You can think of scopes in terms of four categories of emissions: 

• Scope one – the direct emissions from burning fossil fuels. For road transport, these are the fuels the organisation buys and burns. These are usually diesel, petrol, liquefied petroleum gas or natural gas. 

• Scope two – the indirect emissions from the generation of purchased electricity. This includes the GHG emissions associated with generating the electricity used to charge all plug-in electric vehicles. 

• Scope three – all other indirect emissions associated with salary sacrifice cars and grey fleet vehicles. The organisation has paid for use of these vehicles, including buying fossil fuels or electricity. This means associated emissions can be considered part of the organisation’s overall emissions. 

• Out of scope – GHG emissions that cover all the biogenic emissions associated with biofuels like biomethane, biodiesel and bioethanol. These are carbon emissions produced from short-cycle carbon sources like crops.   

 If your organisation is large, you must report: 

• Scope one emissions
• Scope two emissions
• Some of the scope three emissions you have direct control over, this includes emissions associated with the grey fleet, salary sacrifice cars, rail and air travel

It might be worth reporting the scope three emissions associated with the supply chain, both upstream and downstream. It’s not mandatory, but is regarded as best practice as long as it doesn’t impact your organisation’s scope one and scope two emissions. 

You can take several measures to reduce scope one and two GHG emissions and scope three transport emissions. This includes: 

• Choosing smaller vans
• Implementing a pro-electric company car policy
• Setting carbon emission limits on the cash allowance and grey fleet

Changing the carbon emissions embedded in purchased supplies may be more challenging and have less impact.

Why do you need to use these categories?

These categories help you to avoid double counting your emissions.

For example: 

• If your organisation burns fossil fuels, you’ll report its scope one emissions
• The scope two emissions from using electricity become the scope one emissions of the generating company that burnt the gas or coal to make the electricity
• The scope three emissions associated with a train journey become the scope one emissions of the train operator who burnt the diesel to power the train

You’ll need to report scope two and three emissions because they are created by demand from the end user. For example, the electricity consumer or the train passenger creates the demand for the service. Without that demand, the scope one emissions wouldn’t be created by the service provider. 

If your company wants to reduce its scope two and three emissions, you’ll need to put pressure on your suppliers to reduce their scope one emissions.