How to Measure Carbon Emissions

Are you wondering about how to calculate your organisation's carbon emissions? In this article we take you through the points you need to consider when measuring your company's carbon footprint
Co-founder of Positive Planet.

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Measuring Your Carbon Emissions

An organisational carbon footprint calculation is an essential step on your pathway towards net zero emissions and is the starting point for any sustainability strategy.

In this article, we’ll take you through the steps you need to take to measure your emissions and help you to understand key carbon accounting terminology. We’ll also discuss the pros and cons of measuring your carbon emissions.

Can I measure emissions myself or should I get specialist help?

You have three options when it comes to calculating and understanding your carbon footprint:

  1. Measure it yourself using a spreadsheet or free online tools
  2. Use a software platform to measure it yourself
  3. Use a specialist agency such as Positive Planet to do it for you
It won’t be a surprise that I favour option three, but I will explain why it is the most cost-effective and safe choice for your organisation. We speak to a lot of people who have started down the path of trying to measure their carbon emissions only to find that it is way more complicated than they initially imagined. They waste significant amounts of time trying to understand what needs to be calculated, working out the formula to calculate the emissions and then finding the emission factors. The emission factors are the critical part of the calculation that turns your data into a measure of CO2e (carbon dioxide equivalent). If you get any part of the equation wrong, your calculation will be incorrect.
We get similar feedback from clients who have tried using a software platform. Invariably people find it easy at first, but the problems occur when you need help and support. Software platforms may be the right choice for small businesses with simple carbon footprints, but if you have a complex operational model, using a specialist agency is probably the best route for you.
This brings us to the option of using a specialist agency. Our research shows that most organisations don’t have the expertise or time to measure their carbon footprint; however many are also concerned about the cost of using a consultancy assuming wrongly that they will be charged £1,000’s. The reality is that using a specialist will not only save you time and money but will also benefit significantly from the additional support you receive. 9 out of 10 self-calculated carbon footprints we review are incorrect, often significantly under or over-reporting emissions.
In 2024/25 carbon footprint disclosures will become mandatory for businesses of all sizes. You will be required to submit details of your carbon footprint to HM Treasury as part of your annual business reporting. If you use an accountant for your financial reporting, I advise that you seek the advice of a professional for your carbon reporting.

What are emissions scopes?

Carbon footprints capture greenhouse gas (GHG) emissions outputs on an annual basis. Data will need to be gathered from a variety of different sources including travel, logistics and operations in order to gather a full and accurate footprint.

Data collection for Scope 3 emissions involves multiple stakeholders and data sources. This makes them more challenging but Scope 3 emissions are important as they often account for a significant proportion of a company’s carbon footprint – sometimes up to 90%. Examples of Scope 3 include business travel, employee commuting or emissions arising from the use of sold products but also upstream activities including raw material and agricultural production.

By breaking down your emissions into sources, you can find the hotspot areas where emissions reductions need to be focused and use this to identify areas of risk and opportunity for your company.

What data is required to calculate carbon emissions?

Calculating your carbon footprint will require data from a wide range of sources across your organisation. This may seem daunting at first, but a specialist partner will help you to identify what information is needed and will also have ways of simplifying the collection process to reduce your workload. Positive Planet take our clients through an onboarding process that enables us to identify what needs to be measured, what is significant and what data is required to support a robust and accurate calculation. We assess, validate and benchmark your data for quality and completeness in order to determine the robustness of your final carbon measurement. 

It’s also important to ensure that your data is for a consistent time period, for example if you are doing an annual footprint then all data must be for the same boundaries. Ultimately, each organisation is different and therefore has differing material emission sources (the largest or most significant to business operations). A small office-based company’s energy use may be dwarfed by its business travel, for example.

It is worth pointing out that you will need to collate data whether you measure your carbon emissions yourself or get someone else to do it. In the section below I’ve broken out the typical information you will need for each emission scope. 

Scope 1

  • This will only apply to companies who use gas, have company vehicles or use other fuels for heating or transport. You must aggregate your fuel usage from invoices, receipts or other records.
Scope 2
  • You require information on your electricity usage for the measurement period and an understanding of whether it is green energy from renewables, fossil fuel-derived energy or a mix. 

Scope 3

  • Scope 3 covers a much broader range of information and is more difficult to calculate. 
  • Purchased goods and services and capital goods require data across all your expenditure across the reporting period (excluding energy, gas, and fuel for company vehicles). Most companies will have this information well structured and easily accessible via your accounting software or management accounts. 
  • Business travel and commuting– Travel information can normally be obtained from expense claims or a travel booking platform. You need to categorise information by type of transportation used and record the total distance travelled. Employee commuting can be calculated through a staff survey and supplemented with data on national commuting habits. You need to understand the distance travelled and the modes of transport used along with the frequency of travel for each employee. Homeworking also forms part of your calculation so you will need information about patterns and behaviours of your employee’s work life. 
  • Waste and water information can generally be acquired from invoices. 
  • Data to measure transport and distribution of goods, both upstream and downstream will require knowledge of the size and weight of what is being sent, plus mode of transport and distance travelled.  
  • For most organisations investment calculations will be limited to company pensions, however banks, building societies, private equity companies and other organisations who invest money on behalf of others will need to measure scope 1 and 2 emissions across their investment portfolio. 
  • Calculating emissions relating to processing of goods, use of sold goods and ens of life treatment of sold goods is best left to specialists as it requires significantly more research and complex calculations. 

How to calculate carbon emissions

Now that you have your data, you will need to select a methodology for your footprint that is most relevant for your organisation and ambitions. GHG Protocol is the most widely used and recognised methodology – it is what we mainly use at Positive Planet.  Other organisations such as PAS (PAS2050) and ISO (ISO 1400) are also available for specialist calculations but they are all broadly similar in their approach. 

The choice you make will depend upon the data that you have collected, as well as what you plan to do with the findings.

Once you have decided on a protocol, you will need to obtain the emissions factors required to convert your company data into tonnes of CO2 emitted (tCO2e). These will be specific to the country emissions were released. Most international governments produce a list of emission factors covering common data points. These are updated annually so you will need to ensure you use the correct data set for your measurement year. 

The final stage is to analyse your findings and create an emissions report. The output from your report will help to guide your actions to reduce your emissions and create a carbon reduction plan or net zero roadmap, 

How to calculate carbon emissions

It typically takes Positive Planet 6-8 weeks to calculate a company’s carbon emissions, but we can get through the process faster if required. Our experienced team and robust methodology ensure that your reporting is accurate so that you can share your results with confidence. Measuring your emissions can be hugely time-consuming and frustrating and frequently leads to disengagement in your sustainability goals. 

Further reading

What are scope 1, 2 & 3 emissions?

Scope 1, 2 and 3 emissions form the framework of your carbon footprint. Understand which scopes you will need to calculate for your carbon footprint. 

About us

Positive Planet support small to medium sized businesses to measure and reduce their carbon emissions . We support your pathway to net-zero with hands on support and affordable services. 

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Co-founder of Positive Planet.

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