What types of data can I use to calculate scope 3 emissions?
Companies can use two types of data to calculate scope 3 emissions:
Primary data: Data from specific activities within a company’s value chain, such as fuel consumption data provided by suppliers or customers.
Secondary data: External data not tied to specific activities in the company’s value chain. This includes industry averages, government statistics, financial data, proxy data, and other information. Proxy data, which is used to estimate emissions for one activity based on data from another, is also considered secondary.
Can I estimate Scope 3 emissions if my suppliers do not provide data?
Yes, if supplier emissions data or product specific PCFs are unavailable, companies often rely on economic intensity factors, industry or product average emission factors, or lifecycle assessment tools to estimate Scope 3 emissions.
How do I get accurate data from my suppliers?
You can request emissions data from suppliers, encourage them to report their GHG emissions, and collaborate with them on sustainability initiatives. Alternatively, use tools like surveys or emission databases to estimate emissions based on supplier characteristics. The Make it Zero initiative is working to develop tools to support the provision of emissions-related data from suppliers
How should I start to measure the emissions embodied in the products I sell? (captured within Scope 3 Category 1)
Start by cataloguing your products into suitable groupings such as the sector they come from and the materials they consist of. Then, use spend-based conversion factors combined with the cost of the goods to estimate the emissions that occurred in their supply chain to your store. An alternative to this is to calculation your share of the supplier’s own scope 1,2 and upstream 3 emissions, effectively forming a spend-based emissions factor for that given product supplier.
Once you have identified the products that contribute the most to your emissions, you can work to improve the granularity and robustness of the calculations.
You can better estimate emissions based on product material quantity and then using secondary data like industry averages or life cycle databases (e.g., from Ecoinvent). Calculate emissions by multiplying product quantities by appropriate emissions factors (e.g., CO2e per kg). Consider the entire supply chain, including upstream activities like raw material extraction and transportation, using tools like the GHG Protocol.
For greater accuracy, use Product Carbon Footprints from your suppliers, or consider generating your own emissions estimates using Life Cycle Assessment (LCA) tools. More information can be found on Measuring scope 3 emissions and in the Scope 3 Accounting Guidance[DC1] .
How can I improve accuracy of Scope 3 emissions accounting over time?
To improve Scope 3 emissions accuracy over time, replace low-quality or proxy data with more precise primary data, especially from key categories like purchased goods and transportation. Update emission factors annually and refine your methodology as better data becomes available. Seek Product Carbon Footprints from suppliers.
How can I track Scope 3 emissions from online sales?
The same as for any retail sales. For e-commerce, track emissions from packaging, shipping, and returns, as well as emissions from your data centres and digital infrastructure. You can estimate emissions using emission factors for logistics and energy use associated with online operations. If you function as a marketplace for third parties to sell goods, the situation is more complex and is the subject of ongoing research by Make it Zero.
What is the difference between Transport categories 4 and 9?
Category 4 includes inbound and outbound transport – if you pay for it. Category 9 refers to transportation of products once they have left your responsibility- such as collection and transportation from your store or warehouse by customers.
Do I need to report on business travel and employee commuting?
To form a complete scope 3 inventory, yes, they should be included, albeit they are unlikely to be among the major scope 3 emissions sources for a retailer. Both activities fall under Scope 3 because they are indirect emissions that result from employee activities linked to operations. Tracking and reporting these emissions helps provide a more comprehensive view of a company's environmental impact across its value chain.
How do I track Scope 3 emissions from product use? (Category 11)
For products that consume energy during use (e.g., electronics, appliances), estimate emissions based on usage patterns, average energy consumption, and regional energy mixes. This can be done through lifecycle assessments or by using emission factors for similar products. For further information see the Scope 3 accounting guide
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