Cities test new toolkit to improve quality of GHG emission inventories

By Molly Wang, Technical Assistance Project Manager at C40

A new C40 toolkit is now available to help cities improve the quality of community wide greenhouse gas (GHG) emission accounting and reporting. It aims to guide practitioners through the process of assessing whether their emission inventories have followed the requirements and principles of the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories (GPC), a best practice standard used by cities across the globe to measure and report GHG emissions in a comprehensive and consistent manner. 

Inventory specialists from Auckland, Austin, Cape Town, Mexico City and San Francisco tested the GPC Self-verification Toolkit on their latest GHG inventories, and worked closely with C40 to ensure the toolkit is user-friendly and meets the needs of cities. 

Through the testing, city experts also identified opportunities to strengthen their inventories.

“It has allowed us to improve the quality control, give transparency and find omissions in our draft inventory,” said Patricia Camacho, Director of Emissions Inventories and Air Quality Programs in Mexico City. “This enhanced our internal review process and gives us more confidence in making the new inventory public through the Carbon Disclosure Project.”   

Besides internal reviews, the toolkit has been designed to facilitate peer to peer reviews as well. “Having another city to look at your inventory reduces biases and adds to the transparency and confidence,” said Brian Reyes from San Francisco’s Department of Environment, who worked with the City of Austin during the review process.

“It was also helpful just to see how another city has put together their inventory, like what data sources and methodologies they’ve used – as well as some data challenges we shared,” said Cavan Merski, from Austin’s Office of Sustainability.

Both representatives from Austin and San Francisco agreed that thanks to the step-by-step process of the toolkit, they were able to identify certain adjustments to be made to their inventories that they wouldn't have picked up on otherwise.

The toolkit also features a simple benchmarking function to compare with GPC inventories already made available by over 50 C40 cities. “Benchmarking is useful for climate action thinking,” said Dr. Shanju Xie from the Research & Evaluation Unit (RIMU) at Auckland Council. “You can compare not only the emission profile but also the historic trend of emissions in your city to others with similar economic and climate conditions.”

This toolkit forms part of the broader C40 Climate Action Planning Technical Assistance Programme that aims to build capacity within cities to develop robust and ambitious climate action plans.

“Taking action on climate change needs to be based on a good understanding of energy use and GHG emissions across the city,” said Sarah Ward, Head of Energy and Climate Change in the City of Cape Town. “Developing emission inventories on a regular basis is essential for tracking performance of climate actions, and this toolkit could be of benefit to our future inventory updates and reviews by ensuring consistent quality improvements.” 

The GPC Self-verification Toolkit can be downloaded here, together with existing tools and resources available from C40, including the City Inventory Reporting and Information System (CIRIS), a tool for managing and reporting city GHG inventory data. The GPC Self-verification Toolkit is best suited to assess inventories reported using CIRIS or its predecessors, but can be adapted to other reporting formats too.

Feedback and recommendations for future improvement are always welcome.