Novel Approach to Consumption-Based Greenhouse Gas Emissions Inventories for States

Traditional greenhouse gas (GHG) inventories track the emissions that occur within a region’s borders (often referred to as territorial emissions). However, additional emissions created during production and distribution of goods and services can occur outside those borders. Accurately accounting for those external emissions, which requires consideration of emissions associated with consumption of goods and services, is integral to understanding the complete picture of emissions within the purview of a region, state, or country.

ERG, in support of the U.S. Environmental Protection Agency (EPA), developed a novel approach for using the USEEIO model to assess consumption-based emissions inventories (CBEIs) at the state level. A CBEI provides information on annual GHG emissions created when producing goods and services consumed by residents of a particular region, such as a state, regardless whether the goods and services were produced within or outside the region. We then used this novel approach to assess consumption-based emissions for each of the six northeastern U.S. states. We found that the consumption-based emissions for all six northeastern U.S. states are 40 to 60 percent greater than their territorial emissions. EPA published our methodology and CBEI results in a report. In addition, we created an open-source tool to enable development of a streamlined CBEI report for each of the 50 states. This tool can be updated in the future as new emissions and economic data become available, enabling rapid assessment of progress toward achieving GHG goals.