Foreword

The report positions Scope 3 emissions as a major challenge for organisations, typically accounting for 80–95% of total emissions. While difficult to measure and control, Scope 3 data is essential for identifying emissions hotspots and prioritising reduction strategies. Although Scope 3 reporting is currently voluntary in the UK, regulatory momentum is increasing through the EU Corporate Sustainability Reporting Directive and California’s Climate Corporate Data Accountability Act, with UK adoption of ISSB standards expected.

Introduction

Scope 3 covers 15 upstream and downstream categories across the value chain and requires extensive internal and external collaboration. The report draws on insights from a 2024 UN Global Compact Network UK webinar series, highlighting practical methods, tools and peer learning to support companies in collecting, managing and using Scope 3 data to inform decarbonisation.

Supplier engagement

Effective Scope 3 data collection depends on strong supplier engagement, as data is largely derived from suppliers’ Scope 1 and 2 emissions. Companies are moving from spend-based estimates towards supplier-specific and product-level data, including lifecycle assessments (LCAs). Evidence from CDP shows disclosure drives action: 69% of third-time supplier disclosers have emissions reduction initiatives, compared with 38% of first-time disclosers. Case studies (Hempel A/S and Forster Communications) demonstrate structured supplier programmes, screening for maturity, feedback loops, and integrating sustainability into procurement decisions. Key actions include early engagement, coordination to avoid supplier fatigue, and accepting imperfect data to enable immediate reductions.

Upstream emissions

Upstream categories, particularly purchased goods and services, often dominate Scope 3 footprints. The report outlines hybrid approaches combining supplier data, product LCAs and spend-based estimates. AstraZeneca uses product-specific LCAs for over 80% of relevant emissions, supplemented by supplier intensity factors and industry averages where data gaps exist. Vodafone UK reports that 98% of its UK emissions are Scope 3 and uses primarily spend-based data managed through simple tools, supported by third-party verification. National Grid reports approximately 28 million tonnes of CO₂ annually from Scope 3, applying a hybrid approach while prioritising rapid decarbonisation over data perfection. Key learnings include focusing granular data collection on material categories and tailoring methods to supplier complexity.

Downstream emissions

Downstream emissions arise from transport, product use and end-of-life treatment. The report compares fuel-based, distance-based and spend-based methods, highlighting trade-offs between accuracy and data availability. Philips applies detailed methodologies for transport and product use, combining internal logistics data, emissions factors and assumptions on product lifetimes, with devices ranging from four to ten years. FLSmidth reports that up to 99% of its emissions come from product use, using detailed activity data and planning to incorporate electricity decarbonisation factors. Key actions include prioritising material categories, starting with low-tech solutions, and progressively improving data quality.

Employee engagement

Employees play a direct role in Scope 3 categories such as business travel and commuting, and indirectly influence purchasing and waste. Case studies show a range of approaches, from AVL’s exploration of automated travel tracking tools to Clyde & Co’s shift from manual, assumptive data to improved systems supported by employee engagement campaigns. Whatley Manor embeds sustainability into training and incentives, supporting accurate data collection and behavioural change. Key learnings stress clear communication on why data is collected, transparency on data use, and embedding sustainability responsibilities across roles.

Final takeaways

The report concludes that while Scope 3 data collection is complex, practical guidance and tools already exist. Companies are encouraged to start with material categories, prioritise collaboration, and balance data accuracy with timely action. Consistency, transparency and a focus on emissions reduction—rather than perfect data—are emphasised as critical to progress.