Understanding emission reporting restatements

Understanding emission reporting restatements: why companies are rewriting their climate narratives and why you should  

This blog explores the concept of greenhouse gas (GHG) emission baseline restatements, using two public case studies to illustrate why restatements are happening, how companies handle them, and what it means for stakeholders tracking climate progress. 

A maturing field of GHG reporting 

The Greenhouse Gas Protocol has become the leading international standard for GHG emissions reporting. As adoption increases, organisations are moving towards more consistent methodologies, better-defined boundaries, and improved data accuracy. 
In many ways, GHG reporting is beginning to resemble the world of financial reporting—a field that has had decades to evolve into a rigorously standardised discipline. Climate-related disclosure, by contrast, is still in its early stages but is maturing rapidly. Regulatory developments in both Europe and North America are accelerating this process. For example, the Corporate Sustainability Reporting Directive (CSRD) and the European Sustainability Reporting Standards (ESRS) are pushing companies in the EU towards more detailed and comparable sustainability disclosures. Meanwhile, in the US, the Securities and Exchange Commission (SEC) had proposed new climate disclosure rules that would have required public companies to report on climate-related risks and GHG emissions.

However, these rules have been paused following legal challenges and a change in administration. At the state level, California has adopted its own climate disclosure laws, which are moving forward and will affect many large companies doing business in the state. While these regulatory frameworks differ in scope and approach, they both reflect a broader shift: climate disclosure is moving from voluntary best practice to regulatory expectation. This transformation raises the bar for transparency and forces companies to revisit past practices. 
An increasing number of companies have begun publishing their GHG emissions. While industry frontrunners have been tracking and disclosing emissions for over a decade, broader corporate engagement in carbon accounting is a more recent phenomenon. This wave brings both opportunity and complexity, particularly as the field matures and standards evolve. 

As expectations around emissions reporting become more rigorous, many companies are not only improving the quality of new disclosures but also reassessing what they have reported in the past. Early inventories were often based on limited data, evolving methodologies, or different organisational boundaries. As standards solidify and data availability and quality improve, past reports may no longer reflect a company’s best understanding of its emissions and, more importantly, its actual and current situation. This has led to a growing number of restatements, recalculations or corrections of previously reported emissions data, particularly related to base year emissions. 

The foundation: what the GHG Protocol says about restatements 

The GHG Protocol Corporate Standard provides guidance on when and how companies should recalculate previously reported emissions to ensure accurate data over time and to prevent misrepresenting their progress toward GHG reduction targets. According to the GHG Protocol Corporate Standard (WRI & WBCSD, Revised Edition, 2004, Chapter 5, pp. 33–39) companies should recalculate historical emissions in the situations below: 

• Structural changes: mergers, acquisitions, or divestitures that alter organisational boundaries 
• Methodology improvements: changes in emission factors, calculation methods, or use of more accurate data 
• Scope expansion: adding new facilities, operations, or emissions categories 
• Significant errors: discovering misstatements or gaps in historical data 

The GHG Protocol requires companies to establish a base year recalculation policy. This policy must include a significance threshold, defined by each company and based on what would make the data no longer useful for decision making, which can be either qualitative or quantitative (e.g., a fixed percentage of total base year emissions). While the GHG Protocol does not prescribe a single definition of “material change” it requires that companies decide, document, and consistently apply this threshold to determine whether a recalculation is necessary. The policy also needs to include a recalculation method, which determines how historical data should be adjusted and which emissions sources are included in the revised baseline. 
Companies can choose between two main approaches: 

• Fixed base year: historical emissions are recalculated using a consistent reference year 
• Rolling base year: the baseline year moves forward over time, so the reference point is always recent 

Each approach has its trade-offs. A fixed base year provides consistency over time but can become outdated. A rolling base year offers greater flexibility in reflecting organisational changes but can make it harder to track progress consistently over the long-term. 
The GHG Protocol also outlines a few situations where recalculation is not required, even if changes occur: 

• No recalculation for facilities that did not exist in the base year 
• No recalculation for outsourcing/insourcing if emissions are reported under Scope 2 or 3 
• No recalculation for organic growth or decline in operations 

To better understand how restatements play out in practice, let’s look at two real-world examples. These cases illustrate the different reasons companies may choose, or be required, to recalculate their emissions, and how those changes are communicated to stakeholders. From methodological updates to changes in organisational boundaries, each case highlights the practical implications of restatements in a rapidly evolving reporting landscape. 

Case study 1: Ahold Delhaize – restating millions of tonnes 

In its 2024 annual report, Dutch retail group Ahold Delhaize restated emissions data across their scopes and categories. The company did this to reflect methodological improvements (such as switching from gross to net calorific value), incorporate better emission factors, automate data processing, and update boundaries after divesting some stores and including new categories like joint ventures and sold electrical appliances. These changes aimed to improve data accuracy and ensure alignment with evolving reporting standards. While the company provided detailed technical explanations, the changes drew public attention, particularly regarding the impact on the company’s climate targets and transparency.  
For Scope 1 and 2, Ahold Delhaize made several updates. The energy data methodology was revised, switching from gross to net calorific value, leading to reducing energy-related emissions. Additionally, emissions from divested own stores in Belgium were removed. For Scope 3 adjustments, we selected a few highlights: 

• Improved emission factors for purchased goods and services led to downward revisions of 2,300 ktCO₂e (2022). 
• Capital goods were moved from Category 1(Purchased goods and services) to Category 2 (Capital Goods). 
• Ahold Delhaize’s 2024 sustainability restatement includes adjustments in Scope 3 emissions reporting, notably between Category 1 (Purchased goods and services) and Category 3 (Fuel- and energy-related activities), but there is no explicit confirmation that upstream emissions from sold fuels were reallocated from Category 1 to Category 3. 
• Methodological changes: manual data entry was replaced with automated estimation tools across several categories. 
• New inclusions: emissions from sold electrical appliances (category 11) and proportional emissions from joint ventures (category 15). 

While the restatements were well-documented in the annual report, the public debate focused less on the technical changes and more on their consequences. An article by Financieel Dagblad noted that the company’s updated emissions baseline and target alignment gave the impression that significant reductions had been achieved, when in reality, some of the perceived progress resulted from methodological and boundary changes rather than actual performance gains. This raised questions around stakeholder trust, especially in light of growing scrutiny on how companies set and report on climate targets. 

Case Study 2: Maersk – a transparent recalculation policy 

A very different yet equally instructive case comes from shipping giant Maersk, which has taken a particularly proactive and transparent approach to managing restatements and recalculations. In early 2024, Maersk published a detailed Base Year Recalculation Policy. This policy sets out in clear terms when recalculations are required, how they should be performed, and how restatements differ from recalculations, something that often creates confusion among stakeholders. 
The policy describes: 

• Triggers for recalculation: including significant structural changes such as mergers, acquisitions, and divestitures that impact organisational boundaries, methodological updates like improved emission factors or more precise data, and the correction of significant historical errors. 
• Methodological approach: outlining how recalculations will be applied retrospectively to ensure consistency across the reporting timeline. 
• Distinction between recalculations and restatements: recalculations are systematic updates driven by improved methods or boundary changes, while restatements are corrections to previously published data where errors or misstatements have been identified. 

By publishing this policy publicly, Maersk has established clear guardrails that reassure stakeholders: restatements and recalculations are not arbitrary but guided by a formal, transparent process aligned with the GHG Protocol. 
In its 2024 annual report, Maersk illustrated how this works in practice. The company disclosed: 
“We made a correction to scope 1 emissions, as refrigerant emissions had been overstated in 2023. The correction led to a restatement of scope 1 emissions of 1.7 million tonnes CO₂e.” 
While the correction itself was concisely explained, the broader context, including how this restatement affected prior years, was detailed in earlier reports. This meant stakeholders who wanted to see the year-by-year adjustments had to look across multiple documents. This is a common challenge in climate reporting: even when restatements are disclosed transparently, the cumulative effect over time can remain opaque without consolidated tables or visual summaries. 
While Maersk’s policy is solid, its implementation could be enhanced and made clearer by presenting all changes visually within one document: 

• Publishing a dedicated recalculation policy to establish clear rules in advance. 
• Explaining clearly why the correction was necessary, overstated refrigerant emissions, and linking it back to their policy. 
• Documenting the impact across reporting periods, even if full details required consulting earlier disclosures. 
• Aligning these processes with international standards to show that restatements are driven by better data and accountability, not by shifting targets for reputational benefit. 

In the fast-evolving world of climate disclosure, this level of transparency signals maturity: the willingness to admit past overstatements, correct them, and explain the rationale openly to stakeholders. 

Final reflections: is restating emissions a problem? 

Restatements can sometimes be perceived as moving the goalposts—and in some cases, they can obscure genuine progress if not communicated properly. However, when done transparently and systematically, restatements are a sign of better data, improving methodologies, and a maturing approach to climate disclosure. Rather than undermining trust, restatements can reinforce it—provided companies handle them carefully. 
Best practice for communicating restatements and recalculations should include: 

• A published recalculation policy: outlining what triggers recalculations or restatements, how they are performed, and what significance threshold is applied. 
• Clear and accessible communication: describing changes in plain language, supported by data tables or graphics showing before-and-after figures so stakeholders can easily see the impact. 
• Consistency with frameworks: aligning with recognised standards like the GHG Protocol and referencing external initiatives like the Science Based Targets initiative (SBTi) to demonstrate credibility. 
• Transparency about impact on targets: explaining if, and how, recalculations affect climate goals or progress toward them. 
• Distinction between genuine improvements and structural changes: making sure stakeholders understand whether reductions stem from operational efficiencies, divestitures, or purely methodological updates. 

Done well, restatements should not be seen as hiding poor performance, but as part of a broader journey towards more accurate and credible emissions data. They reflect the fact that corporate carbon accounting is still evolving, and that better methods and better data inevitably lead to updates. 
At 2impact, we help organisations turn this complexity into clarity: drafting recalculation policies, improving emissions data quality, and designing transparent, stakeholder-focused communications. Because in the end, restatements are not just numbers; they are about trust, accountability, and demonstrating a real commitment to climate action that stakeholders can rely on. 

Linkt to Climate and Nature service page.