The U.S. Environmental Protection Agency's Agency’s (EPA) Greenhouse Gas Reporting Program (GHGRP) collects and disseminates annual greenhouse gas (GHG) data from individual facilities and suppliers across the U.S. economy. EPA also develops the annual Inventory of U.S. Greenhouse Gas Emissions and Sinks (Inventory) to track total national emissions of greenhouse gases to meet U.S. government commitments to the United Nations Framework Convention on Climate Change. The GHGRP and Inventory datasets are complementary and may inform each other over time. However, there are also important differences in the data and approach. These differences are highlighted here to help stakeholders understand these data sources and use them appropriately.

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• Approach to collecting and reporting data. The U.S. GHG Inventory is largely developed with a "top down" “top down” approach using aggregated national data to develop emissions estimates for the entire U.S. economy. For many sources, the Inventory data cannot be broken down to show emissions by facility. The GHGRP uses a "bottom up" “bottom up” approach. It collects GHG data for every facility and supplier that is required to report, which allows the data to be grouped and categorized in a variety of useful ways including by facility, location, and industry group.

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