Introduction: The Largest Share of Emissions That Companies Know the Least About
Over the past few years, greenhouse gas accounting has become one of the most important aspects of corporate sustainability. Organisations across the world are measuring emissions, announcing net zero commitments, setting reduction targets and communicating their climate strategies to investors, customers, regulators and other stakeholders. In India, this momentum has also accelerated with increasing focus on Business Responsibility and Sustainability Reporting (BRSR), climate related disclosures and growing expectations from global customers and financial institutions.
As companies begin their decarbonisation journey, most are reasonably comfortable measuring emissions that arise directly from their own operations or from the electricity they purchase. These are commonly referred to as Scope 1 and Scope 2 emissions. While these categories certainly require technical expertise, the required information generally remains within the organisation’s operational control.
The situation changes significantly when organisations attempt to measure Scope 3 emissions.
For many businesses, Scope 3 represents the largest contributor to their overall carbon footprint. In several sectors, it accounts for more than seventy percent of total emissions, while in others it may exceed ninety percent depending upon the nature of operations and the complexity of the value chain. Ironically, despite being the largest component of an organisation’s greenhouse gas inventory, Scope 3 is also the least understood, the least consistent and often the least reliable aspect of ESG reporting.
The challenge is not simply about performing calculations. It is about understanding an organisation’s value chain, engaging with suppliers and customers, interpreting international guidance correctly, collecting reliable data and developing methodologies that produce meaningful results. Many companies discover that measuring Scope 3 is not merely an environmental exercise. It requires collaboration across procurement, finance, operations, logistics, product development and sustainability functions.
Understanding this distinction is critical because organisations that underestimate the complexity of Scope 3 often produce disclosures that appear complete on paper but provide limited insight into their actual climate impact.
Understanding Scope 3 Beyond the Definition
Scope 3 emissions are generally described as indirect greenhouse gas emissions that occur across an organisation’s value chain but are not owned or directly controlled by the reporting company.
Although this definition is technically correct, it does not adequately explain why Scope 3 is fundamentally different from other emission categories.
Unlike Scope 1 and Scope 2, where organisations have direct access to operational information, Scope 3 requires businesses to understand activities taking place outside their organisational boundaries. These activities may involve suppliers, transport partners, contractors, distributors, customers, waste handlers, franchisees, leased assets, or investments depending upon the nature of the business.
The internationally recognised Greenhouse Gas Protocol identifies fifteen categories of Scope 3 emissions. However, not every category is applicable to every organisation. Determining applicability itself requires a careful assessment of business operations, supply chain structure, procurement practices, product life cycle and materiality.
This is where many organisations make their first mistake. Instead of evaluating each category systematically, they either attempt to report all categories without sufficient justification or ignore categories that may actually represent significant emission sources.
An effective Scope 3 assessment therefore begins with understanding the business itself before attempting to quantify emissions.
Why Scope 3 Has Become Increasingly Important
The importance of Scope 3 has increased because businesses are now expected to demonstrate climate performance beyond the boundaries of their own facilities.
Investors increasingly recognise that a company’s exposure to climate risk extends beyond its manufacturing plants or offices. Customers want greater transparency regarding the environmental footprint of products they purchase. Multinational corporations are requesting emissions information from suppliers as part of procurement and supplier evaluation processes. Financial institutions are incorporating climate considerations into lending and investment decisions.
Consequently, companies are expected to understand how their purchasing decisions, transportation practices, product design, supplier relationships and downstream activities contribute to greenhouse gas emissions.
This shift reflects a broader understanding that climate impact cannot be assessed solely by examining direct operations. A manufacturing company may successfully reduce emissions within its own facilities, but if its suppliers continue operating inefficient processes or if its products consume significant energy throughout their useful life, the overall environmental impact remains substantial.
Scope 3 therefore provides a more complete picture of an organisation’s climate footprint and highlights opportunities for meaningful reductions across the value chain.
Why Indian Companies Continue to Face Significant Challenges
Although awareness regarding Scope 3 has increased considerably, implementation remains difficult for many Indian organisations.
One of the primary reasons is the structure of Indian supply chains.
Many industries depend upon extensive networks of small and medium enterprises. These suppliers often possess strong technical capabilities within their respective sectors but may have limited exposure to greenhouse gas accounting, ESG reporting, or sustainability data management. Expecting every supplier to maintain comprehensive emissions inventories is often unrealistic.
This creates a practical challenge for reporting organisations. Even where suppliers are willing to cooperate, they may not possess the information necessary to provide reliable emissions data.
Another challenge arises from procurement practices.
Historically, supplier selection has largely focused on quality, cost, delivery schedules and technical capability. Environmental data has rarely formed part of routine procurement discussions. Introducing carbon reporting therefore requires organisations to establish entirely new communication channels, data collection mechanisms, contractual expectations and supplier engagement programmes.
The challenge is organisational as much as technical.
Procurement teams, sustainability professionals, operations personnel, logistics managers and finance departments must begin working together in ways that many organisations have never previously experienced.
Estimation Versus Primary Data
One of the most debated aspects of Scope 3 reporting concerns the use of estimated data.
It is important to recognise that the use of estimates is not inherently incorrect. International methodologies acknowledge that obtaining primary data from every supplier or value chain partner may not always be feasible, particularly during the initial stages of reporting.
Accordingly, organisations often rely on secondary data sources, industry average emission factors, spend based calculations, or activity-based estimates where primary information is unavailable.
However, difficulties arise when estimated data continues to be used indefinitely without any long-term strategy for improving data quality.
Good Scope 3 reporting should demonstrate progression.
Initially, estimates may be necessary.
Over time, organisations should gradually replace estimates with supplier specific information wherever practical. This improves accuracy, strengthens stakeholder confidence and enables more meaningful emission reduction strategies.
The objective should never be to achieve mathematical perfection immediately. Rather, it should be to develop a structured roadmap that improves data quality year after year.
Common Mistakes That Organisations Make
Experience across industries indicates that many Scope 3 reporting challenges arise not because of technical limitations but because of planning deficiencies.
Some organisations begin collecting data without first determining which Scope 3 categories are material.
Others calculate emissions without documenting methodologies, making future reporting inconsistent.
Some rely entirely on consultants without building internal understanding, resulting in repeated dependence each reporting cycle.
Another common issue involves treating Scope 3 as a year-end reporting exercise rather than an ongoing management process. Supplier engagement, contractual expectations, internal governance and data validation require continuous attention throughout the reporting period.
Organisations also tend to underestimate the importance of documenting assumptions, boundaries, exclusions, emission factors and calculation methodologies. Without such documentation, maintaining consistency across reporting years becomes increasingly difficult.
Looking Beyond Compliance
There is a tendency to view Scope 3 solely through the lens of regulatory reporting.
Such an approach limits its value.
A well-developed Scope 3 inventory provides management with insights that extend far beyond disclosure requirements. It helps identify carbon intensive procurement categories, evaluate supplier performance, improve logistics efficiency, support sustainable product development, strengthen climate related decision making and prepare organisations for future stakeholder expectations.
In many respects, Scope 3 should be viewed as a business intelligence exercise rather than merely a reporting requirement.
The organisations deriving the greatest value from greenhouse gas accounting are those integrating emissions information into operational and strategic decisions instead of limiting it to annual sustainability reports.
Building a Practical Roadmap
Developing a credible Scope 3 inventory requires a phased approach.
Organisations should first understand their business model and identify applicable categories. Material categories should then be prioritised based on significance and availability of information.
Supplier engagement should gradually become part of procurement processes rather than an isolated sustainability initiative. Internal governance structures should clearly define responsibilities for data collection, validation, review and continuous improvement.
Equally important is the development of consistent calculation methodologies and documentation practices. Transparent reporting of assumptions, limitations and data sources enhances credibility and allows stakeholders to understand the maturity of the reporting process.
Scope 3 should therefore evolve alongside the organisation’s ESG journey. Perfection should not be the initial objective. Continuous improvement should.
How ESG360 Supports Organisations
At ESG360, we recognise that Scope 3 reporting is far more than an emissions calculation exercise. It requires an understanding of business operations, supply chain dynamics, international methodologies and practical implementation challenges.
Our approach begins with evaluating the organisation’s business model to determine applicable Scope 3 categories and identify material emission sources. We support organisations in designing structured data collection frameworks, engaging suppliers, selecting appropriate calculation methodologies, documenting assumptions and developing robust greenhouse gas inventories aligned with recognised standards.
Beyond calculations, we help organisations strengthen governance processes around emissions management so that Scope 3 reporting becomes progressively more accurate, transparent and decision useful over successive reporting cycles.
Our objective is not merely to prepare an inventory for a reporting year but to help organisations establish systems capable of supporting long term climate strategies.
Conclusion
Scope 3 is often described as the most difficult component of greenhouse gas accounting. While this observation is accurate, it should not discourage organisations from beginning the journey.
The complexity of Scope 3 reflects the complexity of modern business itself. Supply chains have become increasingly interconnected, products move across multiple geographies, and business relationships extend far beyond organisational boundaries. Measuring emissions across this ecosystem inevitably requires greater collaboration, stronger governance and continuous improvement.
The organisations that approach Scope 3 with patience, structure and a commitment to improving data quality over time will be better positioned to respond to evolving stakeholder expectations, strengthen climate strategies and build more resilient value chains.
Ultimately, Scope 3 should not be viewed as the most difficult part of ESG reporting. It should be recognised as the opportunity that enables organisations to understand where their greatest environmental impact truly lies and where meaningful change can begin.