Environmental Disclosure in US IPOs: Climate Risk and Sustainability Reporting Standards

The SEC’s final climate disclosure rules, adopted on 6 March 2024 under Release Nos. 33-11275 and 34-99678, have survived legal challenges and are now shaping the 2025-2026 IPO pipeline for issuers targeting the NYSE and NASDAQ. Although the SEC stayed implementation on 4 April 2024 pending the consolidated Eighth Circuit litigation, the rules are not dead — they are merely delayed, and the compliance trajectory for registrants filing F-1 or S-1 registration statements remains clear. For Hong Kong-based issuers and cross-border sponsors, the practical implication is that climate risk disclosure is no longer a voluntary ESG add-on but a mandatory line item in the prospectus risk factor section and MD&A. The SEC’s rule mandates disclosure of material Scope 1 and Scope 2 greenhouse gas (GHG) emissions for large accelerated filers, with Scope 3 subject to a phased-in materiality assessment. Simultaneously, the HKEX’s enhanced climate-related disclosures under Appendix 27 of the Main Board Listing Rules, effective from 1 January 2025, impose parallel obligations on Hong Kong-listed companies. For any issuer pursuing a dual-primary or secondary listing in both Hong Kong and the United States, the convergence of these two regulatory regimes creates both compliance burdens and strategic opportunities in the structuring of the offering.

The SEC Climate Disclosure Rule: Scope, Timelines, and Materiality Thresholds

The SEC’s final rule, titled “The Enhancement and Standardization of Climate-Related Disclosures for Investors,” represents the first mandatory federal climate disclosure regime in US capital markets history. The rule applies to all registrants filing registration statements under the Securities Act of 1933 and periodic reports under the Securities Exchange Act of 1934, including foreign private issuers (FPIs) using Form 20-F or F-1.

Scope 1 and Scope 2 Emissions: Mandatory for Large Accelerated Filers

For large accelerated filers (public float above USD 700 million), the rule requires disclosure of Scope 1 and Scope 2 GHG emissions — direct emissions from owned sources and indirect emissions from purchased energy — on a phased-in schedule. The first compliance date for these disclosures in annual reports for fiscal years beginning in 2026 (i.e., reports filed in 2027) remains the operative timeline, assuming the stay is lifted. For accelerated filers and non-accelerated filers, the timeline extends to fiscal years beginning in 2027 and 2028, respectively. Critically, the SEC retained the materiality qualifier: only emissions that are material to the registrant’s financial condition or operating performance must be disclosed. This is a narrower standard than the EU’s Corporate Sustainability Reporting Directive (CSRD), which mandates full double materiality without a de minimis exemption.

Scope 3 Emissions: Conditional and Phased-In

The SEC’s final rule removed the mandatory Scope 3 disclosure that appeared in the March 2022 proposal. Instead, Scope 3 emissions are required only when the registrant has set a public GHG emissions reduction target that includes Scope 3, or when Scope 3 is material to the registrant’s business. For FPIs, including Hong Kong-based groups with PRC operating entities, this means that if the issuer’s sustainability report or investor presentation references Scope 3 reduction goals — a common practice among large-cap Chinese tech and manufacturing companies — the SEC will require those figures to be audited or assured at the limited assurance level by FY2029. Sponsors should advise issuers to either remove Scope 3 targets from pre-IPO materials or budget for the assurance cost, which KPMG estimates at USD 150,000 to USD 500,000 per engagement depending on group complexity.

Risk Factor and MD&A Disclosure Requirements

Beyond emissions data, the rule mandates qualitative disclosures in the prospectus risk factors and Management’s Discussion and Analysis (MD&A) sections. Registrants must describe:

Material climate-related risks that have had or are reasonably likely to have a material impact on the business, including physical risks (e.g., extreme weather events, sea-level rise) and transition risks (e.g., regulatory changes, technology shifts).
The actual and potential financial impacts of these risks, quantified where practicable.
The registrant’s climate risk management processes and board oversight of climate-related issues.
Any climate-related targets or goals that materially affect the registrant’s business, including the methodology and assumptions used to measure progress.

For a Hong Kong-headquartered manufacturing group with factories in the Pearl River Delta or the Yangtze River Delta, the physical risk disclosure may need to reference typhoon frequency data from the Hong Kong Observatory or the China Meteorological Administration. Transition risk disclosure must address the potential impact of the PRC’s dual-carbon policy (peak carbon by 2030, carbon neutrality by 2060) on energy costs and regulatory compliance.

The HKEX Climate Disclosure Regime: Appendix 27 and the ISSB Alignment

Effective 1 January 2025, the HKEX introduced enhanced climate-related disclosures under Appendix 27 of the Main Board Listing Rules and Appendix 22 of the GEM Listing Rules. These rules align with the International Sustainability Standards Board (ISSB) IFRS S2, “Climate-related Disclosures,” and apply to all issuers on a comply-or-explain basis, with certain mandatory requirements for large-cap issuers.

Mandatory Disclosure of Scope 1, 2, and 3 Emissions for Hang Seng Index Constituents

Under paragraph 29 of Appendix 27, Hang Seng Index (HSI) constituent issuers must disclose Scope 1, 2, and 3 GHG emissions in their ESG reports for fiscal years commencing on or after 1 January 2025. The HKEX explicitly requires third-party assurance for Scope 1 and Scope 2 emissions for HSI constituents, with a phased-in timeline: limited assurance by FY2027 and reasonable assurance by FY2029. For non-HSI issuers, Scope 3 emissions disclosure is encouraged but not mandatory, though the HKEX has indicated it will review this position in 2026.

Climate Risk Scenario Analysis and Resilience Assessment

Paragraph 35 of Appendix 27 requires issuers to conduct climate risk scenario analysis, including both a 2°C or lower scenario and a higher-emissions scenario (e.g., 4°C). The analysis must cover physical risks (acute and chronic) and transition risks, and the issuer must disclose the resilience of its strategy to these scenarios. For a Hong Kong-listed real estate developer with mainland China projects, this means modelling the impact of a 1-in-100-year flood event on property valuations in coastal cities such as Shanghai or Shenzhen. The HKEX’s guidance note issued in April 2024 provides a detailed methodology, including recommended climate models from the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report.

Board Oversight and Management Accountability

Appendix 27 mandates that the board of directors take responsibility for climate-related disclosures, with at least one board-level committee (e.g., the audit committee or a dedicated ESG committee) overseeing climate risk management. The issuer must disclose the board’s climate-related expertise, the frequency of board-level climate risk reviews, and how management is compensated in relation to climate targets. This aligns with the SEC’s requirement for board oversight disclosure in the proxy statement or Form 20-F, creating a consistent narrative for dual-listed issuers.

Cross-Border Compliance: Navigating the SEC-HKEX Convergence

For a Hong Kong issuer pursuing a US IPO, the compliance challenge is not merely additive — it is multiplicative. The SEC and HKEX regimes differ in scope, materiality thresholds, and assurance requirements, but the underlying data collection and governance infrastructure is largely the same. A well-structured compliance programme can serve both regulators simultaneously.

Data Collection and Internal Controls

Both the SEC and HKEX require GHG emissions data across Scopes 1, 2, and 3, albeit with different materiality thresholds. The SEC applies a US GAAP materiality standard (ASC 250-10-20), while the HKEX follows a “comply-or-explain” model with an expectation of full disclosure for HSI constituents. For a Hong Kong issuer with subsidiaries in the PRC, BVI, Cayman Islands, and Bermuda, the operational challenge is aggregating emissions data from disparate legal entities with different reporting systems. The SEC’s Internal Control Over Financial Reporting (ICFR) requirements under Section 404 of the Sarbanes-Oxley Act (SOX) apply to accelerated filers and large accelerated filers, and the climate data must be subject to the same internal control framework. The Public Company Accounting Oversight Board (PCAOB) has indicated that it will inspect climate-related internal controls as part of its regular audit inspections, meaning that a material weakness in emissions data controls could trigger a SOX 404 adverse opinion.

Assurance Timelines and Auditor Qualification

The SEC’s phased-in assurance requirement for Scope 1 and Scope 2 emissions begins at limited assurance for FY2029 (for large accelerated filers) and moves to reasonable assurance for FY2033. The HKEX’s timeline is compressed: limited assurance for HSI constituents by FY2027 and reasonable assurance by FY2029. For a dual-listed issuer, the HKEX timeline is the binding constraint. The issuer must engage a qualified assurance provider — typically one of the Big Four (Deloitte, EY, KPMG, PwC) or a specialist ESG assurance firm — that is registered with both the PCAOB (for US purposes) and the Hong Kong Institute of Certified Public Accountants (HKICPA) (for HKEX purposes). The assurance engagement must cover the same data set, but the scope of work may differ: the SEC requires assurance over emissions data in the annual report, while the HKEX requires assurance over the ESG report published separately. The issuer should budget for two separate assurance engagements unless the audit committee can negotiate a combined engagement under the PCAOB’s interim assurance standards.

Prospectus Risk Factor Drafting for Dual-Listed Issuers

The prospectus risk factor section for a dual-listed issuer must address both regimes. Standard language for a Hong Kong-US dual listing might read: “The Company is subject to climate-related disclosure requirements under both the SEC’s final rule (Release No. 33-11275) and the HKEX’s Appendix 27 of the Main Board Listing Rules. Any failure to comply with these requirements, including the timely disclosure of Scope 1, Scope 2, and Scope 3 GHG emissions, could result in SEC enforcement actions, HKEX disciplinary proceedings, or shareholder litigation under Section 10(b) of the Securities Exchange Act of 1934 or Section 384 of the Securities and Futures Ordinance (Cap. 571).” This language must be tailored to the issuer’s specific risk profile, including the materiality of climate risks to its business model.

The integration of climate disclosure into the IPO process affects three critical phases: pre-filing due diligence, SEC comment letter response, and post-IPO compliance.

Pre-Filing Due Diligence: The Climate Data Room

Sponsors and legal counsel should establish a climate data room as part of the standard due diligence process, alongside the traditional financial, legal, and tax data rooms. The data room should contain:

GHG emissions inventories for the past three fiscal years, broken down by legal entity and geography.
Climate risk assessments, including scenario analysis outputs.
Board and management committee charters demonstrating climate oversight.
Any public climate targets or commitments, with supporting methodology documentation.
Assurance reports (if any) from prior years.

The due diligence should also include a review of the issuer’s internal controls over climate data, following the COSO 2013 framework. Any gaps in controls should be remediated before the F-1 filing, as the SEC staff has indicated that climate-related control deficiencies will be a focus area in comment letters.

SEC Comment Letter Process: Climate Disclosure as a Recurring Topic

Based on a review of SEC comment letters issued to FPIs in 2024-2025 (available on the SEC’s EDGAR system), the Division of Corporation Finance is increasingly requesting:

Clarification of the materiality assessment for Scope 3 emissions.
Reconciliation of climate risk disclosures with the issuer’s financial statements, particularly with respect to impairment charges, asset retirement obligations, and contingent liabilities.
Details on the methodology used for scenario analysis, including the specific climate models and assumptions.
Confirmation that the board-level climate oversight is consistent with the issuer’s corporate governance framework.

For a Hong Kong issuer, the SEC may also request a comparison of the US disclosure with the HKEX ESG report, seeking to identify any material inconsistencies. The issuer should prepare a reconciliation memorandum that maps each HKEX disclosure item to the corresponding SEC requirement, identifying any gaps and providing a rationale for any differences.

Post-IPO Compliance: Ongoing Reporting and Assurance

After listing, the issuer must comply with both regimes on an annual basis. The SEC requires climate disclosures in the Form 20-F annual report, while the HKEX requires them in the ESG report published within three months of the annual report. The issuer should establish a single data collection and reporting system that feeds both documents, with a common data dictionary and assurance scope. The audit committee should review the climate disclosures at least quarterly, alongside the financial statements, to ensure consistency and timeliness.

Actionable Takeaways

Start the climate data collection process at least 12 months before the anticipated F-1 filing — the GHG emissions inventory requires a full fiscal year of data, and the assurance provider needs at least six months to complete the limited assurance engagement.
Engage a single assurance provider with both PCAOB and HKICPA registration to avoid duplicative work and ensure consistency across the SEC and HKEX filings.
Remove any public Scope 3 reduction targets from pre-IPO investor materials unless the issuer is prepared to bear the cost of Scope 3 assurance, which can exceed USD 300,000 per year for a complex group structure.
Draft the prospectus risk factor section to explicitly reference both the SEC’s Release No. 33-11275 and the HKEX’s Appendix 27 — this demonstrates regulatory awareness and reduces the likelihood of a comment letter on jurisdictional gaps.
Establish a board-level climate committee with at least one member holding a relevant qualification (e.g., a CFA charterholder with ESG certification or a Certified Public Accountant with climate assurance experience) to satisfy both the SEC’s board oversight requirement and the HKEX’s Appendix 27 mandate.