Greenhouse gas (GHG) data collection is at the centre of credible climate reporting. And for many teams, it is also one of the hardest parts to get right.
As expectations around greenhouse gases reporting increase—from customers, regulators and supply chains—you’re under growing pressure to produce GHG inventories that are accurate, consistent and defensible. On paper, the process looks straightforward. In practice, it rarely is.
Data is often found across multiple systems, teams and sites. Emissions sources are not always clear. Methods change over time. And errors made early in the process can follow you through reporting, target-setting and public claims.
Understanding GHG Data Collection and Reporting
Before looking at specific challenges, it helps to clarify what GHG data collection and reporting involve in practice.
What greenhouse gases reporting involves
Greenhouse gases reporting is the process of identifying emissions sources, collecting activity data, applying calculation methods and reporting results in a structured and transparent way. Most inventories cover carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O), with fluorinated gases included where relevant to your activities.
The result is usually a GHG inventory that shows emissions by source and scope, aligned to recognised frameworks such as the GHG protocol or ISO 14064.
How GHG data supports ISO 14064-1 compliance
ISO 14064-1 sets requirements for designing, developing and reporting organisational-level GHG inventories. It places strong emphasis on accuracy, completeness, consistency and transparency.
That means the quality of your data is important. Weak data collection leads to gaps, unclear assumptions and reporting that becomes difficult to support during internal review or external verification.
Where teams typically struggle
Most problems do not come from a lack of intent. They usually arise from:
- complex operational structures
- fragmented data ownership across teams
- limited historical records
- uncertainty around methods and boundaries
As your reporting matures or expectations increase, these issues tend to compound rather than resolve themselves.
Incomplete or Poor-Quality Activity Data
The most common source of error in GHG reporting is weak underlying data.
Missing data across operations and sites
If you operate across multiple locations, you may already be familiar with this problem. Energy, fuel or refrigerant data might be available for some sites but missing for others, often because systems and record-keeping differ.
In some cases, the data exists but is hard to access. In others, it was never recorded in a way that supports emissions reporting.
Inconsistent data formats and record-keeping
Even when data is available, it is often stored in different formats. One team may track fuel use monthly, another quarterly. Units vary. And supporting evidence may be incomplete or scattered across systems.
When you try to consolidate this information, inconsistencies increase the risk of transcription errors and make review more time-consuming than it needs to be.
Reliance on estimates instead of measured data
When measured data is not available, you may have no choice but to rely on estimates. This is sometimes unavoidable, especially in early reporting years.
However, heavy reliance on estimates reduces confidence in the final inventory and makes year-on-year change harder to interpret.
Defining Organisational and Operational Boundaries
Boundary setting is a technical requirement, but it is also one of the most practical challenges in GHG reporting.
Challenges with organisational boundaries
Organisational boundaries define which parts of your organisation are included in the GHG inventory. This may be based on equity share, financial control or operational control.
If your structure includes acquisitions, partial ownership or complex group arrangements, boundary decisions can quickly become difficult and open to interpretation.
Scope 1, Scope 2 and Scope 3 classification issues
Once boundaries are set, emissions must be classified into Scope 1, Scope 2 and Scope 3.
Common problems you may encounter include:
- misclassifying leased assets
- double counting between scopes
- inconsistent treatment of electricity and fuel use
These issues are often only discovered during internal review or verification, rather than at the data collection stage.
Shared assets, leased operations and joint ventures
Shared facilities and joint ventures raise questions about responsibility for emissions. Without clear agreements and documented assumptions, different parties may report the same emissions or leave them out altogether.
Complexity in Scope 3 Emissions Data
For many teams, Scope 3 emissions represent the largest share of the footprint—and the least certain.
Limited visibility across the value chain
Scope 3 data depends heavily on information from suppliers, contractors and customers, which in most cases you do not control or collect directly.
Supplier data availability and reliability
Even when suppliers provide emissions data, it may not be complete, current or calculated using consistent methods. You may receive figures with limited supporting evidence or without specificity on boundaries and assumptions.
Smaller suppliers often lack the resources or experience needed for accurate greenhouse gases reporting, which adds uncertainty to your overall inventory.
Double counting and overlap risks
Within complex value chains, the same activity can appear in multiple Scope 3 categories. Without careful mapping, some emissions could end up being counted more than once.
Agree on category boundaries early and keep them consistent, so Scope 3 totals don’t shift for avoidable reasons.
Applying the GHG Protocol Correctly
The GHG protocol is widely used, but applying it well requires judgement, not just compliance.
Common misunderstandings of the GHG accounting protocol
It is easy to treat the protocol as a checklist. When that happens, relevance and materiality are lost.
Misunderstandings often arise around:
- which Scope 3 categories are required versus optional
- when different calculation methods are appropriate
- how exclusions should be justified and documented
If these points are not clear, your reporting will quickly become inconsistent.
Choosing the right calculation approaches
The protocol allows different approaches depending on the quality and availability of data. The challenge is choosing the methods that suit your current data without undermining transparency.
An approach that works one year but changes the next can make trends difficult to explain. Choose methods that match the quality of your available data, and be explicit about the limits of what the method can show.
Aligning the GHG protocol with ISO 14064 requirements
The GHG protocol and ISO 14064 are compatible, but they are not identical. If you mix terminology or requirements without clarifying, reporting can become confusing for reviewers and verifiers.
ISO 14064-1 helps bring structure by setting clear principles for boundaries, data quality and documentation, which supports more consistent use of the protocol.
Difficulties with Emissions Factors and Calculations
Even with solid activity data, errors often appear during calculation.
Selecting appropriate emissions factors
Emissions factors vary by geography because energy is produced differently in different places. Electricity in one country may come largely from renewables, while another relies more on fossil fuels, which changes the emissions associated with each unit of energy used.
Factors also differ by fuel type and by year. Diesel, petrol and natural gas are not identical across markets, and published factors are updated over time as grids change and methods improve. Using factors that do not match the location, fuel or reporting period of your activity data can distort results and make comparisons harder to explain.
Recording the source and version used makes later review much easier.
Keeping factors up to date
As grids decarbonise and methodologies improve, emissions factors change. If you rely on outdated factors, year-on-year comparisons become misleading.
It is not uncommon for teams to struggle to track which factors were used in previous reporting periods, especially when calculations have been updated or staff change.
Data Management, Systems and Internal Controls
As your GHG inventory grows, the way data is managed becomes just as important as the data itself.
Manual data collection and spreadsheet risks
You may still be relying on spreadsheets to collect and consolidate emissions data. That can work quite well in early stages, but it quickly becomes harder to control as volumes increase. Broken formulas, overwritten cells and unclear file ownership are common risks.
Version control and audit trails
A credible GHG inventory needs a clear audit trail. You should be able to show where data came from, how calculations were performed and when changes were made.
Without proper version control, it becomes difficult to explain differences between reporting periods or respond confidently to internal questions and external review.
Internal roles, responsibilities and accountability
GHG reporting usually relies on inputs from several teams. Without named owners and review steps, gaps and late changes become routine. Clear ownership helps ensure data is collected on time, checked properly and approved before it feeds into reporting.
Keeping Reporting Consistent Over Time
Consistency is a core principle of both the GHG protocol and ISO 14064-1 but maintaining it takes active management.
Changes in operations and business structure
Mergers, acquisitions, site closures and process changes all affect your emissions profile. When changes like this occur and are not handled carefully, year-on-year comparisons can become misleading. You need clear rules for when and how your inventory is updated to reflect structural change.
Methodology changes and restatements
As data quality improves, you may need to update calculation methods. That is a positive step, but changing methods without restating prior-year data can create artificial increases or decreases. It is essential to document changes and explain their impact if you want your reporting to remain credible.
Maintaining year-on-year comparability
Stakeholders expect to see progress over time. But inconsistent boundaries, data sources or calculation approaches make that harder to demonstrate and easier to challenge.
Audit Readiness and Verification Challenges
Verification tends to expose gaps that felt minor during data collection—especially where evidence, boundaries or calculation choices were never pinned down.
Gaps between reported data and supporting evidence
Reported figures must be backed by evidence. Missing invoices, estimates or undocumented assumptions are common findings during review. These gaps can delay verification and lead to last-minute corrections under time pressure.
Common issues identified during verification
Verifiers frequently identify issues such as:
- unclear boundary definitions
- inconsistent treatment of similar emissions sources
- calculation errors carried forward from earlier years
- limited explanation of exclusions
By addressing these points early, you can reduce disruption and shorten the verification process.
Preparing data for independent assurance
Audit-ready GHG data is well organised, clearly documented and internally reviewed. That level of readiness does not happen by chance. It comes from planning how data is collected, checked and approved throughout the reporting cycle, not from rushing to assemble evidence at year end.
How ISO 14064-1 Helps Address These Challenges
ISO 14064-1 provides a structured framework for improving how you manage GHG data.
Structured requirements for greenhouse gas inventories
The ISO standard sets clear expectations for boundary setting, data collection, calculation methods and reporting content. In doing this, it reduces ambiguity and supports consistent decision-making.
Improving transparency and consistency
ISO 14064-1 places strong emphasis on documented assumptions, data quality management and traceability. These requirements directly address many of the issues that appear during reporting and verification.
Producing credible greenhouse gases reporting
By following a recognised international standard, you can demonstrate that your GHG reporting is based on clear principles and reliable processes. This makes boundary choices and calculation methods easier to review, and easier to keep consistent from one reporting cycle to the next.
Practical Steps to Improve GHG Data Collection and Reporting
Improvement does not require perfection. It requires structure, ownership and steady progress.
Strengthening data governance and controls
Clear procedures for data collection, review and approval reduce errors and improve confidence in reported figures.
Improving data quality across your organisation
Prioritising measured data, improving record-keeping and working with suppliers all contribute to stronger results over time.
Training teams on ISO 14064 and GHG reporting expectations
Training helps your teams understand not just what data is needed, but why it matters and how it will be used.
When External Input Is Useful
Some challenges are best addressed with independent input.
Using gap analysis to identify weaknesses
A structured gap analysis can show where your current practices fall short of ISO 14064-1 requirements and where improvements will have the greatest impact.
The role of ISO certification and training
Certification and training help show that your systems meet recognised standards and are applied consistently.
How ISOQAR supports GHG management and reporting
ISOQAR supports you through ISO 14064-1 certification, training and related services, helping turn complex reporting requirements into clear, workable processes.
Building Confidence in GHG Reporting
Reliable GHG data does not happen by accident. It comes from obvious boundaries, good data, consistent methods and strong internal controls.
By understanding the common challenges in GHG data collection and reporting—and addressing them through recognised standards such as ISO 14064-1—you can produce greenhouse gases reporting that stands up to scrutiny and supports long-term sustainability goals.
Talk to our experts about ISO 14064-1 certification, training or gap analysis, and get practical support for your GHG reporting needs.
