Calculating and reporting your fleet’s greenhouse gas emissions

There are multiple factors to consider when planning to decarbonise your fleet. The first step is to calculate your current fleet emissions. This will give you a baseline to work from and help you identify where you can make carbon savings.

Your organisation’s carbon dioxide equivalent (CO2e) footprint, or carbon footprint, is the amount of greenhouse gases (GHGs) it emits in one year, measured in tonnes.

For road transport, the reportable GHGs are:

• carbon dioxide (CO2)
• methane (CH4)
• nitrous oxide (N2O)
• fluorinated gases

Methane and nitrous oxide are reported in terms of their carbon dioxide equivalence using their global warming potential (GHG Protocol, GWP Values). It’s important to report your CO2e emissions as well as your CO2 emissions. This will ensure you meet national and international GHG reporting standards.

You can report your road transport GHG emissions using tank-to-wheel emission factors. These exclude any CO2e emissions relating to the extraction, refining and distribution of fuels, known as well-to-tank factors. They also exclude emissions associated with the manufacture and disposal of vehicles.

Well-to-tank emission factors can be combined with tank-to-wheel factors to give well-to-wheel values. However, the fuel supplier should report the upstream emissions associated with the well-to-tank stage.