Establishing a greenhouse gas (GHG) emissions baseline is a fundamental step in any corporate sustainability strategy. It serves as a reference point against which future reductions are measured, providing credibility to climate targets. However, as organisations refine their data collection processes, expand their operations, or update methodologies, their emissions inventory may change. This is where baseline restatement becomes critical.
What is baseline restatement?
Baseline restatement refers to the process of adjusting your original emissions baseline to ensure consistency and comparability over time. The GHG Protocol outlines specific circumstances under which a company should consider restating its baseline.
Why is baseline restatement important?
A well-managed emissions baseline ensures that companies track real progress rather than fluctuations caused by structural or methodological changes. Without restating the baseline, companies might:
- Overstate or understate emissions reductions
- Struggle to maintain comparability over time
- Provide misleading information to investors, regulators, and other stakeholders
It’s natural for data quality to improve over time—especially in the early years of emissions tracking. For example, calculations within the first year can often involve estimates and assumptions. However, as companies refine their processes, they gain access to more accurate and granular data. If these refinements significantly impact reported emissions, a structured approach to restatement will help to maintain transparency and credibility.
When should you restate your baseline?
The GHG Protocol Corporate Standard outlines key scenarios where companies should adjust their baseline emissions:
- Structural changes – mergers, acquisitions, or divestitures that significantly alter the organisation’s structure
- Methodology updates – changes in calculation methods, emission factors, or access to better data sources
- Scope expansion – the inclusion of additional facilities, operations, or emissions sources
- Significant data corrections – if errors in previously reported emissions are identified
Without restating the baseline in these cases, companies may either artificially inflate, or understate, their progress toward reduction targets.
When should you not restate your baseline?
Baseline restatement is not necessary with every data update. It should be avoided when changes in emissions are due to genuine operational improvements rather than structural adjustments. Examples include:
- Emissions reductions from efficiency measures – If a company cuts emissions by adopting renewable energy, optimising processes, or implementing efficiency measures, these improvements should be reflected as actual reductions rather than adjustments to the baseline.
- Short-term variability – year-on-year fluctuations caused by weather conditions, production cycles, or temporary operational changes typically do not warrant a restatement.
- Minor data refinements – small updates that do not materially impact the overall emissions inventory should be documented but do not require baseline adjustment.
How to approach baseline restatement
To maintain consistency and accountability, companies benefit from establishing a restatement policy from the outset. This ensures that when the time comes, decisions are made based on predefined criteria rather than ad hoc judgements. Consider to:
- Clearly define when and how restatements occur
- Align with requirements set by the framework on restatement
- Recalculate the baseline and the years in between, if applicable
- Ensure that changes are well-documented and communicated transparently in sustainability reports
By setting these rules early, companies can navigate future data improvements within clearly set parameters, ensuring a consistent approach that builds trust with stakeholders.
Ecomatters support
If you would like to discuss working with Ecomatters on the restatement or establishment of your emissions baseline you can plan a free consultation call with our experts.
