Spreadsheets have long been the go-to tool for carbon accounting consultants, offering flexibility and low costs. But as the complexity of emissions data grows, they’ve become a liability. For companies relying on consultants who still use spreadsheets, the risks can be significant. Here’s what you need to know.

Human eError is everywhere

Mistakes are inevitable when humans manually input data into spreadsheets. Even small errors, like misplacing a decimal or mismatching units, can derail the accuracy of an entire emissions inventory. These errors are especially dangerous for compliance. Regulatory audits and sustainability reporting frameworks demand precision. If your inventory fails due to a simple input oversight, it can harm your reputation and delay progress on your sustainability goals.

The complexity of emissions data — such as converting fuel consumption to emissions or calculating multi-scope inventories — increases the chances of something slipping through the cracks. Relying on spreadsheets makes it nearly impossible to guarantee the level of precision required by frameworks like the GHG Protocol.

Inconsistencies creep in without warning

When multiple people work on a shared spreadsheet, inconsistencies become almost unavoidable. Everyone brings their own approach to naming conventions, formatting, and formulas. Over time, these differences compound, creating a patchwork system that’s difficult to audit.

For example, one consultant might label a category as "Air Travel - Domestic," while another uses "Domestic Flights." Even slight variations like this can disrupt calculations, especially when mapping emissions factors to activity data. Without standardization, ensuring consistency across projects becomes an uphill battle.

Formulas and macros are fragile

Spreadsheets rely heavily on formulas and macros to automate calculations, but these tools are far from foolproof. A single change in the structure of a sheet — like adding a column or renaming a tab — can break links and throw off entire workflows. Worse, identifying the source of these problems often takes hours of troubleshooting.

Imagine a macro designed to calculate Scope 3 emissions based on spend data. If an input cell is accidentally deleted or renamed, the entire calculation fails. These vulnerabilities are a nightmare when working under tight deadlines, especially with stakeholders expecting a polished and error-free output.

Audit trails are practically nonexistent

Spreadsheets lack robust tracking features, making it difficult to document how data was processed or by whom. During an audit, the absence of an audit trail can lead to rejected reports, further scrutiny, and even reputational damage.

For example, regulators or clients might ask for a detailed explanation of how specific emissions were calculated. Without a clear audit trail, consultants are left scrambling to piece together a narrative. This lack of transparency is one of the main reasons spreadsheets fail under third-party review.

They don’t scale with your business

Spreadsheets might work for small projects, but they quickly become unmanageable as data grows. Larger organizations often need to account for emissions across multiple facilities, geographies, and supply chains. Spreadsheets simply aren’t designed to handle the sheer volume of data or the complexity of calculations required for enterprise-scale carbon inventories.

This limitation is particularly evident in Scope 3 calculations, where emissions are spread across an extensive network of suppliers. Managing this level of complexity requires tools that can automate data processing and provide real-time insights — capabilities far beyond what spreadsheets offer.

Security is an afterthought

When sensitive data is stored in spreadsheets, security risks multiply. Files are often shared via email or stored on unsecured drives, leaving them vulnerable to breaches. For companies with proprietary supplier relationships or sensitive emissions data, this lack of protection is a serious concern.

If a spreadsheet containing confidential data is leaked, it doesn’t just expose the company to reputational harm. It could also lead to legal repercussions, especially in regions with stringent data protection regulations.

Compliance demands are outpacing spreadsheet capabilities

As regulatory frameworks like the CSRD (Corporate Sustainability Reporting Directive) evolve, the expectations for emissions data are becoming stricter. Companies are now required to provide detailed, transparent, and accurate emissions inventories. Meeting these demands with spreadsheets is a losing battle.

For example, the CSRD requires granular reporting on Scope 3 emissions, including supplier-specific data. This level of detail often involves complex calculations that spreadsheets struggle to manage. Falling short of these requirements can result in non-compliance penalties and a loss of trust among stakeholders.

Summary

• Human Error: Manual input errors in spreadsheets can undermine the accuracy of your emissions inventory, leading to failed audits and regulatory penalties.
• Inconsistencies: Lack of standardization among contributors makes maintaining data integrity challenging.
• Fragile Tools: Spreadsheets rely on formulas and macros prone to breaking, which can disrupt entire workflows.
• No Audit Trails: Spreadsheets fail to document data processing, making audits more difficult and less credible.
• Scaling Issues: They can’t handle the volume or complexity of data required for enterprise-level carbon accounting.
• Security Risks: Spreadsheets lack adequate protections for sensitive data, exposing companies to breaches and compliance failures.
• Compliance Challenges: New regulations demand levels of precision and transparency that spreadsheets simply cannot deliver.

These risks make spreadsheets an unsuitable tool for today’s carbon accounting needs. Moving to specialized software like Avarni ensures accuracy, scalability, and compliance. If you’re a consultant working on carbon accounting for clients today, get in touch with us to talk about how we can help you transition away from spreadsheet processes, like we have helped Schneider Electric and KPMG.