Carbon Waste and Resources Metric (CarbonWARM2)

CarbonWARM2 is the latest version of the Carbon Waste and Resources Metric developed by WRAP on behalf of Defra. This updated version provides conversion factors that enable organisations to assess the greenhouse gas (GHG) emissions associated with waste management practices, expressed in carbon dioxide equivalent (CO₂e). It serves as an essential tool for evaluating and improving waste management strategies.

Building on the original CarbonWARM published in 2021, this enhanced version includes several updates:

• Material Categories: The metric now covers additional waste categories, including Waste Electrical and Electronic Equipment (WEEE), batteries, and sanitary wastes.
• Source Separated vs Commingled Recycling: CarbonWARM2 differentiates between source-separated recycling (materials separated at collection) and commingled recycling (materials collected together and sorted later), providing conversion factors for each.
• Territorial Emissions Modelling: The new model includes calculations for territorial emissions in addition to consumption-based emissions.

Envisaged applications for CarbonWARM2 include:

• Monitoring and reporting CO₂e savings achieved by shifting waste management up the hierarchy.
• Evaluating how much of the potential CO₂e savings has been realized through current practices.
• Modelling and comparing the greenhouse gas impacts of different waste management scenarios.

This metric is suitable for local authorities, waste management companies, policy makers and other stakeholders committed to reducing emissions and supporting climate action goals.