• Decarbonization
  • Sustainability
  • Emissions Reductions
  • Greenhouse Gas Emissions

Raising the Bar for City Greenhouse Gas Accounting and Reporting

Véronique Vera
Jul 29, 2021

Guidehouse Insights

This blog was coauthored by Madeleine Hardy and Oskar Krabbe.

Cities are increasingly taking the lead in driving decarbonization globally. Initiatives such as the Global Covenant of Mayors for Climate & Energy, C40 Cities Climate Leadership Group, and ICLEI – Local Governments for Sustainability promote climate action in cities; and CDP offers a global platform for cities to disclose their climate performance.

Greenhouse gas (GHG) reporting for cities is complex and poses challenges not seen in corporate reporting:

  • Cities have more complex emission sources than most corporates (e.g., waste, agriculture; see figure below), requiring a broader range and more elaborate GHG calculation methodologies. 
  • A city’s scope 3 emissions are difficult to define. This includes emissions that occur outside of city borders as a result of activities occurring within them (e.g., residents booking flights from a neighboring airport). Double counting between emissions from energy production (scope 1) and energy consumption (scope 2) is also a challenge at the city level. 
  • City GHG accounting requires vast amounts of footprint data, which are largely collected from external sources and stakeholders (e.g., service providers, product suppliers, inhabitants, and national, regional, and local governments). Frequently, a substantial share of required information is not readily available and needs to be filled using assumptions.
  • Most cities report annual emissions with a few years delay and tend to report less frequently if they have a broader scope due to the challenging and time-consuming nature of GHG accounting and reporting. They also frequently use spreadsheets to model their GHG footprint, which is inefficient and error prone. 

Sources and Boundaries of City GHG Emissions

Sources and Boundaries of City Greenhouse Gas Emissions

(Source: Global Protocol for Community-Scale Greenhouse Gas Emission Inventories)

GHG accounting and reporting standards for cities are evolving to address these challenges, but there are limitations. The GHG Protocol for Cities (GPC) defines different reporting frameworks—BASIC, BASIC+, and territorial (total scope 1, aligned with Intergovernmental Panel on Climate Change)—and notes that reporting other scope 3 emissions and local government emissions is optional. PAS 2070 aligns with GPC, with the added guidance to calculate emissions from goods and services (mostly scope 3 sources such as imported food and drink, water, and construction materials). Cities report some of these sources following the consumption-based methodology, which estimates emissions from imported goods using a top-down approach based on statistics. 

However, having all these options makes the reporting process more complex and the consumption-based method has its limitations. It lacks granularity as it relies on regional or national financial data and is unable to capture any progress on city level as a result. A hybrid approach that uses available data on physical imports solves some of these issues, but the increased complexity can be challenging to manage with the existing spreadsheet-based methods. The following figure emphasizes the GHG reporting frameworks cities can follow and how they could cover their full emissions scope.    

City GHG Footprint Reporting Frameworks

City Greenhouse Gas Reporting Frameworks

(Source: Guidehouse)

Guidehouse’s GHG sustainability management platform Papaya™ helps cities develop a world-class GHG inventory and facilitates automation. This digital solution:

  • Improves data collection by allowing stakeholders to enter data directly in the system or by integrating with existing data systems (e.g., SAP) or IoT devices (e.g., energy meters). 
  • Uses physical data when available and financial data for the rest, so that cities can account for all scope 3 emission sources and more accurately measure consumption-based emissions. 
  • Automates reports for various city GHG reporting frameworks, making it is easy to report frequently and without delay, and to use real-time data for emissions monitoring.

Guidehouse is raising the bar in calculating community GHG footprints, allowing cities to capture the full impact of their carbon emissions.