What Are Scope 3 Emissions and Why Do They Matter?

Scope 3 emissions can represent up to 75% of a company's total carbon footprint. Yet, measuring them is one of the biggest challenges in carbon accounting. As regulations like the Corporate Sustainability Reporting Directive (CSRD) enforce transparency, businesses must adopt robust strategies to reduce their environmental impact. This article explores what Scope 3 emissions are, why they matter, the challenges they present, and how advanced tools like GEMS can simplify the measurement process.

What are Scope 3 emissions and why do they matter?

Carbon accounting basics

Greenhouse Gas (GHG) emissions are classified into three scopes as defined by frameworks like the GHG Protocol.

• Scope 1: Direct emissions from sources owned or controlled by a company (e.g., fuel combustion on-site).
• Scope 2: Indirect emissions from the consumption of purchased electricity, steam, heating, or cooling.
• Scope 3: All other indirect emissions occurring across a company’s value chain.

For many businesses, Scope 3 emissions constitute the majority of their carbon footprint, encompassing activities such as upstream manufacturing, downstream product use, employee commuting, and waste management.

The importance of scope 3 emissions for companies

Measuring Scope 3 emissions is essential to understanding the full environmental impact of a business:

• Comprehensive View: It provides a holistic view of a company’s carbon footprint.
• Risk Assessment: Identifying supply chain dependencies and vulnerabilities.
• Regulatory Compliance: Mandatory in many jurisdictions, including under the CSRD and France’s updated GHG reporting rules.

Increasingly, the inclusion of Scope 3 emissions in reporting is no longer optional. It is now mandatory under regulations such as the CSRD in the EU and national decrees like France’s updated greenhouse gas reporting requirements.

Challenges in Measuring Scope 3 Emissions

Common obstacles for measuring Scope 3 emissions

Measuring Scope 3 emissions is inherently complex due to its broad scope. Companies often face several challenges:

• Data Gaps and Inconsistencies: Collecting activity data across an extended value chain can be daunting, especially when relying on supplier estimates or outdated emission factors.
• Unclear Boundaries: Determining which activities to include often requires significant interpretation and can lead to either overestimations or omissions.
• Over-reliance on Monetary Data: Using financial records to estimate emissions sacrifices granularity and accuracy.
• Double Counting: When multiple departments or stakeholders report overlapping data, discrepancies arise.
• Stakeholder Engagement: Involving multiple parties across the value chain can delay data collection and lead to inconsistent reporting.

Efficient measurement strategies to measure Scope 3 emissions

To overcome these hurdles, businesses should:

• Define clear objectives for carbon accounting, such as compliance, certification, or transition planning.
• Prioritize emission sources based on their materiality, using sectoral studies and peer benchmarks.
• Establish centralized data collection processes to prevent redundancy and ensure consistency.
• Use a phased approach, focusing on major emission sources initially while setting improvement goals for subsequent years.

Our Consulting Service and our Software: A Complete Solution to Simplify Scope 3 Emissions Measurement

Measuring Scope 3 emissions remains one of the biggest challenges for companies committed to climate action. Data gaps, supply chain complexity, and diverse sources make the process particularly difficult. That’s why we’ve developed a combined approach, leveraging the expertise of our consultants and the power of our GEMS software, to offer a solution that is complete, reliable, and adaptable.

Our consultants, a real added value to measure your scope 3 emissions

Our consultants, experts in decarbonization, play a key role in the success of your carbon accounting journey. We help:

• Structure and scope the Scope 3 data collection process, identifying key emission sources and high-impact areas.

• Prioritize data collection efforts, focusing on the most material emissions based on your sector and value chain.

• Ensure data quality and reliability, through rigorous review and expert guidance.

• Build a realistic climate roadmap, including a tailored transition plan aligned with your decarbonization targets.

What sets our consulting offering apart:

• A team trained in leading carbon accounting methodologies (ADEME’s Bilan Carbone®, GHG Protocol, PCAF).

• A dedicated consultant who oversees your project from A to Z, ensuring continuity and deep understanding of your specific challenges.

• A fully customizable approach, covering training, scoping, data collection, analysis, and validation, adapted to your goals and constraints.

GEMS: Our Software to Structure and Streamline Scope 3 Measurement

In addition to consulting, our GEMS software automates and simplifies the entire Scope 3 emissions measurement process:

A large emission factor database

GEMS draws from a wide range of reputable emission factor databases such as EcoInvent, CDP, IEA, and sector-specific sources like Agribalyse and Boavizta to ensure accurate carbon footprint assessments. It also integrates supplier-specific and regionalized data, enabling precise calculations aligned with global standards like the GHG Protocol.

Guided data collection

GEMS uses intuitive decision trees to walk users through the data collection process. When data is missing, smart alternative questions help estimate emissions with greater accuracy. GEMS also supports bulk data import through customizable Excel templates, reducing manual input and improving efficiency.

Visualisation and audit-ready reports

GEMS provides dynamic dashboards, automated data exports, and audit-ready reports fully aligned with international reporting standards such as the GHG Protocol and the CSRD.

Thanks to the synergy between our consulting service and technologically advanced software, we provide a comprehensive framework that allows you to:

• Strengthen the credibility of your carbon reporting

• Meet evolving regulatory requirements

• Develop actionable, science-aligned climate strategies to support your Net Zero objectives

Conclusion:

Scope 3 emissions are a cornerstone of any serious carbon accounting strategy, as they reflect a company’s overall environmental impact, far beyond its direct operations. These emissions span the entire value chain, from suppliers and logistics to product use and end-of-life, and are often the hardest to measure.

However, tackling Scope 3 emissions comes with significant challenges: fragmented data, reliance on third parties, and methodological uncertainties. That’s why combining a robust platform like GEMS with the support of ClimateSeed’s expert consultants is a powerful response. This integrated approach simplifies data collection, enhances reliability, and enables the generation of accurate, actionable, and compliant reports.

By adopting a solid Scope 3 strategy, companies can build trust, anticipate stakeholder and regulatory expectations, and lay the foundation for ambitious decarbonization aligned with Net Zero targets.