On 29 July 2026, the Greenhouse Gas Protocol confirmed that it will combine its corporate carbon accounting standards with ISO 14064-1 into a single, harmonized corporate standard. The change brings together the GHG Protocol Corporate Standard, Scope 2 Guidance, Scope 3 Standard and the developing Actions and Market Instruments framework with ISO's organizational greenhouse gas accounting standard.

For companies, this changes the structure and timetable of a core corporate emissions accounting framework and could affect how organizations measure emissions, use environmental attributes, structure renewable energy procurement and report progress toward climate targets.

The important point today is that the new standard is not yet final. Existing GHG Protocol and ISO standards remain in effect. A consolidated draft is expected to go to public consultation in the second quarter of 2027, with publication of the revised corporate standard currently estimated for the fourth quarter of 2028. Transition arrangements will be communicated as the new standards are published.

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Why GHG Protocol and ISO are combining their standards

GHG Protocol and ISO have historically developed separate greenhouse gas accounting frameworks. Both are widely used, but they have different structures, terminology and approaches to implementation and verification. The organizations first announced a strategic partnership in September 2025 to harmonize their portfolios and reduce fragmentation. The July 2026 update goes further by confirming that the corporate standards will be consolidated into one co-branded global standard.

The planned standard will combine corporate accounting requirements covering Scope 1, Scope 2 and Scope 3 emissions, as well as the developing treatment of actions and market instruments, with ISO 14064-1. GHG Protocol says the new standard is expected to use a two-part structure supported by additional implementation guidance.

Corporate carbon data now sits inside a much wider reporting system than it did when the original GHG Protocol Corporate Standard was published in 2004. Emissions inventories are used in target setting, investor reporting, regulated disclosure, procurement decisions and assurance. Companies may need to reconcile GHG Protocol requirements with ISO standards, regulation and voluntary programs. Harmonization is intended to reduce some of that duplication. ISO 14064-1 itself establishes organization-level requirements for the quantification and reporting of greenhouse gas emissions and removals, including inventory management and reporting requirements.

It should not, however, be interpreted as immediate convergence across every disclosure or target-setting framework. Regulators, disclosure programs and target-setting bodies will continue to decide which elements of the new framework they recognize for their own purposes.

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Scope 2 is now less settled than it appeared in 2025

One of the most important consequences of the ISO alignment concerns Scope 2.

In 2025, GHG Protocol consulted on proposed revisions to the Scope 2 Guidance. Those proposals included significant changes to both the location-based and market-based methods. Among the most commercially important proposals were hourly matching for market-based electricity claims, deliverability requirements, revised emission factor rules and greater use of granular electricity data.

For energy buyers, these proposals raised a clear possibility that annual renewable energy certificate procurement would eventually become insufficient for some corporate accounting purposes. A company buying enough annual RECs to match its annual electricity consumption might instead need to demonstrate that renewable generation occurred at the same time, and potentially within an eligible geographic boundary, as the electricity it consumed. The consultation proposals also included possible measures to ease implementation, including load profiles, exemptions for smaller organizations, legacy treatment for existing contracts and phased implementation.

That direction has not been abandoned, but it is no longer correct to present hourly matching or deliverability as settled future GHG Protocol requirements.

The Scope 2 consultation received nearly 1,100 responses from 56 countries. GHG Protocol reported broad interest in improving accuracy, consistency and credibility, but significant disagreement over how electricity procurement should be reflected in corporate inventories. Respondents also raised concerns about implementation burden, regional data availability, assurance and access for smaller companies.

As a result, GHG Protocol is now exploring multiple reporting approaches that reflect different theories of change. During the third and fourth quarters of 2026, the Scope 2 Technical Working Group is expected to review both public consultation feedback and input from ISO. Revised Scope 2 content will then be included in the consolidated 2027 draft. The Independent Standards Board will determine whether any Scope 2 issues require another round of consultation.

For corporate buyers, the practical conclusion is simple. Do not assume that the 2025 Scope 2 consultation draft is the final rulebook.

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Environmental attributes are moving into a broader accounting framework

The developing Actions and Market Instruments, or AMI, workstream may be just as important for environmental commodity markets.

GHG Protocol defines market instruments broadly as contractual arrangements that enable the creation, transfer or claiming of greenhouse gas-related environmental attributes. This creates a direct connection to markets for renewable electricity certificates, renewable fuels, commodity certificates and other environmental attributes.

The current proposal is a multi-statement reporting structure. Instead of forcing every climate action into one corporate inventory number, companies could report different forms of information separately. GHG Protocol has described three components: physical inventory emissions, market-based or contractual inventory emissions, and the emissions impact of corporate actions and investments calculated using consequential methods.

This distinction could become important for markets that have developed credible chain-of-custody and certificate systems but do not currently fit cleanly within Scope 1 or Scope 3 inventory accounting.

GHG Protocol's current development plan is explicit that market-based approaches similar to the Scope 2 market-based method are not currently included or permitted for calculating Scope 1 or Scope 3 emissions under the Corporate Standard or Scope 3 Standard. The AMI workstream is examining how market instruments and climate actions could be reported more systematically without simply netting them against physical emissions.

That could create a more structured accounting pathway for instruments associated with products such as renewable natural gas, sustainable aviation fuel and lower-carbon commodities. It does not mean these instruments have automatically been approved for Scope 1 or Scope 3 reductions. Eligibility criteria, quality requirements and detailed accounting rules are still being developed, with the AMI draft scheduled to form part of the 2027 consultation.

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What this means for corporate procurement

The direction is toward more differentiated carbon accounting.

Companies may need to understand not only how much renewable or lower-carbon energy they procure, but where it was produced, when it was produced, what attribute was transferred, how ownership was recorded, whether the instrument is recognized by the relevant accounting framework and what claim the transaction supports.

For renewable electricity, this increases the importance of certificate quality, registry data, geographic eligibility, temporal data and contract design. Even if hourly matching is modified before the final standard is published, the consultation has made clear that greater temporal and geographic precision, deliverability and the relationship between procurement and reported emissions remain central issues in the Scope 2 revision.

For other environmental commodities, the AMI process could create clearer distinctions between changes to a physical emissions inventory and the separately reported climate impact of a procurement action. That distinction may help companies use credible market instruments without presenting them as direct inventory reductions when the accounting rules do not support that treatment.

This also changes the role of environmental commodity procurement teams. Buying the lowest-cost eligible certificate may no longer be enough. Procurement increasingly needs to be coordinated with carbon accounting, sustainability reporting, legal review, assurance and target-setting requirements.

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What companies should do before 2028

Companies do not need to rebuild their emissions inventories today. The existing GHG Protocol and ISO standards remain operative until replacement standards are published and transition arrangements are defined.

They should, however, avoid treating the current period as business as usual.

Organizations with large electricity loads should assess whether their data systems can support more granular consumption and procurement information. Buyers using RECs or other energy attribute certificates should review the geographic and temporal information available from registries and suppliers. Long-term renewable energy contracts should be examined for flexibility if future accounting requirements become more granular.

Companies using environmental attributes outside electricity should be especially careful with claims. A functioning certificate registry or book-and-claim system does not by itself establish that a transaction can reduce Scope 1 or Scope 3 emissions under GHG Protocol. Until the new rules are final, companies should distinguish between physical inventory emissions, contractual environmental attributes and separately quantified emissions impacts.

The 2027 consultation will be a critical point. Companies, traders, utilities, registries and large energy users will have an opportunity to assess the consolidated framework rather than separate pieces of Scope 2, Scope 3 and market-instrument guidance. The current timetable places the consolidated public consultation in Q2 2027 and final publication in Q4 2028, although GHG Protocol notes that the timetable remains subject to change.

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The commercial impact

The GHG Protocol and ISO consolidation points toward a carbon accounting market that requires more traceability, clearer ownership of attributes and stronger links between procurement data and reported emissions. This is also consistent with the proposed move toward separating physical emissions, contractual or market-based emissions and the broader emissions impact of corporate actions.

For environmental commodity markets, this can create demand for better specified products, stronger registry infrastructure, more detailed transaction data and procurement strategies designed around the buyer's accounting objective.

The risk is acting too early on draft requirements or too late on the underlying market direction. Companies that assume every 2025 proposal will become mandatory could over-engineer procurement. Companies that assume annual, geographically broad certificate purchasing will remain sufficient indefinitely may find themselves with contracts and data systems that are difficult to adapt.

If your organization is reviewing renewable electricity procurement, environmental attributes or the potential impact of the GHG Protocol and ISO changes on future purchasing strategies, contact AFS Commodities to discuss your requirements and how your procurement approach can remain aligned with a changing carbon accounting framework.