Nearly 239 million hectares (590 million acres) of land in the United States are devoted to pastures and rangeland. Worldwide, rangelands cover about 3.6 billion hectares (8.9 billion acres). Harnessing the potential for carbon sequestration from these lands could have a global impact on reducing greenhouse gas emissions.
The current issue of the journal Rangeland Ecology & Management examines carbon sequestration in western U.S. rangelands from an economic perspective. It finds that revenues from voluntary carbon offset programs are not likely to generate enough incentive to encourage participation from rangeland managers.
Soil organic carbon in rangelands can contribute to the environment in positive ways. Increased carbon can reduce erosion and improve soil quality, soil water-holding capacity and nutrient cycling. Although the potential for carbon sequestration on rangelands is lower than that of agricultural and forest lands, modest changes in carbon storage on rangelands hold promise to affect the carbon cycle worldwide.
Activities such as adjusting stocking rate, interseeding alfalfa, burning, fertilizing and restoring degraded pastures can improve carbon sequestration on rangelands. Like agricultural commodities, however, carbon yields and carbon credit prices can vary widely from year to year. On the other hand, climate exchange contracts can run from five to 100 years, introducing another element of risk to rangeland carbon sequestration.
Carbon offset programs, such as the Chicago Climate Exchange, offer voluntary trading of carbon credits based on a cap-and-trade system. Farmers, ranchers and foresters who conduct mitigation practices on their lands have been included in these offset programs. However, these programs have seen a downturn during the global financial crises.
This study estimated revenues for both short-term voluntary offsets and 100-year offsets that meet international standards. Prices were projected based on potential cap-and-trade legislation and on historical data. This simulation found that the carbon market does not yet offer a sufficient return on investment for rangeland managers to adopt practices that improve carbon sequestration.
Full text of the article, "Profitability of Carbon Sequestration in Western Rangelands of the United States," Rangeland Ecology & Management, Vol. 65, No. 4, 2012, is available at www.srmjournals.org/doi/full/10.2111/REM-D-10-00191.1.