Scope 3 emissions sit at the heart of any credible climate strategy. That’s because emissions from the value chain make up the vast majority of a company’s total greenhouse gas emissions. CDP data shows upstream supply chain emissions alone average 11.4 times greater than a company’s operational emissions.

Yet, according to a survey by the Science Based Targets initiative (SBTi), scope 3 is the biggest roadblock to setting science-based targets. For most companies, it’s because scope 3 emissions are concentrated across a long tail of SME suppliers.

With 2030 approaching, sustainability teams face growing pressure to move from ambition to measurable progress - whether that means setting near-term science-based targets (SBTs) or delivering on existing ones. That puts supplier data collection across SME suppliers firmly in the spotlight. As companies tackle this challenge, three persistent barriers emerge.

Barrier one: Gathering high-quality data

Capturing a complete and accurate picture of emissions across the value chain is a major challenge. The lack of supplier-level data is the single biggest obstacle to measuring scope 3 emissions (as revealed by MIT’s 2025 State of the Supply Chain report). Many suppliers don’t track emissions, and reporting formats and methodologies vary widely.

Companies are falling back on secondary data, such as estimates, spend-based calculations and industry averages. While these approaches enable baseline reporting, they can reduce accuracy and limit confidence in the decisions underpinning a climate roadmap and ultimately, its ability to be delivered. Without reliable emissions data provided directly by suppliers, even the most motivated companies struggle to calculate accurate emissions, pinpoint true emission hotspots and generate real actionable insights that drive wider value for the business.

Barrier two: Engaging SME suppliers

Engaging suppliers is essential for improving Scope 3 emissions measurement and reporting. This isn’t an easy task, especially when it comes to SMEs. Many SMEs lack the knowledge, tools, time and resources to capture emissions data or build internal capability.

For ESG and sustainability teams, this creates a disproportionate challenge. While individual SMEs may contribute a relatively small proportion of scope 3 emissions, collectively they represent a significant share. Manually engaging large numbers of suppliers requires sustained effort and investment, and even then, response rates and data completeness often remain low when requests are complex or poorly aligned to supplier capability.

Barrier three: Incentivising behaviour change

Emission data collection is only the first step in meeting scope 3 targets. Delivering on climate roadmaps and achieving science-based targets requires actively incentivising change among suppliers. For SMEs, the challenge is not about intent, but instead often about feasibility. They want to act but often lack knowledge, capacity and clear guidance.

Buyer support is critical. Without engagement, guidance and incentives from larger organisations, real scope 3 emissions reductions remain a distant goal. Providing coaching and practical guidance can support suppliers, especially SMEs, to understand steps for lasting impact and to benefit from those actions. Our data shows that energy, waste and water switching can deliver savings of around £600 per business. Suppliers also gain access to their own emissions data, enabling them to track and share their climate progress to customers and other stakeholders.

Technology can unlock a practical way forward

Our work with supply chain owners and smaller organisations shows that consultants are often unaffordable and its digital solutions that can tackle these scope 3 barriers. The best solutions are designed for both buyers and SME suppliers. They enable high-quality data collection and meaningful action at scale, without adding unnecessary burden. These solutions combine:

Automated and standardised data: Streamlined scope 3 data collection with outputs aligned to the GHG Protocol and SBTi ensures reliable, comparable and audit-ready reporting in hours not days. Teams can capture 50% of total emissions in just a few clicks.

Data-driven insights: Dashboards help teams quickly identify hotspots, prioritise supplier support and focus action where it matters most.

Ease of SME participation: Simple requests, plain-language questions, and minimal inputs make it easy for suppliers to respond, while on-the-ground coaching builds capability and practical understanding.

Efficient, centralised engagement: Automation reduces manual effort for buyers managing large supplier bases. For companies engaging around 50 suppliers, this can save roughly eight weeks of effort.

For many companies, SBTs will be achieved, or missed, in the long tail of SME suppliers. By enabling data sharing, capability building and behaviour change across the supply chain, companies can make credible progress toward their climate targets while supporting suppliers on their own sustainability journeys.

Explore how organisations are engaging SME suppliers to improve Scope 3 data quality and advance science-based targets.