Our Low Carbon Economy Lead Charlie Leaman-Pearce shares where to start when tackling Scope 3 emissions, which often account for the majority of an organisation’s greenhouse gas footprint, are frequently the most complex, but are also often tackled last.
For organisations with complex supply chains, tackling Scope 3 emissions can feel overwhelming. These indirect emissions, often accounting for the majority of an organisation’s greenhouse gas footprint, are dispersed across suppliers, products, and services. This can make them difficult to measure and even harder to reduce. The question many organisations ask is: “Where do you start?”
Scope 3 emissions are notoriously difficult to manage because they sit outside your direct control. Data is often incomplete, spend-based, and inconsistent across suppliers. Without a clear roadmap, organisations risk wasting resources on low-impact areas or failing to meet stakeholder expectations.
At Eunomia, we’ve developed proprietary tools and proven techniques to help organisations cut through the complexity and take decisive action. Our approach combines robust prioritisation, actionable interventions, and stakeholder engagement, ensuring that your decarbonisation strategy delivers real impact. Organisations will need to answer three core questions to build a workable decarbonisation plan that delivers the greatest greenhouse gas emissions reduction for the effort invested.
What are our priority Scope 3 emissions sources?
With emissions from purchased goods and services often contributing the most significant share of Scope 3 emissions, focusing on supplier and contract prioritisation is a sensible first step. Our Low Carbon Procurement Prioritisation Tool helps organisations focus on the suppliers, contracts and spend categories that matter most. The Tool was initially developed for the UK Sustainable Procurement Task Force and published in Procuring the Future, with DEFRA adopting its use as part of the National Sustainable Public Procurement Programme. It has since been adapted by Eunomia for use in climate action planning.
To prioritise the wider Scope 3 footprint, rather than simply ranking sources by emissions magnitude, we have developed a robust multi-criteria analysis approach that also considers:
- Influence over emissions – how much leverage do you have to drive change?
- Risk forecasting – where are the reputational or compliance risks highest?
- Opportunity forecasting – which areas offer the greatest potential for innovation?
- Visibility – where is stakeholder pressure and scrutiny greatest?
- Multiplier-effect potential and interconnectivity – which actions could trigger wider change across your value chain and beyond?
This holistic approach ensures you’re not just chasing the biggest numbers, but targeting areas where action is feasible, impactful, and aligned with your strategic priorities.
What do we need to do to make change?
Once priorities are clear, the next challenge is turning ambition into action. Based on your Scope 3 footprint, we help organisations identify the physical interventions needed to reduce emissions. We then apply our Walking-Around-the Issues approach, developed with partners, to determine the conditions for success that make those interventions viable. For example, switching to purchasing low-carbon materials might require supplier availability, contractual flexibility, and internal buy-in.
From there, our Decarbonisation Action Library provides an adaptable set of practical steps to achieve those conditions. Built from experience across multiple sectors, this library offers tried-and-tested actions that accelerate progress, from contract reviews to influencing employee commuting.
How do we know we’re progressing?
Most organisations start with spend-based estimates for their Scope 3 footprints, but improving data quality is essential for accurate targeting and tracking. Eunomia’s Supplier Carbon Calculator Tool supports compliance with the UK Government’s PPN06/21 Carbon Reduction Plan, and goes further by enabling:
- Supplier-specific data collection – obtaining real emissions data to replace spend or estimates;
- Contract-level attribution – emissions per supplier; and
- Progress monitoring – tracking reductions over time.
Better data means better decisions, and the ability to demonstrate impact to stakeholders.
Our approach isn’t theoretical. We’ve worked with organisations across sectors to tackle complex Scope 3 challenges, combining technical expertise with practical tools. By integrating prioritisation, intervention design and data improvement, we help you move from uncertainty to action.
If your organisation is asking “where do we start?”, our proprietary tools – the Low Carbon Procurement Prioritisation Tool, Decarbonisation Action Library and Supplier Carbon Calculator Tool – combined with proven techniques like multi-criteria analysis and ‘Walking Around the Issues’, provide a clear, actionable pathway to decarbonisation.
If you’re ready to start decarbonising your Scope 3 emissions with confidence, please contact our Head of Low Carbon Charlie Leaman-Pearce (charlie.leaman-pearce@eunomia.co.uk).