For most organisations, Scope 1 (direct) and Scope 2 (purchased energy) emissions represent only 10–20% of their total carbon footprint. The remaining 80–90% sits in Scope 3 — the value chain emissions that are hardest to measure and easiest to ignore.
Scope 3 encompasses 15 categories defined by the GHG Protocol, from purchased goods and services to end-of-life treatment of sold products. For a manufacturing company, raw material extraction and transportation often dwarf factory-floor emissions. For a financial institution, financed emissions are the dominant category.
The challenge is data. Unlike Scope 1 and 2, where metering and utility bills provide reliable figures, Scope 3 relies on supplier engagement, spend-based estimates, and life-cycle databases. The result is often a range rather than a precise number.
But imprecision is not an excuse for inaction. Regulatory pressure is mounting — the EU’s Corporate Sustainability Reporting Directive (CSRD) and India’s BRSR Core both push for value chain disclosure. Investors increasingly view Scope 3 as a proxy for strategic risk exposure.
RSustain’s approach to Scope 3 starts with materiality: identify the three or four categories that dominate your footprint, build supplier engagement programmes for primary data, and use recognised emission factors for the rest. Perfection is the enemy of progress.