ISSB Launches Nature Disclosure Consultation as California's Climate Deadline Looms

ISSB Proposes First Nature-Related Disclosure Practice Statement

On October 22, 2026, the International Sustainability Standards Board (ISSB) published an exposure draft of IFRS Sustainability Disclosure Practice Statement 1 — Nature-related Disclosures, opening a 120-day public comment window that closes on February 19, 2027. The move, confirmed by PwC, IAS Plus, ESG Today, and the IFRS Foundation itself, marks the ISSB's most significant step yet toward formalizing how companies should report their dependencies and impacts on biodiversity, water, and other natural systems.

What the Exposure Draft Proposes

According to PwC's In Brief published the same day, the draft proposes disclosure requirements for nature-related risks and opportunities that could affect an entity's cash flows, access to finance, or cost of capital. Critically, the proposal takes the form of a Practice Statement rather than a standalone standard — meaning, as GRC Report noted, companies would not need to follow it to claim compliance with existing ISSB standards. However, IFRS S1 already requires disclosure of material sustainability-related risks, which in practice creates a de facto expectation for companies to engage with nature-related information if it is material.

The draft draws heavily on the Taskforce on Nature-related Financial Disclosures (TNFD) framework. As Winn Solutions observed, the October 2026 exposure draft effectively marks the ISSB's formal absorption of the TNFD's work into its own standard-setting process. The ISSB timed the consultation launch to coincide with COP17 — the UN Convention on Biological Diversity — hosting a live webinar on the day of publication.

Where This Sits in the Broader ISSB Architecture

The proposed Practice Statement is designed to complement, not alter, the existing IFRS S1 and IFRS S2 (Climate-related Disclosures) standards. The ISSB's deliberate choice of the Practice Statement vehicle reflects a balancing act: improving comparability of nature-related information without adding mandatory requirements that could slow adoption of its core climate standards in jurisdictions still building regulatory infrastructure.

California's SB 253 Deadline: Fifteen Days Away

Simultaneously, U.S.-based companies are facing an imminent domestic milestone. On October 12, 2026, the California Office of Administrative Law approved the California Air Resources Board's (CARB) initial regulation implementing SB 253 and SB 261, effective immediately, as confirmed by Thompson Hine, Akin Gump, and Simpson Thacher in separate client alerts. The regulation formalizes November 10, 2026 as the first-ever deadline for Scope 1 and Scope 2 greenhouse gas emissions reporting under SB 253. SB 253 applies to U.S.-organized businesses with more than $1 billion in annual revenue that do business in California, per Thompson Hine's analysis.

First-year relief is codified: companies may rely on emissions data they already had or were collecting by December 5, 2024, or may file a statement of non-reporting on company letterhead. Scope 3 reporting is not required until 2027. Notably, SB 261 — the companion law requiring biennial climate-related financial risk disclosures — remains on hold pending a Ninth Circuit appeal, according to Proskauer Rose.

The Regulatory Divergence Is Sharpening

Taken together, this week's developments illustrate a widening split in the global disclosure landscape. The ISSB is extending its framework outward from climate toward nature, building on IFRS S2's architecture. The EU's revised ESRS, published in the Official Journal on September 21 and entering into force on November 10, 2026, applies to financial years beginning January 1, 2027. Meanwhile, at the U.S. federal level, the SEC has proposed rescinding its 2024 climate disclosure rules entirely — leaving sub-national rules like California's as the primary mandatory climate reporting regime for many American companies.