GHG Contribution Analysis Toolkit Released

Share on facebook
Share on twitter
Share on linkedin

Contribution analysis results for City of Aspen, CO for their 2011 and 2014 inventories

ICLEI – Local Governments for Sustainability USA released today a new methodology to measure performance in greenhouse gas inventories by analyzing major external factors that determine year-to-year results.

Supported by financial assistance from the U.S. Department of Energy’s Cities Leading through Energy Analysis and Planning (Cities-LEAP) project and led by the City of Bellevue, Washington, ICLEI-USA developed the new methodology in partnership with a steering committee of the following communities and regions:

Aspen, Colorado;
Bellevue, Washington;
Delaware Valley Regional Planning Commission
King County, Washington;
Santa Monica, California;
Metropolitan Washington Council of Governments

An additional group of pilot communities contributed to the testing of the methodology and toolkit:

Ashland, Oregon;
Cleveland, Ohio;
Denver, Colorado;
Durham, North Carolina;
Hayward, California;
Miami-Dade County, Florida;
Olympia, Washington;
Nashville, Tennessee;
Shoreline, Washington

The methodology, referred to as the contribution analysis or decomposition analysis, was informed by the Steering Committee and tested by a dozen additional communities. Now available in a toolkit and guidance document, the method allows any city, county, or region to evaluate community-wide energy and GHG emissions performance attributable to local climate action. This enhanced view results in a deeper understanding of the actions that drive emissions changes, resulting in an ability to better prioritize future actions based on past performance.

Key Outcomes:

  • Excel-based analysis tool and data check list
  • Full length guidance document for understanding the contribution analysis theory and navigating the tool
  • Quick start guidance document for using the tool and finding data
  • Standard waterfall graphs for visualizing the drivers of emission changes
  • Online trainings and recommended data sources for using the contribution analysis toolkit
  • Case study publications for steering committee cities on their analyses

For more information, visit


“The contribution analysis shows the importance of switching to cleaner fuel sources and reducing VMT (vehicle miles traveled) per person in overall emissions reductions. Energy, land-use, and transportation planning are key focus areas of the Council of Governments’ overall work.”
– Metropolitan Washington Council of Governments (Washington, DC):

“Good GHG data is foundational to our climate action planning work and realizing progress towards Aspen’s community-wide goals. The ‘decomposition analysis’ provides our community with both granular and actionable insights that our previous GHG analyses had not revealed. Moving forward, Aspen will use these additional insights to inform climate action that is more targeted and more effective. This is a natural and needed evolution in the practice.”
– City of Aspen, Colorado

“The contribution analysis toolkit allows for quick and easy analysis of the multiple factors driving changes to greenhouse gas emissions from one period to another. Furthermore, the toolkit boils down the varying impacts of all these factors into one easy-to-understand graphic.”
– Delaware Valley Regional Planning Commission

“Seeing what factors impact your emissions is powerful. This project opens up the ‘black box’ of GHG inventories. It helps agencies to focus on the areas they can affect the most.”
– City of Santa Monica, California


Share on facebook
Share on twitter
Share on linkedin

See More from ICLEI