The role of consultants and software in corporate carbon reporting

 

None of this is technically extremely difficult. The carbon calculations themselves are well established. What makes it a real piece of work is coordinating all those stakeholders while keeping the reporting compliant as frameworks shift. In practice, three actors carry that load: internal sustainability teams, external sustainability consultants, and carbon accounting software.

 

This article looks at how those three roles divide up across companies of different sizes.

 

Reporting companies need to own their carbon numbers

 

Every company needs to own its carbon footprint. The sustainability manager and their leadership team carry the final responsibility for reducing the company's climate impact over time. It's the company that sets its climate targets, answers to its board and investors, and lives with the reputational and financial consequences if the numbers turn out to be wrong. Regardless of size, this is the bare minimum.

 

To own a solid carbon strategy, a detailed corporate carbon footprint is instrumental. The basic rules are well described in the Greenhouse Gas Protocol. In practice, though, applying them raises several complexities. First, a company needs to assess its boundaries to cover all significant emission sources. For instance, are land-based emissions relevant for a service company buying catering for its office canteen? (quick answer: most likely not.) Second, no company has perfect data. Gaps often need to be filled with expert estimations or extrapolations. Take for instance employee commuting. If there's no system that tracks this accurately per employee, someone has to make an estimate rather than leave a gap. Third, very few people have an intuition for whether 100 tCO2e is a lot or not, so making sense of the results requires reference points. All of this applies even more when addressing Scope 3 emissions.

 

None of these problems are unsolvable. They just require a specific kind of expertise, applied consistently. Large corporates, well above €1 billion in annual turnover, often have the scale to build this expertise in-house. Mid-sized companies, roughly between €10 million and €1 billion in turnover, are big enough to take their carbon accounting seriously but rarely have the scale to internalize that expertise. It's hard to justify building a function in-house for something that happens once a year. That's precisely why the case for outside help is strongest in the middle of the market: companies large enough that a properly detailed footprint is expected of them, but not large enough to run a full in-house carbon accounting function the way the very largest enterprises can.

 

The role for a carbon accountant

 

Specialized and carrying real liability if it goes wrong - that's precisely the kind of work that tends to get delegated to someone who is an expert in the field. We use the term carbon accountant for that person: someone who reports emissions as their actual job, across a portfolio of client companies, rather than as a task bolted onto someone's existing role once a year.

 

The value here isn't just that they know the rules. A carbon accountant handling the same categories, the same edge cases and the same regulatory changes across dozens of clients builds a pattern that a company doing this once a year for itself never gets the chance to develop. They've already seen how a similar business in the same sector handled a tricky Scope 3 category, which materiality calls tend to hold up under audit and which shortcuts don't. That repetition is also what makes the model work as a business: reporting is recurring by nature, which gives a consultancy a dependable, ongoing engagement with each client instead of a one-off project that must be re-sold every year.

 

And the relationship doesn't stop at reporting. Once a consultant has actually built and understood a company's footprint - where the emissions are concentrated, which numbers are solid and which are soft - they're in the best position to have the conversation that matters more: what the company should do to bring their emissions down. Reporting is the entry point. Advisory is where a carbon accountant becomes a genuine partner.

 

Where dedicated software comes in

 

A carbon accountant serving many clients needs a different kind of tooling than a single in-house sustainability team would. Software earns its place here by doing three things.

 

Firstly, software saves time for everyone involved. Getting raw data into a usable, calculated footprint should be fast, not a manual reconstruction project every reporting cycle. The same goes for standardized reporting. New technological and automation possibilities make it also possible for the consultant to do the ‘boring work’ more efficiently.

 

Secondly, software ensures compliance. As frameworks and regulations move, spreadsheets that were compliant last year often need real rework this year just to stay that way. Software that's third-party validated against standards like the GHG Protocol and ISO 14064-1 turns that upkeep into something the platform carries continuously, rather than something each consultancy has to re-solve on its own every year.

 

Thirdly, software provides actionable insights from the carbon data. A footprint on its own doesn't tell a client what to do next. They need help to turn those numbers into a clear view of where the emissions sit and what would reduce them fastest. That's where a consultant's role shifts from handing over a report to helping build a real climate strategy.

 

Mirroring proven industry models

 

This way of working is not new. It's close to how corporate finance has worked for decades: companies don't build in-house teams to audit their own books from first principles, they bring in accountants who rely on standardized, purpose-built accounting software instead of reinventing bookkeeping for every client. The company still owns its numbers and its accountability to the board; the accountant supplies the expertise and the judgment calls; the software is what lets the accountant do that reliably across dozens of clients rather than one spreadsheet at a time. Carbon accounting is following a similar path.

 

It's worth being precise about where this holds, though, since it’s mainly true for mid-sized companies. They are large enough to need a properly detailed footprint but aren’t large enough to justify an in-house carbon accounting function. The very largest enterprises often keep expertise in-house for their most material topics and only bring in outside specialists for specific gaps. Very small companies, constrained by budget, more often skip structural external support altogether and rely on simpler, self-service tools. It's the company in the middle where a dedicated carbon accountant makes the most sense.

 

AI doesn't change this division of work - it just makes everyone faster within it. Where AI is genuinely useful is the most repetitive part of the job: turning invoices and activity data into structured, categorized emissions data. It's good at volume and pattern-matching, but it still depends on a person for the contextual judgment calls that come up constantly in real client data - an invoice that could plausibly fall into two categories, a client-specific assumption, a call an auditor will ask about later. What AI changes is how much a carbon accountant can get through in the time they have, and how quickly a footprint comes together in the first place. It's an efficiency gain on both sides of the relationship, not a different relationship.

 

This is why we build Carbon+Alt+Delete for consultants

 

At Carbon+Alt+Delete, we've built the carbon accounting platform around this model from the beginning. We didn't set out to build software for companies to open once a year and forget about. We built it for the carbon accountant: software that supports the full carbon accounting process, is third-party validated to be compliant with the GHG Protocol and ISO 14064-1 and today underpins 200+ sustainability consultancies across Europe managing the carbon footprints of 2,000+ companies. At Carbon+Alt+Delete, we believe in building for carbon experts, by carbon experts.