Downstream Emissions
This category is about understanding and assessing the impacts arising from the use of an organisation’s digital estate by end-users. Downstream impacts (Category D) are produced by the use an organisation’s digital products and services. This could be other businesses or the public, and are usually external to your organisation. Typically these are impacts attributed to the devices of end-users and the transmission of data to use that product or service.
Downstream emissions are related to GHG Protocol Scope 3.
For most organisations, the majority of their impact reduction opportunities are outside their own operations and lie in the downstream emissions category. Assessing downstream emissions is an important part of prioritising efficiency work within a digital estate.
End-User Devices
This considers the impacts generated by the resource consumption of devices such as desktops, laptops, tablets, mobile phones and TVs that utilise the products or services provided by an organisation.
Product metrics and web analytics tools usually provide information for understanding the number of users, where they are located, the types of devices used and the time spent using a product or service.
Network Data Transfer
These impacts are associated with the infrastructure enabling data transmission, enabling end-users to access the products and services. NB: as the power usage of networking equipment has very little variance while it is running, attributing the power consumption to specific applications or processes is less important.
Data that is consumed over the Internet is hard to measure as the specifications of the equipment used over the public internet are not available. Even if that data was available, the system has no control over what route the data takes. Therefore it is appropriate to use a proxy such as:
- number of calls
- payload size
- the distance transmitted
- the carbon intensity of the regions through which the data is transferred
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