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How long does it take to assess a carbon footprint?

Whether companies are assessing it to comply with legal requirements or out of a commitment to the environment, decision-makers are wondering how long it takes to assess a carbon footprint.

There is no single answer to this question. It depends on several factors, including the size of the company, its sector of activity, and whether or not the organisation calls on the services of a specialist.

However, it is estimated that the time required to perform a carbon footprint varies from 5 working days for 1 person (a service company with one office and fewer than 20 employees), to 60 working days for larger companies with several sites.

The duration varies according to the size and sector of the company

The minimum data required

The value of a carbon footprint lies largely in its completeness. Calculating a company’s carbon footprint must include all its greenhouse gas (GHG) emissions. 

These emissions include :

  • Emissions generated by suppliers upstream, 
  • Emissions generated downstream (transport, product sales, etc.),
  • Emissions linked to employee commuting,
  • Emissions linked to the final use of the product by the customer, 
  • The entire life cycle up to end-of-life and possible recycling. 

In other words, it is necessary to bring together data on the company’s activities linked to the 3 scopes of a carbon footprint: direct emissions, emissions due to energy consumption and indirect emissions. The more processes, employees and operating sites a company has, the longer it will take to collect and analyse the data.

The case of industrial companies

For industrial companies, the task is even more complex and time-consuming than for service companies. 

This is because their carbon footprint must cover all operational processes, from the supply of raw materials to the finished product, including the various stages of transformation. This generally requires the collection and analysis of data from a multitude of suppliers.

Simplified data collection reduces the duration of the carbon footprint

Since data collection is the most time-consuming phase, an optimum process needs to be put in place to collect the information efficiently and reduce the time taken to draw up the carbon footprint.

Data collection: the most time-consuming phase

A large part of the carbon footprint consultant’s work consists of gathering the information required for the carbon footprint. They spend a lot of time on this, as the information is scattered throughout the company. 

As the data needed to draw up a carbon footprint has not yet been used, there is no process for automatically collecting, harmonising and centralising it. At present, this activity is mostly manual.

Shortcuts are possible, but they reduce the reliability of the carbon footprint.

Aggregated databases

Some organisations use databases such as S&P or CDP, which offer aggregated data collected from thousands of companies to determine the quantity of CO² emitted as a function of turnover, product or asset in a given sector of activity.

However, this solution, which appears interesting at first glance, has two major drawbacks:

  • the cost of accessing this data is very high,
  • there is a lack of transparency around the source and method of calculating the information
  • the data is not necessarily applicable to the sector of the company in question.

Using the balance sheet

The balance sheet can also be used as a basis for calculating a carbon footprint quickly. Because it is compulsory and standardised, the detailed balance sheet is quick and easy to use as a starting point. There are CO² conversion factors based on the amounts spent, for example, X amount of CO² per thousand euros spent on marketing.

However, emissions calculated from the balance sheet are highly unreliable. Working based on the balance sheet implies basing your calculations on expenditure rather than on the activities that emit greenhouse gases. The result is a carbon footprint that may omit significant CO² emissions, as well as CO² conversations with a very high degree of uncertainty.

Ways to speed up the carbon footprint calculation process

Use an experienced specialist and give them access to the data

The time taken to complete a carbon footprint is shorter when it is drawn up by an experienced professional who knows how to find and analyse the data and how to convert it into CO² equivalents. Even if the external expert does not collect the data themselves, they can guide employees through the process. 

Train an in-house staff to use a carbon footprint calculator

Better still, it is possible to train an in-house person who will be responsible for collecting the data, processing it using a carbon footprinting calculator and updating the carbon footprint regularly.

This is also an opportunity for the company to put in place processes to automate the collection of data internally and from suppliers.

Note that an external consultant is also capable of training a company’s employee in data collection and the use of the carbon footprint calculator.


Explore the concept of a carbon footprint in-depth by clicking here, or read our comprehensive overview on carbon footprint calculators here.

Reduce your company’s carbon footprint by booking a demo with our experts at D-Carbonize.