Climate disclosure is shifting from optional sustainability storytelling to mandatory, regulated reporting, and organisations need to take note.

California’s Climate Corporate Data Accountability Act (SB 253) requires large companies doing business in the state to publicly disclose their greenhouse gas emissions — including Scope 1, Scope 2, and Scope 3, aligned with recognised standards. This isn’t just about reporting direct emissions from owned operations; it extends into the value chain, making emissions from suppliers and end-use activities part of what must be measured and disclosed.

For many organisations, especially mid-market companies and multi-entity groups, this represents a significant challenge. Scope 3 emissions in particular are often the largest share of an organisation’s carbon footprint — yet they remain difficult to track, quantify, and defend with audit-level data.

As regulatory scrutiny increases and reporting requirements converge with assurance expectations, the limitations of spreadsheets and disconnected data systems become more apparent. Structured data, finance integration, and controlled workflows are rapidly becoming essential for credible climate reporting.

Bridging the Gap: ESG Reporting Platforms

This is where ESG reporting software like Taxilla comes into play. Platforms that unify ESG and financial data help organisations automate emissions tracking, standardise data collection, and produce audit-ready disclosures across multiple frameworks — from California’s SB 253 to international standards such as ISSB/IFRS, GRI, and TCFD.

By linking emissions data to financial systems, supplier networks, and procurement records, organisations can:

Capture Scope 1, 2, and 3 emissions reliably

Standardise methodologies and control calculations

Build traceable data lineages needed for assurance

Produce multi-framework reporting from a single dataset

In an era where climate reporting expectations are converging with financial reporting standards, the winners will be organisations that treat emissions data with the same rigour as their financials — supported by technology that scales with complexity.

California has changed the rules of climate reporting—and the impact goes far beyond sustainability teams.

With SB 253 and SB 261, climate disclosure is no longer voluntary or narrative-driven. For large U.S. companies doing business in California, emissions data and climate risk reporting are now regulated, auditable, and tied directly to financial governance.

SB 253 requires covered entities to disclose Scope 1, 2, and eventually Scope 3 emissions, while SB 261 focuses on climate-related financial risk, forcing organizations to assess and explain how climate impacts revenue, operations, and long-term resilience.

What’s different this time? Climate data is being treated like financial data—expected to be structured, consistent, evidence-backed, and defensible under regulatory scrutiny.

The ripple effects extend well beyond companies directly in scope. Suppliers, private firms, and portfolio companies are increasingly being asked for reliable emissions and climate-risk data to support compliance across value chains.

California’s message is clear: Climate risk is financial risk—and disclosure expectations have permanently shifted.

Organizations that prepare early, with finance-grade ESG and carbon data systems, will move faster, respond with confidence, and avoid last-minute compliance pressure.

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By Michael Cohn