Calculating Scope 3 Emissions
How to calculate Scope 3
In this section you will see each of the 15 categories listed as Scope 3 under the GHG Protocol, toggle between Upstream Activities tab or Downstream Activities tab to see the respective categories.
- Purchased Goods and Services
- Capital Goods
- Fuel and Energy-Related Activities
- Upstream Transportation and Distribution
- Waste Generated in Operations
- Business Travel
- Employee Commuting
- Upstream Leased Assets
- Downstream Transportation and Distribution
- Processing of Sold Products
- Use of Sold Products
- End-of-life treatment of Sold Products
- Downstream Leased Assets
- Franchises
- Investments
You can learn about each of these categories in the Introduction to Carbon Accounting Course in Sumday Academy
Calculating Scope 3 Emissions
- Go to Assessments in the left hand menu.
- Go to Accounting
- Go to Scope 3
- Create worksheets within the respective emission categories.
- Add consumption data into the table where possible. If you don’t have this data, that’s alright, you can tag the transactions as ‘Spend based’.
The visual for each of the subcategories outlines the method applied for each of the transactions. The three categories displayed are:
- Spend based - these are transactions where the financial value of the transaction has been used to determine the emissions. Where an activity based factor does not exist in Sumday’s database for an emissions source selected in the carbon ledger a spend based EF will be applied automatically.
- Activity based - Where an activity based emissions factor is available for the emissions source selected you can replaced the spend based calculation with an activity based factor. To do this you will need to select “Calculations” and then create a worksheet to enter the activity based amounts for each transaction. these could be litres, tonnes, etc. Using activity based emissions factors will generally result in higher data quality.
- Unassigned - where both spend and activity based emissions factor options exist for a given emissions factor source then you will need to determine which approach you will be adopting. if you will be using spend than you can click the “tag unassigned as spend based” to automatically assign those transactions. If you are using spend based then you will need to create a workbook and enter the activity based values for each of the transactions. It is important to note that you will not be able to finalise the GHG inventory in Sumday until all transactions are assigned.
When you click on the Assign transactions in this view you will be taken to the detailed worksheets associated with each of the emissions sources to do an activity based calculation, this is where you will enter activity data such as quantities purchased.
If you don’t have activity data, you can “tag unassigned as spend based” to confirm the spend based approach is being applied to these transactions.
If the approach changes during the assessment you can always unassign transactions and recategorise or tag as spend based.
What data do I need to calculate?
Here’s a table with the information you need for each category.
Some of this can be found in accounting or ERP systems, and some might be data your organisation has never collected before and that’s alright! Just make a start! Often finance teams have a good understanding of where, which function, and who might be best to go to collect this data.
You can learn more in the Introduction to Carbon Accounting Course in Sumday Academy
Category | Data | Data Sourcse |
Purchased Goods and Services | Start with: Importing transactions for the reporting period from your accounting system. Easily export the details into excel and upload them - ask your accountant for help if you need it or reach out.
Enhance this data: Using quantity of goods purchased or hours of service received | Purchase orders, receipts, invoices, contracts
Financial transactions for the reporting period which can be easily exported from your accounting system. |
Capital Goods | Quantity of goods purchased. | Purchase orders, receipts, invoices, contracts. Fixed asset register. |
Fuel and energy-related activities | Amount of fuel used
Energy purchased (e.g., kWh of electricity, therms of natural gas) | Invoices / Utility bills
Metre reading records
Contracts such as PPA (Power Purchase Agreements)
Fuel purchase receipts |
Transportation and Distribution | Distance and mode of transport
Mass or volume of products shipped
Site specific fuel and electricity usage and emissions | Invoices Fuel receipts
Delivery notes / Transit records |
Waste generated in operations | Total waste produced and type e.g. tonne/cubic metre
Proportion of this waste being treated by different methods (e.g., percent landfilled, incinerated, recycled) | Utility bills
Tracking systems |
Business travel | Destination and distance travelled by modes of transport
Nights of accommodation
Amount of fuel used | Travel agency records
Travel providers e.g. airline
Reimbursement receipts e.g. Fuel purchased
Surveys with staff |
Employee commute and WFH | Headcount
Days travelled to work and mode of transport
Amount of fuel used
Number of WFH days
Electricity and fuel used, apportioned, from WFH | HR records
Surveys with employees |
Leased Assets | Type and number of leased assets or proportion of leased area of building
Scope 1 and 2 emissions associated with lease | Lease records
Utility bills |
Processing of sold products | Fuel and energy used related to the site
Scope 1 and 2 emissions (e.g. Process and fugitive emissions if applicable) related to the site | Invoices / Utility bills
See Scope 1 and 2 for other potential sources |
Use of sold products | Total lifetime expected uses of product(s)
Quantities of products sold
Fuel used/Electricity consumed/Refrigerant leakage per use of product | Sales records / Invoices
Product specifications or manuals |
End-of-life treatment of sold products | Total mass of sold products and packaging (from point of sale till consumer i.e. includes any packaging that was used to transport)
Proportion of this waste being treated by different methods (e.g., percent landfilled, incinerated, recycled) | Sales records / Invoices
Product specifications or manuals
Tracking systems |
Franchises | Emissions franchisee entities
Fuel and energy use by facility | Utility bills
Rent statements and lease records |
Investments | Proportion of share in investment
Emissions from portfolio companies | Investment records |
Common questions on the Emissions Overview
Why is the “tag unassigned as spend based” greyed out?
This happens for two reasons:
- There are no unassigned transactions. if you need to allocate a transaction to spend you will need to first unassign the transaction from the worksheet and then it will be available to tag as spend.
- There is no spend based emissions factor for this particular emissions source. In this instance you will need to input the activity based information required or unreconciled the transaction and choose another emission source where you do have the required input.
Why do I need to code the transaction in the carbon ledger and then reassign the transaction in the individual worksheet?
Sumday has a focus on auditability and as a result a key element of being auditable is ensuring that the emission calculations are complete and there is a clear trail from start to finish. This means that the process start with the financial transaction record which then flows through to the rest of the carbon accounting process. Where the initial spend based calculation method is being replaced with an alternative unit of measure, this process happens as part of a separate worksheet-based step to ensure the audit trail is maintained while making changes to the calculation.
It can feel like a bit of extra work to carbon account but a seperate systematic workflow can often add efficiencies, and the final result is auditable and you are less likely to miss transactions as part of the process.
Last updated on September 4, 2024