The increasing concentration of carbon dioxide in the earth's atmosphere contributes to ongoing global warming that is causing ecological disruption and threatens human populations.

The researchers note that a variety of land-use practices have apparently favorable potential for increasing carbon dioxide uptake, including intensifying cropping, adding organic material to soil, conservation tillage, and afforestation and grassland establishment. Initial cost estimates of some of these practices appear low, but many other considerations must be weighed before the techniques are likely to come into widespread use, including the likely permanence of soil carbon sequestration by different methods. Assessment of ancillary environmental effects, such as impacts on biodiversity and emissions of other greenhouse gases, is necessary, as are sensitivity analyses to determine likely consequences over the range of applicable conditions.

Comprehensive economic comparisons are also called for. Post and colleagues state that "If agricultural soil sequestration is to play a role in the endeavor to reduce greenhouse gas emissions, it is important both to determine that soil sequestration practices are competitive, low-cost means of offsetting greenhouse gas emissions and to design programs or incentives that make these practices attractive for use by land managers."

Journalists may obtain copies of the article, "Enhancement of Carbon Sequestration in US Soils," by contacting Donna Royston, AIBS communications representative. BioScience publishes commentary and peer-reviewed articles covering a wide range of biological fields, including ecology. The journal has been published since1964. AIBS is an umbrella organization for professional scientific societies and organizations that are involved with biology. It represents over 80 member societies and organizations with a combined membership of over 200,000.

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