Waste Methodology in the Carbon Navigator

Overview

The Carbon Navigator calculates emissions from the waste your organization generates in its operations and pays a third party to handle — for example, the trash, recycling, and compost collected from an office or facility by a waste hauler, or industrial waste from a plant you own or control.

Waste sits in Scope 3, Category 5 (Waste Generated in Operations) under the GHG Protocol, the standard the Carbon Navigator is built on. As with every category, each waste calculation carries the underlying emissions factor and source so the result is transparent and auditable.

How emissions are calculated

There are two ways to account for waste in the Carbon Navigator. You can use either, or a mix, depending on the data you have available.

Method	When to use it	How it works
Activity-based	You know the type and quantity of waste and how it was disposed of.	You enter the waste type, the amount (by weight), and the disposal method, facility by facility. The Carbon Navigator applies the matching emissions factor for that combination.
Spend-based	You only have supplier spend (e.g. an invoice from a waste hauler).	Reclassify the relevant supplier's spend from Purchased Goods & Services (Category 3.1) into Waste (Category 3.5). Emissions are then estimated from the amount spent.

The activity-based method is more precise because it reflects the actual materials and disposal routes rather than a spend estimate. Where you have the underlying waste data, it is the recommended approach.

Activity-based inputs

For the activity-based method, you provide the following for each facility:

Waste type — for example general, construction, or hazardous waste.
Amount — the quantity of waste, by weight.
Disposal method — how the waste was handled, such as recycled, landfilled, or incinerated.

The combination of type and disposal method matters: the same quantity of waste can produce very different emissions depending on how it is treated. Recycling a given material typically carries a much lower factor than sending it to landfill or incineration.

Emissions factors

Waste emissions factors are sourced from the UK Department for Business, Energy & Industrial Strategy (BEIS) and served through the Carbon Navigator's emissions-factor partner, Climatiq. The Carbon Navigator selects the appropriate factor for the waste type and disposal method you enter.

A couple of practical notes:

Emissions-factor coverage for hazardous waste is more limited than for general waste. Some disposal routes for hazardous waste may not have a directly matching factor, in which case a workaround or an offline calculation may be needed.
Materials are mapped to the closest BEIS category. For example, untreated wood such as wooden pallets falls under construction waste in the BEIS classification.

What is included in total waste generated

Total waste generated includes both waste directed to recovery (recycled) and waste directed to disposal (end of life). Recycling is counted — it is not excluded from the total. For more detail, see What is included in my total waste generated?

A note on materiality

In most portfolios, waste generated in operations accounts for well under 5% of the total carbon footprint. In line with the GHG Protocol's guidance on materiality thresholds, an estimate is often sufficient for this category, and the effort of gathering highly granular waste data may not be warranted unless waste is material to your business (as it can be for large industrial or chemical companies).

Last updated: August 20, 2026