California's SB 253 requires companies with over $1 billion in revenue to disclose Scope 1, 2, and 3 emissions with third-party assurance. This shifts carbon accounting from a voluntary sustainability exercise to a mandatory financial-grade requirement, putting the burden of data accuracy on the CFO. Capturing Scope 3 emissions remains the biggest hurdle, as these indirect supply chain emissions often make up the bulk of a corporate footprint. Companies must now move away from sporadic spreadsheets toward auditable data infrastructure to avoid legal and reputational risks.
