How to measure a GHG footprint

Underpinning any organisation’s environment and climate action is a scientific understanding of its GHG carbon footprint

The purpose of this article is to explain the basic process of how to measure an organisation’s GHG footprint.  This guidance follows the principles of the ‘GHG Protocol for Corporate Accounting and Reporting Standard[1]. The GHG protocol is the most recognised and widely used international guidance when it comes to the development of GHG footprints.

Before going into the steps to develop a GHG footprint, below shows the main principles that should be followed. The GHG footprint should be:

Ensure the GHG footprint appropriately reflects the GHG emissions of the organisation and serves the decision-making needs of users – both internal and external to the organisation.

Account for and report on all GHG emission sources and activities the organisation is responsible for. Disclose and justify any specific exclusions.

Use consistent methodologies to allow for meaningful comparisons of emissions over time. Transparently document any changes to the data, footprint boundary, methods, or any other relevant factors in the time series.

Address all relevant issues in a factual and coherent manner, based on a clear audit trail. Disclose any relevant assumptions and make appropriate references to the accounting and calculation methodologies and data sources used.

Ensure that the calculation of GHG emissions is systematically neither over nor under actual emissions, as far as can be judged, and that uncertainties are reduced as far as practicable. Achieve sufficient accuracy to enable users to make decisions with reasonable assurance about the integrity of the information.

An overview of the process

Step 1

Define what emissions the organisation is responsible for

Step 2

Identify and collect relevant data

Step 3

Calculate GHG emissions from the data

Step 4

Communicate your findings

Define what emissions the organisation is responsible for

Before starting it is important to clearly define what emissions you are responsible for, i.e. the boundary of the GHG footprint.

What timeframe should be considered?
GHG emissions are typically for 12 months but can be for a shorter period.

What sources of emissions should be included?
There are three categories of GHG emissions. These are called Scope 1 (All direct emissions), Scope 2 (Indirect emissions) and Scope 3 (All other indirect emissions).

What control do you have of emissions?
An important concept to be aware of in drawing scope 1, 2 & 3 boundary is that of control – what does the organisation influence? Control can be defined in either financial or operational terms and it helps identify emissions associated with operations, categorising them as direct and indirect emissions.

What buildings / sites should be included?
In general, any buildings or sites that are used to add value to the business, e.g. through direct contact with customers, back-office processes, or distribution centres.

Identify and collect relevant data

Once you know the emissions sources that are relevant to the organisation and what’s to be included in the GHG footprint, the next step is to understand what data is needed and what is available. Data can vary, but typically most information needed can come from landlords, energy suppliers, suppliers, and expenses. Example Scope 1 & 2 data sets are shown below.


Electricity use per office

  • Meter reads
  • Billing data
  • Estimates from average
  • energy use
  • Energy supplier


Gas use per office

  • Meter reads
  • Billing data
  • Estimates from average energy use
  • Energy supplier

Fleet/company cars

  • Aggregated fuel receipts 
  • Purchase records
  • Number of miles, kilometres, Vehicle type and model year

Fugitive emissions

  • Details on air conditioning equipment

Calculate GHG emissions from the data

Different data that is collected can require different methodologies to calculate GHG emissions. In general, calculating emissions requires the following calculation:

Activity data (unit) × Emissions factor (tCO2e per unit) = Emissions (tCO2e)

Activity data could include data from the examples above. “CO2e” or “Carbon dioxide equivalent” is a term for describing different greenhouse gases in a common unit. For any quantity and type of greenhouse gas, CO2e signifies the amount of CO2 which would have the equivalent global warming impact.

Communicate your findings

Show stakeholders the ability to understand the organisation’s primary environmental impact by putting the calculated GHG footprint in your communications, marketing and reporting.

How can Borrowed Time help?

We have helped many clients develop their GHG footprints, whether it is getting started for SMEs or building full footprints for large multinationals. We also help make sure that the findings are distilled in a way that is authentic to the organisation. We have experience in the sectors of Retail, Finance, Brewing, Transportation.

1: World Resources Institute and the World Business Council for Sustainable Development (2004, revised edition).