Tackling Scope 3 Emissions: Why Supplier Carbon Scores Are Essential

McKinsey estimates that Scope 3 emissions typically represent around 90 percent of a company’s total emissions. Despite this, many companies struggle to accurately measure and manage these emissions due to a lack of reliable supplier data.

As regulatory frameworks like the Corporate Sustainability Reporting Directive (CSRD) and European Sustainability Reporting Standards (ESRS E1) increase transparency requirements, organizations must go beyond estimations and adopt supplier-specific carbon scoring to reduce Scope 3 exposure and ensure compliance.

Measuring and reducing Scope 3 emissions is a big challenge for companies wanting to protect the climate. Unlike direct emissions (Scope 1) and emissions from purchased energy (Scope 2), Scope 3 includes all indirect emissions from a company's value chain. This is a broad area, so it's important to understand where these emissions come from, especially from suppliers. General data is often not precise enough for good insights and reduction plans. Getting specific data from suppliers is therefore key for businesses aiming for real Scope 3 reductions.

To know what data to measure from suppliers, a company needs to carefully look at its value chain and the activities that produce the most emissions. This means sorting and prioritizing different Scope 3 emission sources, such as purchased goods and services, equipment, energy-related activities not in Scope 1 or 2, transport of goods to the company, waste, business trips, employee commutes, rented buildings used by the company, transport of sold products, processing of sold products, use of sold products, disposal of sold products, rented buildings owned by the company but used by others, and franchises.

Once the most important Scope 3 categories are found, the specific data needed from suppliers can be defined. For example, for "Purchased Goods and Services," important supplier data could be:

• Origin of raw materials and how they are processed: Knowing where materials come from and how energy-intensive their production is can show major emission sources. Suppliers should provide data on the specific materials, their origin, and the energy used and efficiency of their production.
• Energy used in manufacturing: Detailed data on electricity and fuel used to produce goods and services, including renewable and non-renewable sources, is important for calculating emissions.
• Transportation data: Information on how goods are transported, distances, and fuel efficiency helps understand transport emissions in the supply chain.
• Waste and waste management: Data on the types and amounts of waste from production and how it's disposed of or recycled helps quantify the environmental impact of waste.
• Carbon footprint data per product: More and more, suppliers are expected to provide carbon footprint data for their products or services, which allows for more accurate allocation of emissions.

Similarly, for other relevant Scope 3 categories, specific data from suppliers is needed. For equipment, this could include the carbon footprint of the machinery. For downstream transport, it would involve data on the transport of finished products.

Collecting this detailed supplier data can be done in different ways, such as with questionnaires, data platforms, and systems for managing suppliers. Good relationships and clear communication with suppliers are very important for getting accurate information on time. Providing suppliers with clear guidelines, templates, and support can make data collection easier.

• Get a more accurate picture of their total carbon footprint: Moving beyond estimates gives a true view of emission sources in the value chain.
• Find key areas for reducing emissions: Detailed data shows where the biggest opportunities for improvement are.
• Work better with suppliers on sustainability: Sharing specific emission data can encourage cooperation and joint efforts to reduce environmental impact.
• Track progress and measure the success of reduction plans: Regular data collection helps monitor the impact of sustainability efforts and make necessary changes.
• Meet growing requirements from regulations and stakeholders: More pressure from governments, investors, and customers requires clear reporting of Scope 3 emissions.

Even though it's a challenge, measuring specific Scope 3 data from suppliers is essential for companies that seriously want to tackle their entire carbon footprint. By focusing on getting detailed and accurate information from their partners in the value chain, businesses can gain valuable insights, achieve significant emission reductions, and contribute to a more sustainable future.

• Supplier Emissions Intensity: CO2 emissions per unit of product or service provided.
• Verification or Audit Status: Whether supplier emissions data is verified by third parties.
• Scope 3 Tier Classification: Categorization of supplier impact based on position in the supply chain and emissions relevance.

These metrics form the foundation for credible Scope 3 accounting and drive informed sourcing decisions.

Common roadblocks for companies include:

• Low Transparency Across Supply Chains: Suppliers, especially in lower tiers, often lack emissions tracking capabilities.
• Manual Supplier Outreach and Data Collection: Relying on surveys and emails creates inefficiencies and data inconsistencies.
• Estimation-Based Modelling: Generic emissions factors do not reflect supplier-specific realities, increasing compliance risks.

According to a CDP Global Supply Chain Report, only 37% of suppliers currently engage in Scope 3 emissions tracking, highlighting the data gap companies must bridge.

Implementing supplier carbon scores offers multiple benefits:

• Supports Low-Carbon Sourcing – Enables procurement teams to prioritize suppliers with lower carbon intensity.
• Reduces Scope 3 Emissions Exposure – Identifies high-impact suppliers for targeted emissions reduction efforts.
• Improves ESG Ratings and Investor Confidence – Demonstrates proactive supply chain management and transparency.

With growing emphasis on supply chain emissions, supplier carbon scores are becoming a competitive differentiator in procurement and ESG strategies.

Carbmee’s Custom Properties allow companies to capture detailed supplier emissions data without altering core systems. Examples include:

• Supplier Carbon Score: Quantifies supplier emissions intensity and integrates it into the emissions model.
• Verification Level: Tracks data assurance status for each supplier.
• Scope 3 Tier Assignment: Classifies suppliers based on emissions relevance and supply chain position.

These custom fields feed into a centralized carbon model, enabling real-time Scope 3 tracking and supplier performance benchmarking.

Carbmee’s Carbontology framework links supplier entities to products, materials, and processes within your emissions model. This ensures:

• Supplier carbon data flows automatically to product-level Scope 3 footprints.
• Changes in supplier performance dynamically update emissions calculations.
• Compliance reports reflect live, accurate supply chain data.

This level of connectivity transforms Scope 3 management from manual estimation to real-time carbon intelligence.

To implement effective supplier carbon scoring:

1. Map Key Suppliers: Identify high-impact suppliers across your value chain.
2. Define Custom Properties: Establish fields for carbon scores, verification levels, and tier classifications.
3. Integrate Supplier Data: Collect and connect verified supplier emissions data.
4. Automate Reporting: Use dashboards to track Scope 3 emissions and supplier performance.

Book a demo with Carbmee to see how supplier carbon scores can transform your Scope 3 strategy.

For benchmarks and insights on Scope 3 supplier transparency, download the Sustainability Intelligence Report 2025.

Supplier carbon scores are essential for accurate Scope 3 accounting, regulatory compliance, and strategic emissions reduction. With Carbmee’s Custom Properties and Carbontology, companies can:

• Achieve supplier-specific Scope 3 visibility.
• Improve sourcing decisions based on carbon impact.
• Automate compliance with CSRD and ESRS requirements.

Move beyond estimations and gain actionable insights into your supply chain’s carbon footprint. Carbmee is ready to help.