Carbon Sequestration, Greenhouse Gas Emissions, and Nebraska Agriculture – Background and Potential

Scientists believe that rising levels of carbon dioxide and other greenhouse gases are contributing to global warming, although to what extent is difficult to determine. While limiting fossil fuel consumption is one method of reducing emissions of carbon to the atmosphere, another is sequestering carbon sources on the land. Carbon sequestration is the use of practices, technologies, or other measures that increase the retention of carbon in soil, vegetation, geologic formations, or the oceans with the effect of offsetting carbon dioxide emissions from other sources. Nebraska’s agricultural producers can help address greenhouse gas concerns by implementing practices that cause the land to act as a sink for carbon, by decreasing emissions of greenhouse gases from agricultural production activities, or by participating in other activities such as biofuels production (which can provide a substitute for fossil fuel use). Many of the activities that increase the organic content of soils, and thus sequester carbon, also increase agricultural productivity as well as improve soil, air and water quality. With Nebraska’s large agricultural land base, the state’s landowners could potentially profit from carbon sequestration if certain types of carbon trading or other financial incentives are put in place. Yet there are very significant questions about whether substantial carbon trading markets will develop in the United States and, if so, what form they might take. At this point in time there has been no federal government action that would result in development of strong carbon markets in this country. An agreement on rules for implementing an international agreement, the Kyoto Protocol to the United Nations Framework Convention on Climate Change, was reached in Marrakech, Morocco in November 2001. The agreement would restrict future greenhouse gas emissions by industrialized countries and provide for trading of credits by countries to offset greenhouse gas emissions. However, the Protocol has not yet been ratified by the requisite number of nations for it to take effect and is opposed by the President of the United States. Would the United States be able to participate in the potential resulting carbon market if it was not party to the Kyoto Protocol? International developments bear monitoring as they continue to unfold. The United States currently contributes over 18% of the world’s emissions of the three major greenhouse gases in global warming potential, while only having about 5% of the world’s population. U.S. Department of Agriculture estimates have indicated that cropland has the potential to sequester about 154 million metric tons of carbon per year, or about 8.4% of total U.S. emissions. Another source indicates that cropland could sequester as much as 123 to 295 million metric tons annually, including potential offset from use of biofuels, reduced fuel usage, and reduction of eroded sediments. Nebraska cropland management practices currently sequester about 1.7 million metric tons of carbon per year. It is estimated that this level of sequestration can be maintained and increased to 2.3 million metric tons if all cropland is converted to a no tillage management system. Agroforestry in Nebraska has an estimated potential to sequester 82 to 165 million metric tons in carbon storage value at a point 40 years after planting. Forestry in Nebraska has an estimated storage potential of almost 50 million metric tons at that 40-year point