What is sustainability reporting? The frameworks, and who must comply

Sustainability reporting is a company’s structured public disclosure of its environmental, social and governance performance. For twenty years it was a voluntary reputational exercise; in Europe it is now moving under the same regime as financial reporting — same report, same management responsibility, independent assurance.

The main frameworks

• GRI — the oldest and most widespread voluntary framework; broad stakeholder audience, impact-oriented
• CSRD / ESRS — Europe’s mandatory regime, covering companies above size thresholds; climate sits in ESRS E1
• ISSB (IFRS S1/S2) — an investor-focused global standard set built on financial materiality
• CDP — a questionnaire-based disclosure system filled in at investor and buyer request
• TCFD — a framework for financial disclosure of climate risk, largely absorbed by ISSB

Materiality: two different meanings

This is the most fundamental difference between frameworks. ISSB looks at financial materiality: does this topic affect the company’s value? CSRD requires double materiality: a topic is reported if it affects the company’s value or if the company has a significant impact on it. The second condition widens scope considerably.

You are affected even when out of scope

CSRD directly covers only large companies. But their Scope 3 data comes from suppliers. A Turkish producer selling to a European customer faces product-level emissions data requests because of the customer’s obligation, even if they are not in scope themselves.

The request arrives not as a questionnaire but as a field in a supplier portal: kg CO₂e per product, verification status, data source. A supplier who cannot fill it is represented by a sector average in the customer’s report — and the average is almost always worse than actual performance.

How product data feeds the report

A corporate report is annual and company-wide; LCA is per product. The link is made at two points: the footprints of materials you buy feed Scope 3 Category 1; the use and end-of-life impact of products you sell feed Categories 11 and 12. Two cuts through the same data pool.

Assurance: the report’s hidden cost

Under mandatory regimes the report is subject to independent assurance — the data path behind the figures is audited. That requires sustainability data to be managed like financial data: source documents, calculation steps, approval records, versioning. A dataset assembled in spreadsheets at year-end does not pass.