Woodcache PBC

Emissions Gaming? A Gap in the GHG Protocol May Be Facilitating Gaming in Accounting of GHG Emissions

Marc Lepere, David Aikman, Yao Dong, Evangelos Drellias, Swarali Deepak Havaldar, Mattias Nilsson
King’s College London
Peer Reviewed: No
Year Published: 2023

Key Takeaways:

  • Average emission factors in the UK-Defra emissions database are ~10% lower than the US-EPA database for the same activity.
  • Companies can select between a variety of approaches when preparing their public-facing emissions disclosures.
  • This creates substantial space for bad actors to under-report their true emissions.
Emissions gaming


The framework for calculating firms’ greenhouse gas emissions via the GHG Protocol is highly complex. It involves the collection and management of large datasets on companies’ activities, and both scientific and estimation uncertainty in translating such activities into emissions estimates. Moreover, there are substantial degrees of freedom created by the existence of multiple calculation methods and emission factor databases, which deliver markedly different emissions estimates for the same underlying activity data inputs. For instance, emission factors in the UK-Defra database are on average 10% lower than those in the US-EPA database, with substantially more variation. Preparers of GHG emissions calculations are required to exercise judgement in selecting the appropriate approach to employ. This framework, we argue, is ripe for being gamed and is unlikely to produce accurate estimates of companies’ true emissions in a durable way. We show, via a pilot study using proprietary data, that these differences are material. If gaming opportunities are fully exploited, actual emissions for some firms could be several times larger than those currently reported. We offer five policy recommendations aimed at making the calculation and reporting of GHG emissions robust.