Greenhouse gas (GHG) verification – the independent review of your emissions data – is becoming an expected step in sustainability reporting. Sustainability information is becoming more vital to stakeholder decision-making. Voluntary frameworks and regulators alike are increasingly emphasizing the importance of verified disclosures. For example, CDP encourages companies to verify their emissions (offering scoring boosts for third-party assured data) and upcoming regulations require verification such as California’s SB 253 and SB 261, Europe’s Corporate Sustainability Reporting Directive (CSRD), and more. The trend is clear: whether for investors, customers, or compliance, your sustainability data needs to be accurate, reliable, and easy to verify.
As assurance, specifically GHG Verification, becomes more common, many preparers wonder how to ensure a successful audit and confidence in their disclosures. Here are some steps that companies can take in the short, medium, and long term to ensure satisfied stakeholders (and verifiers).
First, a note: A recurring theme from industry leaders is that sustainability information should be as trustworthy as financial statements. Based on current trends, it would not be surprising if carbon data will soon appear alongside financial results if they are not already. As a result, this data must be prepared with the same level of precision and quality control. As a GHG inventory preparer, you should gear your process to satisfy a reasonable assurance audit even if you’re only undergoing limited assurance now. Building early robust practices will prepare you as stakeholders demand deeper scrutiny of emissions data.
Short-Term: Strong internal controls and checks
Implementing internal quality controls on your data is one of the most important steps to improve verifiability. In practice, this involves establishing procedures to ensure accuracy, completeness, and consistency at every stage of inventory preparation. The Greenhouse Gas Protocol outlines some examples of simple controls to have in place quickly, including:
- Require a second person to review or recalculate key emission calculations as a cross-check
- Compare this year’s data to last year’s and investigate any anomalies (significant changes, out-of-range values)
- Ensure activity data (fuel use, electricity consumption, etc.) ties back to solid evidence – utility bills, meter readings, invoices, production logs – and maintain copies of all such source documents. A verifier will ask to see that underlying evidence; if there is no supporting documentation for a disclosure, it cannot be verified.
- Integrate GHG reporting with core operational and assurance processes rather than treating it as an isolated task
To streamline the process, leverage your organization’s expertise in financial controls—for example, involve internal audit or IT teams to help set up data controls.
Medium Term: Inventory Management Plans
Once the core components of a process are in place, the next step is to formalize them as part of an Inventory Management Plan (IMP). An IMP is a living manual for your inventory process. Per the EPA, it “describes an organization’s process for completing a high-quality, corporate-wide GHG inventory.”
In practical terms, an IMP documents all the key aspects of your GHG accounting program, including:
- Organizational and operational boundaries (which facilities, sources, and emissions are included),
- The methodologies and emission factors used for each source,
- The data collection process and storage
- The roles and responsibilities of team members, and
- The quality assurance/quality control procedures are in place.
By formalizing the process in an IMP, preparers ensure consistency year after year. The key is that an IMP is not a static document; it should evolve with your company. Investing time in a thorough IMP makes annual reporting more routine and verification-ready. Importantly, companies with well-thought-out IMP often find that third-party auditors have an easier job and ask fewer remedial questions because all the information on processes and methods is readily available and organized.
Long-Term: Continuous improvement
In the long run, the goal is to bake quality and verification-readiness into the DNA of your carbon management. Treat each verification cycle not just as a test to pass but as an opportunity to learn and improve. Verification findings often come with recommendations for better data or controls; the GHG Protocol suggests viewing the process “as a valuable input to the process of continual improvement.”
For instance, if your verifier notes a weakness – say, inconsistent record-keeping at one facility – use that insight to strengthen your system before the next cycle. Over years, these incremental upgrades lead to a very robust inventory process. In the long term, companies should aim to integrate GHG data management into their broader governance frameworks. Sustainability data should not live in a silo. Many leading companies are now aligning their carbon data management with financial reporting systems – some even map it to internal control frameworks like SOX. The rationale is that carbon emissions involve financial implications (energy cost, carbon pricing, etc.), so managing this data with the same rigor is just good business practice.
Similarly, long-term planning includes keeping an eye on evolving standards. New protocols, updated GHG calculation guidance, or new regulatory criteria may emerge (for example, the GHG Protocol’s Standards are being updated at this time). Ensuring your team stays educated – perhaps through training or participation in industry groups – will help future-proof your inventory.
Lastly, consider broadening the scope of what you verify over time. Many organizations start with getting limited assurance on their Scope 1 and 2 emissions. They may extend verification to Scope 3 emissions as they mature or move to reasonable assurance for a comprehensive data audit. This phased approach is sensible: it allows you to build confidence and systems gradually. However, the end-state vision is clear: a fully transparent, credible GHG inventory process that stakeholders can trust, year after year, as much as they trust the financial books. Achieving that level of reliability is a journey that starts with the concrete steps outlined above.
In conclusion, passing a GHG verification (whether a limited review or a rigorous reasonable assurance engagement) comes down to preparation and good data practices. By implementing internal controls, documenting your methods in an inventory management plan, and using reputable data sources, you make an auditor’s job straightforward and greatly increase the credibility of your climate reporting. As verification requirements ramp up across voluntary programs and mandatory regulations, organizations that proactively strengthen their GHG inventories will find the process far less daunting. Beyond just “passing” verification, you’ll provide the kind of trusted information investors and other stakeholders are increasingly looking for. If you need Greenhouse gas (GHG) verification, we can help.
