Greenhouse Gas Protocol Changes – An Overview
This article is the first in a series of three that we will publish over Summer 2026, exploring the proposed changes to the Greenhouse Gas (GHG) Protocol’s Corporate and Scope 3 Standards and what they could mean for businesses.
The GHG Protocol provides the foundation for how organisations measure and report greenhouse gas emissions. While its use is not mandatory in itself, its methodologies underpin many of the world’s leading reporting and target-setting frameworks, including CSRD, ISSB, CDP and the Science Based Targets initiative (SBTi). As a result, it has become the de facto standard for organisations seeking to build credible emissions inventories, climate targets and net zero strategies.
Significant revisions to the Protocol are now underway for the first time in many years. As the GHG Protocol evolves, the frameworks and initiatives that rely on it are also likely to adapt. This means the proposed revisions are relevant not only to emissions accounting specialists, but also to organisations reporting under CSRD, disclosing through CDP, or setting science-based targets.
An ISO-GHG Protocol partnership announced in September 2025 aims to deliver unified, harmonised standards, creating a common global language for emissions accounting. Under the agreement, ISO and the GHG Protocol will combine their leading GHG standards into harmonised co-branded international standards.
As part of this process, major revisions to the GHG Protocol Standards are being developed to better align with the goals of the Paris Agreement, support harmonisation with other standards, and improve data quality, comparability and auditability.
Why should businesses pay attention now?
While the final standards remain under development and are not expected until 2027, businesses may benefit from assessing how the proposed changes could affect their emissions reporting, climate targets and transition plans.
The direction of travel is clear: expectations around the quality, consistency and transparency of emissions data continue to increase. Organisations that begin preparing now are likely to be better positioned as requirements evolve and stakeholder expectations continue to grow.
Throughout Summer 2026, we will publish a series of articles exploring the proposed revisions to the GHG Protocol, their potential implications for business, and practical considerations that organisations may wish to begin thinking about as they prepare for future implementation.
Who will the changes affect?
Companies with SBTi targets
These changes are particularly relevant to the BITCI membership given the large number of members that have set, or are planning to set, science-based targets through the SBTi.
Companies with SBTi-validated targets face the clearest and most direct exposure to the changes because the SBTi explicitly mandates GHG Protocol methodology. The new SBTi Corporate Net-Zero Standard (CNZS v2), expected to take effect between 2026 and 2028, is being developed with reference to the revised GHG Protocol.
Every company with a validated SBTi target is expected to adopt the updated methodology as part of its mandatory five-year target review process.
Companies in scope for CSRD and/or with operations in ISSB-aligned jurisdictions
Companies reporting under CSRD and those operating in ISSB-aligned jurisdictions are also likely to be affected, although potentially over a longer timeframe.
These frameworks reference GHG Protocol-aligned methodologies and are likely to incorporate the revisions once they are finalised. However, adoption is unlikely to be automatic or immediate.
In practice, mandatory reporters may be looking at the period between 2029 and 2030 before revised methodologies become formally embedded within regulatory requirements. Investor expectations and best practice reporting, however, are likely to move more quickly than regulation. We therefore encourage organisations to monitor developments closely and consider how the proposed changes could affect future reporting obligations.
CDP reporters
CDP reporters also face a probable, although less predictable, pathway to adoption.
CDP closely follows GHG Protocol methodology and typically incorporates changes through its own annual revision cycle, often with a lag of one to two years. Other frameworks and ratings systems, including GRI, EcoVadis and B Corp, operate in a similar way, referencing GHG Protocol methodologies while maintaining their own independent update cycles.
Accelerate Pact signatories
For signatories of Accelerate: The Business Pact for Climate and Nature, the Climate Transition Plan Scorecard will incorporate changes to the GHG Protocol once they have been finalised and agreed.
It is important to note that the final revised standards are not expected until 2027. However, organisations that begin understanding the proposed direction of travel now are likely to be better prepared for future changes to climate transition planning, emissions reporting and target-setting requirements.
For more info, please contact environment@bitc.ie
