Calculating your footprint
Wendy Buckley explains how to start measuring an organisation's greenhouse-gas emissions
The term “carbon footprint” has become common in environment management and is seldom off media or boardroom agendas. It is a measure of the impact business activities have on the environment in terms of the amount of greenhouse gas (GHG) produced, calculated in units of CO2 equivalent (CO2e). Organisations need to assess and manage their carbon emissions, not just to meet regulatory needs and to save energy costs, but to give competitive advantage. So, what are the practicalities of measuring your footprint?
What to measure?
Clearly the pressure is on for businesses to assess their carbon footprints. But what needs to be reported and measured? First, you need to make a decision on whether you should calculate your organisational footprint or product/service footprint.
Organisational footprinting is the main focus of this article , and is usually repeated on an annual basis. However, products and services can also be quantified and best practice for this is the Publicly Available Specification 2050 (PAS 2050), also known as product life cycle analysis (LCA). LCA calculations take into consideration emissions associated with:
- sourcing raw materials and their transportation;
- the production, manufacture and packaging of goods; and
- their distribution, retail, use and end-of-life.
By their nature, LCA calculations are far more involved than organisational carbon footprint projects and the former often involve weeks – even months – of work (and cost!) depending on product/service complexity and access to supply chain partner data.
How to calculate your footprint
Once you have decided on what to measure, the process for measuring and managing your carbon footprint includes the following key steps:
- Define the organisational boundary.
- Collate all source data (include all GHGs, not just carbon dioxide).
- Perform calculation (using Defra metrics).
- Analyse and benchmark performance.
- Input results into carbon management plan.
- Report.
An organisational carbon footprint is based on the emissions of the business. The methodology for footprinting is described by ISO 14064 and the GHG Protocol defines the scope of these emissions. You must establish at the outset realistic “operational boundaries” for your calculations; these boundaries should always be disclosed when you report your carbon footprint.
There are two main types of emissions: primary and secondary. Primary emissions are those that can most realistically be controlled and managed. Calculating and managing secondary emissions is much harder, but you should be considering your secondary emissions if at all possible.
There are two principal causes of emissions: the energy used in buildings and travel emissions. This encompasses electricity use, burning oil or gas for heating, and fuel consumption as a result of business travel or distribution. The primary footprint corresponds to elements within scopes 1, 2 and 3 of the GHG Protocol.
The secondary footprint is a measure of the indirect emissions from a company’s upstream and downstream activities, typically from outsourced/contract manufacturing, and products and services offered by an organisation. The secondary footprint corresponds to scope 3 of the GHG Protocol, excluding employee business travel (see table below).
Primary footprint | |||
| Activity | Scope | ||
| Electricity, heat or steam generated on-site | 1 | ||
| Natural gas, gas, oil, LPG or coal use attributable to company-owned facilities | 1 | ||
| Company-owned vehicle travel | 1 | ||
| Production of any of the six GHGs | 1 | ||
| Purchased electricity, heat or steam | 2 | ||
| Employee business travel (using transport not owned by the company) | 3 | ||
Secondary footprint | |||
| Activity | Scope | ||
| Employee commuting | 3 | ||
| Transportation of an organisation’s products, materials or waste by another organisation | 3 | ||
| Outsourced activities | 3 | ||
| GHG emissions from waste generated but managed by another organisation | 3 | ||
| GHG emissions from the use and end-of-life phases of an organisation’s products/services | 3 | ||
| GHG emissions arising from the production and distribution of energy products, other than electricity, steam and heat, consumed by the organisation | 3 | ||
| GHG emissions from the production of purchased raw or primary materials | 3 |
It is more typical for organisational calculations to focus on the primary footprint, as this lies under its control. You will need access to information on all these datasets to compile your carbon emission calculation.
If this seems onerous, then don’t lose sight of the fact that typically businesses waste 30% of all energy they use, which is a huge potential cost saving that can only be identified by following this process. However, while datasets on building energy use are easily found, travel data can be harder to locate and more fragmented – data is often held within finance teams and sometimes within human resources, if it relates to claimed expenses.
Once you have all the relevant data, it needs to be converted from its native units – for example, kWh of electricity and gas or litres of diesel fuel – into tonnes of CO2e. This involves applying the appropriate carbon emission metrics. Defra publishes these on a regular basis.
Although the calculation seems easy, the complexity of the organisation will determine the time and resources you need to complete the assessment. Other complexity arises if your business shares facilities with other parties, for instance, or you need to apportion carbon to a particular business subsidiary from its corporate parent.
A number of carbon footprint measurement software tools are available; some are free to use and available online and others are geared towards particular sectors, such as manufacturing. There is also a range of commercially available carbon management software now emerging in the marketplace. The best tools use ISO 14064 methodology, the GHG Protocol and metrics from a recognised database, such as the Defra one.
The results
A simple pie chart or bar chart representation is often the easiest way to interpret your current emissions status (see example right). This will provide a snapshot of your current performance and enable the organisation to prioritise resources in areas contributing most heavily. The example footprint reveals that emissions from electricity consumption dominate.
This might indicate significant overnight electricity draw from the building. Possible causes, such as lighting or PCs being left on, should be investigated in this instance.
It is also valuable to benchmark current performance against other similar businesses. Although current data resources are a little patchy, useful data is becoming available and is commonly expressed in terms of tonnes of CO2 per employee/by sales turnover.
Once you have completed your carbon footprint calculation, use it as a baseline emission level for targets and monitoring ongoing performance.