What is the equity share approach?

Quick Answer: The equity share approach is a method of defining an organisation's carbon accounting boundary based on its ownership stake in operations, joint ventures, or subsidiaries. Under this approach, a company reports a proportion of greenhouse gas emissions from each operation equal to its equity share (ownership percentage) in that operation, regardless of whether it has operational control. It is one of three consolidation approaches defined by the GHG Protocol Corporate Standard, alongside the operational control and financial control approaches.

What is the Equity Share Approach?

The equity share approach is a GHG accounting consolidation method that ties emissions reporting to ownership. If your company holds a 40% equity share in a joint venture, you report 40% of that joint venture's emissions in your carbon footprint, regardless of who manages the day-to-day operations.

This proportional logic reflects the idea that financial stake and emissions responsibility are linked. The more of a business you own, the more of its emissions you are accountable for.

The GHG Protocol Corporate Accounting and Reporting Standard, which is the most widely used framework for corporate carbon accounting, sets out the equity share approach as one of three methods organisations can use to define which emissions fall within their reporting boundary.

How Does the Equity Share Approach Work in Practice?

Applying the equity share approach requires two pieces of information for each operation: the total emissions from that operation, and your company's percentage ownership stake.

The calculation is straightforward:

• Identify all operations in which your company holds an equity interest (wholly owned subsidiaries, joint ventures, minority stakes)
• Obtain or estimate the total gross emissions from each operation
• Multiply total emissions by your equity share percentage
• Sum the results across all operations to arrive at your consolidated footprint

For example, if a company owns 60% of a manufacturing facility that emits 10,000 tCO2e per year, it reports 6,000 tCO2e from that facility. A co-owner holding the remaining 40% would report 4,000 tCO2e, assuming they also use the equity share approach. In theory, 100% of the facility's emissions are accounted for across the ownership group.

One practical complexity is data access. If you hold a minority stake in a joint venture, obtaining accurate emissions data from the operating partner is not always straightforward. This is a known limitation of the approach, and building data-sharing requirements into investment agreements where possible is advisable.

Equity Share vs Operational Control vs Financial Control

The equity share approach is one of three consolidation approaches defined by the GHG Protocol. Understanding the differences matters because the approach you choose affects which emissions you report and in what quantity.

Operational control: A company reports 100% of emissions from operations over which it has operational control, and 0% from operations it does not control, regardless of ownership stake. This is the most common approach for companies with straightforward corporate structures.

Financial control: A company reports 100% of emissions from operations over which it has financial control (typically where it has the ability to direct the financial and operating policies to gain economic benefit). Again, this is a 0% or 100% approach, not proportional.

Equity share: A company reports emissions in proportion to its ownership stake. This is the only proportional approach of the three, and it is the method most aligned with how financial results are consolidated in company accounts under equity accounting.

The right choice depends on your corporate structure, the nature of your investments, and what your stakeholders or reporting frameworks require. Companies with significant joint venture activity often find the equity share approach produces a more representative picture of their financial exposure to carbon risk. Companies with simpler structures typically default to operational control.

Once an approach is selected, it should be applied consistently across the entire reporting boundary and maintained year-on-year to allow meaningful comparison over time.

Why Does the Consolidation Approach Matter for Your Carbon Footprint?

The consolidation approach you choose can produce materially different emissions totals from the same underlying business activities. This is not a technicality. It affects the credibility of your footprint, your ability to set Science Based Targets (SBTi-aligned targets require a consistent and well-documented boundary), and the comparability of your data with peers.

For companies responding to frameworks such as SECR, CDP, or B Corp, or producing outputs for procurement questionnaires like PPN 006 or EcoVadis, a clearly documented consolidation approach is part of demonstrating methodological rigour. Stakeholders and auditors will ask which approach was used and why.

Choosing the equity share approach without the data infrastructure to support it can also create reporting gaps. If you cannot obtain emissions data from a joint venture partner, you may need to estimate, which introduces uncertainty into your footprint. Documenting those assumptions clearly, with the data sources and estimation methods used, is essential for a defensible inventory.

When Should a Company Use the Equity Share Approach?

The equity share approach is most appropriate when a company's financial reporting already uses equity accounting for investments and joint ventures, making it logical to align carbon accounting with the same ownership logic.

It is also the preferred approach in certain sectors, such as oil and gas and mining, where joint ventures are common and the GHG Protocol's sector-specific guidance recommends it. For companies in these sectors, the equity share approach is often the industry norm.

For most small and mid-sized companies with straightforward corporate structures (wholly owned subsidiaries or no significant joint ventures), the operational control approach is simpler to apply and equally valid. The equity share approach adds value where partial ownership is a meaningful feature of the business model.

If you are unsure which approach is right for your organisation, the decision should be made before you begin data collection, not after. Changing consolidation approach mid-reporting cycle requires restating prior-year figures, which creates additional work and can complicate year-on-year comparisons.

Seedling's carbon experts work through boundary-setting decisions like this with clients at the start of the process, so the right approach is documented and applied consistently from the outset, rather than revisited when it is harder to correct.

The consolidation approach is foundational to everything that follows in a carbon inventory. Getting it right at the start is one of the most important decisions in building a footprint that holds up to scrutiny.