Southwest Environmental Limited

Scope 1, Scope 2 and Scope 3 Emissions

Some green house gas emissions are easier to calculate than others, as you remove the distance from "you" to the emission you want to measure in terms of supply chain it become more difficult to calculate. That is why industry guidance suggests splitting carbon emissions in to Scope 1, Scope 2 and Scope 3. It offers up some low hanging fruit in the forms of Scope 1 and Scope 2, without entering the morass that is Scope 3.

The below table has been copied from the DEFRA SECR Guide:

Scope 1 (Direct) GHG Emissions

"These are perhaps the easiest emissions to calculate and can be worked out from you Gas bill, or in more exotic cases sales invoices (including quantities) for bio-mass fuel imports. If you are burning other wastes we can help to provide an emissions factor. "

These include emissions from activities owned or controlled by your organisation that release emissions into the atmosphere. They are direct emissions. Examples of Scope 1 emissions include emissions from combustion in owned or controlled boilers, furnaces, vehicles; emissions from chemical production in owned or controlled process equipment.

Scope 2 (Energy indirect) Emissions

"These include emissions released into the atmosphere associated with your consumption of purchased electricity, heat, steam and cooling. These are indirect emissions that are a consequence of your organisation's activities, but which occur at sources you do not own or control."

These can be easy to calculate also. Typically you might use an emissions factor to convert you KWh total from electricity usage, thing might become more complicated where you import heat or electricity from a district heating scheme or similar, as their emissions factors made not be present or will need calculation.

Scope 3 (Other indirect) Emissions 

"Emissions that are a consequence of your actions, which occur at sources which you do not own or control and which are not classed as Scope 2 emissions. Examples of Scope 3 emissions are business travel by means not owned or controlled by your organisation, waste disposal which is not owned or controlled, or purchased materials."

This $h!t just got real. Things will get complicated here, and for most this will start to include things such as materials and labor. As the complexity increases so does potential inaccuracy. It is likely that Scope 3 reporting will become easier over time as carbon reporting becomes more wide spread. In the future companies may well be able to offer a metric such as CO2e per m2 or kg of product that goes through your system which would then be passed up the reporting chain.

Again for scope 3 activities that have not been independently foot printed, then emissions factors can be used to estimate carbon footprint for example a company that uses corrugated roof sheeting might estimate foot print for Scope 3 emission based on emissions factors for steel and zinc, and apply an overage for manufacturing carbon, based on energy use over a year divided by production over the same period.

One option that we have used to simplify this step, and at least start to quantify Scope 3 emissions is input / output modeling. This uses a conversion factor based on expenditure. It is not very accurate, but can give companies and organization as idea of what their emissions are. 

Scope Shift

It is quite possible and allowable to shift emissions from Scopes 1 and 2 . . . to Scope 3. One example might be the trend of the last decade to shift Scope 2 emissions for running a data server at you offices, to cloud computing, which would be Scope 3.

Not so long ago a business might have its own server room. A small room filled with computers and cooling equipment. But as from about 10 years ago services such as Google Cloud, or Amazon Webservices made it possible to outsource you server requirements, and with it you emissions too.

In this way organisations report server emissions as Scope 3 emissions. And for many companies, they do not report Scope 3 carbon emissions at all. So the carbon emissions are "hidden in the cloud".

Scope 1, 2 and 3 Examples

Scope 1 - Burning Gas in a Boiler to heat you offices.

Scope 2 - You electricity bill. Emissions are created at power station.

Scope 3 - Printer toner cartridges. You will need to work this out, based on the parts of the toner cartridge, and there weights, or use an input out / model for voluntary reporting.