Key Category Analysis Tool (U.S. EPA Toolkit for Building National GHG Inventory Systems)

Developing a greenhouse gas (GHG) inventory is an important first step toward managing emissions. A complete and transparent national GHG inventory is an essential tool for understanding emissions and trends, projecting future emissions and identifying sectors for cost-effective emission reduction opportunities. A national GHG inventory is also a core element of reporting under the United Nations Framework Convention on Climate Change (UNFCCC).

The U.S. EPA Toolkit for Building National GHG Inventory Systems (“Toolkit”) is intended to help national inventory compilers build and advance a national GHG inventory system that suits their national context. It includes pre-defined National System Templates. Completed templates (adapted to reflect national context) can be compiled into a single National GHG Inventory System Manual, which provides a comprehensive documentation of each critical component for managing the GHG inventory development process.

The resources in the Toolkit have undergone several revisions since their initial development, including recent updates in 2020, and are consistent with Intergovernmental Panel on Climate Change (IPCC) “good practice,” the 2006 IPCC Guidelines for national GHG inventory development, and the latest UNFCCC transparency requirements.

The Key Category Analysis Tool enables a GHG inventory team to determine key categories of GHG emissions and removals from GHG inventory estimates. It can be used in conjunction with the Key Category Analysis template which identifies the sources and sinks that make the greatest contribution to national GHG emissions and removals. With this analysis of key categories, a GHG inventory team can prioritize over time the resources needed to implement the more impactful improvements to a national GHG inventory.