Measuring and Reporting Scope 3 Emissions Effectively

A sustainability manager at a global food company once told me, “We thought we were doing everything right—switching to renewable energy, cutting waste, optimizing transport routes. But when we finally measured our Scope 3 emissions, we realised they were over five times larger than our operational emissions. It was like discovering an iceberg beneath the surface.”

This experience is not unique. Many companies focus on reducing their direct (Scope 1) emissions and cleaning up their purchased electricity (Scope 2), only to later realise that the majority of their carbon footprint sits elsewhere—hidden within their supply chains, transportation, product use, and disposal. Scope 3 emissions, which often account for more than 70% of a company’s total carbon footprint (source), are by far the hardest to measure and manage. But as pressure mounts from regulators, investors, and consumers, businesses can no longer afford to ignore them.

The challenge with Scope 3 isn’t just about size—it’s about complexity. These emissions stretch across vast global supply chains, where data is often incomplete, inconsistent, or simply unavailable. Unlike Scope 1 and 2, where companies have direct control, Scope 3 requires gathering information from external partners, many of whom may not even track their own emissions. Yet, despite these hurdles, companies that embrace a structured approach to measuring Scope 3 can unlock opportunities for efficiency, cost savings, and long-term sustainability.

An organization can take several approaches to measuring Scope 3 emissions, including spend-based, activity-based, supplier-based or a hybrid method. When assessing emissions at the product level, Life Cycle Assessment (LCA) is one of the most effective tools.

LCA provides a detailed view of emissions across a product’s entire journey—from raw material extraction to disposal. For instance, a frozen food manufacturer that conducted an LCA found that its biggest emissions hotspot wasn’t packaging or transportation, as it had assumed, but raw material sourcing. By switching to more sustainable ingredients, the company reduced its overall footprint and strengthened its sustainability credentials. Beyond LCA, carbon footprinting tools, supplier engagement programs, and emissions modelling techniques can help companies collect and refine their data, even when direct measurement isn’t possible.

That said, measuring Scope 3 is only part of the equation. Many companies struggle with data consistency and standardization, as suppliers use different methodologies or lack the resources to track emissions at all. Others face consumer skepticism, as accusations of greenwashing make stakeholders wary of carbon claims. To overcome these challenges, businesses should follow globally recognized standards like the GHG Protocol and ISO 14064, set clear data collection frameworks, and engage suppliers as early as possible.

Transparency is also key — companies that communicate their findings clearly, disclose assumptions, and avoid overclaiming will build far more trust than those that publish vague sustainability statements. Verification of Scope 3 emissions is also essential for ensuring accurate and reliable data, which builds trust with stakeholders. It helps companies identify major sources of greenhouse gas emissions in their value chain, enabling effective reduction strategies. Verified data also supports compliance with environmental regulations and enhances a company’s sustainability reputation, contributing to global climate goals.

Measuring Scope 3 emissions may feel overwhelming, but it’s also an opportunity. Companies that proactively tackle these emissions can not only reduce their climate impact but also future-proof their supply chains, mitigate business risks, and strengthen their market position. The key is to start somewhere — whether it’s engaging suppliers, running an LCA, or setting up better reporting mechanisms. Because as that sustainability manager learned, the real challenge isn’t just in finding the iceberg. It’s in figuring out how to chip away at it.

Vishal Gangwar is Senior Sustainability Assessor SEA, DNV