Why should you calculate your carbon footprint?
Calculating your carbon footprint allows you to understand how you or your organisation contributes to climate change and therefore, allows you to think about and establish ways to reduce your impact on tackling climate change.
Calculating your carbon footprint annually allows you to monitor emissions over time, track and identify the how effective your emissions reduction measures emissions are. If you or your organisation has pledged to a net zero target (e.g., 2030, 2035, 2040 or 2050), annual calculations hold you to account, when progressing towards these targets.
Carbon footprints are usually calculated for financial years.
Where to start?
The first step is to identify which activities produce greenhouse gas emissions. Initially, your operation boundary must be identified, this is usually anything you have financial or operational control over. Then, you identify emissions sources from the following three emissions scopes.
- scope one: direct emissions from activities within your organisation’s control
- scope two: indirect emissions from electricity, heat or steam you purchase
- scope three: other indirect emissions from sources outside your control, such as electricity transmission and distribution losses, water supply and treatment, business travel and contractor travel
Scope one and two emissions are essential when calculating emissions and will be consistent across all organisations. However, there is a level of flexibility as to what is included in scope three.
In scope three it is best practice to include emissions from:
- transmission and distribution losses
- water supply
- water treatment
You may also wish to include the following in scope three:
- business travel
- contractor travel
- commuter travel
- outsourced activities
Data collecting and calculation
After establishing the activities that fall under your emission scopes you need to collect you activity (consumption) data. This is the raw data e.g. miles travelled, electricity consumed, fuel consumed, gas consumed etc.
This data is then multiplied by national emissions factors, so as to identify the emissions from that source. Emissions are measured in tonnes of carbon dioxide equivalent (tCO2e).
Emission factors are updated each year. See Department of Business Energy and Industrial Strategy
When calculating emissions from financial years you use the emissions factors for the year in which most of the financial year falls. For example, if you are wanting to calculate emissions for the 2021/2022 financial year, you would use the 2021 emission factors, as 9 out of 12 months fall in 2021.
Further information
The Local Government Association and Local Partnerships have together developed a greenhouse gas accounting tool.
Guidance: