Each signatory country to the United Nations Framework Convention on Climate Change (UNFCCC) is expected to report greenhouse gas (GHG) emissions and sinks, including those occurring in agricultural lands. While many developed countries have reported for agriculture in recent years, few developing countries, including most nations in Central America, have communicated emissions and sinks associated with farming and ranching operations. Using guidelines and methods provided by the Intergovernmental Panel on Climate Change, an assessment tool has been created to conduct national GHG inventories for agriculture, including emissions and sinks related to soil management. Soils are sources and sinks of nitrous oxide, methane and carbon dioxide. To estimate the net fluxes from soils, users enter national-level activity data on land use, management practices, livestock populations, manure management, fertilization practices and lime usage. Emission factors are specified in the next step, and then users can compute emissions and sinks using empirical routines within the assessment tool. Users are prompted throughout this process to complete Quality Assurance/Quality Control procedures as well as given reporting documentation about activity data, emission factors and results. The assessment tool is currently being applied in Central American Nations as step towards improving their national communications to the UNFCCC, and will allow those governments to become more actively engaged in international climate change discussions and mitigation efforts.