Greenhouse gas (GHG) emissions are commonly estimated at global, national, and perhaps state-level scales. As part of a NASA and NIGEC funded project on Global Change in Local Places (GCLP), GHG emissions for 1990 (carbon dioxide, methane, and nitrous oxide) were determined for 45 counties in western Kansas. The EPA method for state-level GHG estimation was modified for use at the county scale. Data inputs to the estimation included: U.S. Census data (for emissions related to human population), U.S. Census of Agriculture data (primarily animal emissions), Kansas Department of Transportation data (transportation emissions), and EPA Aerometric Information Retrieval System (AIRS) data (industry reported emissions).
Even though the overall GHG emissions per square kilometer are lower than state or national averages, GHG emissions vary considerably across western Kansas. County-to-county variations in methane range over two orders of magnitude with maximum values in excess of 20,000 tons of equivalent carbon dioxide for counties with a concentration of feedlots. County level carbon dioxide emissions vary by three orders of magnitude. Maximum carbon dioxide emissions occur in the Hugoton Gas Area, where some of the natural gas resource is used in large compressor engines to push gas through interstate pipelines toward northeastern markets. While considerable variation also exists in nitrous oxide emissions, the relative contribution of this GHG is small. Total GHG emissions exceed one million tons of equivalent carbon dioxide per year in some counties and are less than 150,000 in others. The paper concludes with a discussion of the implications of this local variability for development of a national emissions reduction strategy