California has passed two new laws requiring businesses to disclose their carbon emissions and climate-related financial risks. The Climate Corporate Data Accountability Act (Senate Bill 253) requires large businesses operating in California to publicly report their greenhouse gas emissions. The Climate-Related Financial Risk Act (Senate Bill 261) mandates that companies disclose the threats they face as a result of climate change.
- SB 253 requires both public and private US businesses with revenues greater than $1B USD doing business in California to report their emissions comprehensively, including scopes 1, 2, and 3, beginning in 2026 (for 2025 data). SB 253 also requires reporting companies to get third-party assurance of their reports.
- SB 261 requires large US businesses with annual revenues over $500M USD operating in California to bi-annually disclose climate-related financial risks and their mitigation strategies to the public.
Because of its outsize influence on the global economy, California’s requirements promise to shape business practices well beyond the borders of the state.
Where California goes, the world follows. The state is home to one of the world’s largest economies, and it has a history of driving national and global change. Two new climate laws follow this trend: In 2023, the state passed The Climate Corporate Data Accountability Act (SB 253) and The Climate-Related Financial Risk Act (SB 261), in light of a growing recognition of the urgency to address the physical, human, and financial risks associated with climate change.
Thousands of organizations that do business in California will now have to provide assurance-ready carbon emissions data — including reporting on scope 3 emissions from up and down their value chains.
Businesses are already implementing changes to meet the demands of emerging regulations: A recent survey showed that a significant majority of corporate leaders say they are prepared for climate disclosure rules — and more than half said they see climate change as a risk to their business. California’s new laws cement the shift from voluntary climate reporting to mandatory reporting, further raising the bar for corporate climate action. Corporate leaders who develop strong climate reporting capabilities with audit-ready carbon accounting will be best positioned to meet these California requirements -- as well as similar regulations emerging around the globe.
カリフォルニア州の気候データ説明責任パッケージ（Climate Accountability Package）とは
In October 2023, California Governor Gavin Newsom signed SB 253 and SB 261 into law. The bills were first introduced in January 2023 by a group of lawmakers seeking to enhance transparency, standardize disclosures, and provide stakeholders and consumers with transparent and credible climate information. The Climate Corporate Data Accountability Act (SB 253) passed the state Assembly in September in a 49-20 vote.
While they’re similar to proposed federal climate disclosure regulations put forward by the SEC, California’s laws differ on several fronts.
Here’s what you need to know about the two policies:
SB253：企業気候データ説明責任法（Climate Corporate Data Accountability Act）
Passage of the Climate Corporate Data Accountability Act represents a crucial milestone in the establishment of mandatory emissions reporting regulations. The law requires large public and private US-based organizations that do business in California to disclose their greenhouse gas emissions in accordance with the GHG Protocol. The policy applies to US-based partnerships, corporations, limited liability companies, and other entities with operations in California and annual gross revenue of more than $1B USD — an estimated 5,400 companies.
Under the law, impacted companies will need to report their full carbon inventories, including scope 3 emissions. This is pivotal, as scope 3 emissions often account for more than 90% of an organization’s climate impact and are notoriously difficult to measure.
The Climate Corporate Data Accountability Act stipulates that companies will have to submit emissions calculations to a digital reporting platform, and they must make disclosures easily comprehensible to residents, investors, and other stakeholders. Notably, they will also be required to hire independent auditors to verify their reported emissions — making rigorous data collection absolutely critical.
報告内容はカリフォルニア州大気資源局が一括で管理し、炭素会計の専門性を持つ登録機関（レジストリ）または第三者監査（法）人による綿密なデータ検証が行われます。規制に準拠しない報告をした企業は、州司法長官の判断により民事制裁金を科される恐れがあります。
Enterprises will need to report on their 2025 direct emissions starting in 2026 and their 2026 indirect scope 3 emissions starting in 2027.
SB261：気候関連財務リスク法（Climate-Related Financial Risk Act）
The Climate-Related Financial Risk Act requires large businesses to prepare and submit a biannual climate-related financial risk report, publicly disclosing their climate-related financial risks and the measures they’re taking to mitigate these risks.
The bill applies to any US corporation or business entity with annual revenue over $500M USD doing business in California — a lower threshold than SB 253. Affected organizations will need to provide a climate-related financial risk report detailing the physical and transition threats they face as a result of climate change, as well as the measures they’re taking to mitigate and adapt to those risks.
Submissions will be reviewed by the Climate-Related Risk Disclosure Advisory Group, which will identify inadequate reports, as well as propose additional policy changes and best practices for disclosure.
According to its sponsors, SB 261 is modeled after existing climate disclosure rules used by the state’s teachers’ retirement fund (CALSTRS) and hundreds of major financial institutions. It aims to safeguard consumers and investors from losses resulting from climate-related disruptions to supply chains, workforces, and infrastructure, which are increasing due to the effects of climate change.
またSB261は、低炭素経済への移行に対応できない企業が、どのような潜在的財務リスクを抱えているかについても言及しています。例えば、電気自動車へのシフトに遅れをとる自動車メーカーは、市場シェアを奪われ、結果的に損失を被る可能性が高い、というようなことです。
Now that Governor Newsom has signed SB 261 into law, the initial round of climate risk disclosure reports will be due by January 1, 2026.
SB253/SB261が持つ大きな影響力
California’s climate disclosure package heralds a new era for corporate sustainability. Thousands of businesses will now have to share their emissions profiles, which will likely lead to significant carbon reductions. The laws ratchet up the pressure on large corporations — the heaviest emitters of greenhouse gases — to decarbonize. Consumers and regulators will be able to readily identify companies that are falling behind and encourage them to take climate action. Moreover, the law will protect investors by exposing entities that are vulnerable to substantial climate-related financial risk.
In a rapidly changing global landscape, a company’s climate data increasingly affects access to capital. Climate-forward companies stand to benefit from California’s policies. If a business has already been measuring and mitigating its emissions and climate risks, the new reporting framework will allow them to showcase those initiatives.
Though the bills apply only to entities doing business in California, they reflect a global push for increased transparency in carbon accounting. The state’s laws are part of a wave of climate disclosure laws that include the European Union’s Corporate Sustainability Reporting Directive (CSRD) and pending regulations from the US Securities Exchange Commission (SEC).
These developments answer a demand from investors to obtain consistent, comparable, reliable information that can help them integrate climate-related financial information into their investment decisions. A growing number of enterprises have made commitments to achieving net zero emissions. Enhanced transparency will enable investors to assess whether companies are greenwashing, or genuinely making progress toward these climate commitments.
The laws could also help businesses identify value-creation opportunities. Accurate carbon accounting allows companies to gain a deeper understanding of their emissions profiles, as well as quickly identify hotspots such as high-emitting suppliers. In a rapidly changing marketplace, the ability to provide investor-grade climate data can help build trust and secure investments. It can also add a competitive advantage: Consumers are increasingly willing to pay a premium for sustainable brands and change their buying behavior to reduce their carbon footprints.
The new laws make California the first state in the US to require climate transparency at this level — and they will have a ripple effect beyond the state’s borders. California is a major player in global markets and is rapidly moving up the ranks to become the world's fourth-largest economy, overtaking Germany. It has used its market muscle to push for global change before — most notably with its ambitious tailpipe regulations for automakers.
Enactment of SB 253 and SB 261 represents a pivotal moment for climate action.
これまでの経緯
In 2022, a bill similar to the Climate Corporate Data Accountability Act (SB 253) faced a close call in the Assembly, falling short by just one vote, following opposition from powerful interest groups.
The landscape has shifted since then. Over the past year, the coalition of businesses and advocates supporting the policy ballooned. In 2023, heavy hitters including Microsoft, Apple, Adobe, Patagonia, and IKEA joined forces to endorse SB 253.
At the same time, the intensity of disasters ravaging California fueled demand for climate action from impatient voters. Against this backdrop, more and more companies began initiating voluntary disclosures, and a growing number of investors began demanding net zero commitments and pushing for increased transparency about climate-related financial risks.
It's not surprising that Sacramento is leading the charge on corporate climate accountability. In the last decade, California has been hit hard by wildfires, floods, and other climate-related disasters. Without prompt measures to reduce greenhouse gas emissions, the state’s finances, economy, and environment are at grave risk.
SB 253 and SB 261 set a new standard for corporate transparency, and could ignite similar efforts across the country.
SECの気候情報開示規則案との比較
While California’s SB 253 shares common ground with the SEC’s climate proposal, it extends beyond the federal rule on two critical fronts: the type of emissions reported, and the type of company required to report them.
The SEC proposal would require all public companies to disclose scope 1 (direct emissions from their owned operations) and scope 2 (indirect emissions from purchasing electricity, steam, heating, and cooling) emissions. Businesses would only report on scope 3 emissions if they have set scope 3 reduction targets or if scope 3 emissions are deemed material. Moreover, smaller companies would not have to report their scope 3 emissions.
SEC提案と比較して、カリフォルニア州の規制は、さらに踏み込んだ内容となっています。カリフォルニア州法案では、同州内で事業を行う年間売上高10億ドル以上の米国企業に対し、スコープ1、2、3すべての排出量を開示するよう義務付けます。スコープ3が開示範囲に含まれているかどうかの違いは非常に重要です。なぜなら、多くの企業のGHG排出量内訳のうち、大部分を占めるのがスコープ3だからです。
The other notable difference between the regulations is the type of company involved. While the proposed SEC rule applies only to publicly traded companies, California’s policy targets both public and private entities. This could help drive decarbonization of the private market and would enable investors to initiate climate action across multi-asset portfolios.
カリフォルニア州の新規制へ準拠するため今から準備を
The world is rapidly shifting to a low-carbon economy, and California’s climate accountability laws will further speed that transition.
企業がまず取り組むべきことは？ 気候関連情報の開示に向けた行動計画の策定です。カリフォルニア州で事業を展開する大企業の場合、遅くとも2025年から排出量データの収集に取り掛からなければ、2026年の報告要件を遵守することができません。
You must now handle your climate data with the same level of care as your financial data, which means you need rigorous internal processes and controls. Persefoni’s carbon accounting platform ensures that your emissions calculations are traceable, transparent, and reliable. We help you efficiently build auditable, investor-grade reports, so you can confidently disclose under California’s new policy — while preparing for future federal and global mandates.
Learn more about how Persefoni can help you get ready for reporting under California’s Climate Accountability Package.
よくある質問 （FAQ）
Who does CA SB 253 affect?
The law applies to public and private businesses with more than $1B USD in revenue and doing business in California.
カリフォルニア州で「事業を行う」の定義とは？
As the law is currently written, this is not yet clear. The definition likely will be spelled out through rules that implement the law. However, for now, some people are looking to the State of California Franchise Tax Board, which defines “doing business in California” as meeting any of the following criteria:
- Engaging in any transaction for the purpose of financial gain within California
- カリフォルニア州に組織または商業拠点が置かれている
- Your California sales, property, or payroll exceed the following amounts:
- 2022年の場合、同州内の売上が690,144ドル（約1億250万円）以上（基準額または売上総額の25％）
- 同州内で保有する不動産および有形動産価値が69,015ドル（約1,025万円）以上（基準額または総資産の25%）
- 同州内の給与支払額が69,015ドル（約1,025万円）以上（基準額または給与総額の25％）
To be clear, SB 253 does not explicitly state that this is the definition — the final criteria may include revenue from financial reporting, taxes, or some other source. The California Air Resources Board (CARB) is charged with clarifying this and other details of the law. Based on existing standards, however, it is likely that the bar for “doing business in California” could be quite low.
It’s not uncommon to pass a law before this level of detail is settled. When the General Data Protection Regulation in Europe was developed, the threshold for which companies would have to be in compliance was developed after the regulation was approved.
企業はいつからカリフォルニア州法SB253に基づく排出量の報告を開始する必要があるか？
By 2026, companies will need to adhere to Greenhouse Gas Protocol (GHGP) standards for measuring and reporting scope 1 and 2 emissions based on the prior fiscal year’s data. They will also need to obtain limited third-party assurance for scope 1 and 2 emissions. By 2027, companies will need to adhere to the GHGP standards for measuring and reporting scope 3 emissions based on the prior fiscal year’s data. By 2030, companies will need to obtain reasonable, third-party assurance for their scope 1 and 2 emissions reporting, as well as limited third-party assurance for their scope 3 emissions reporting.
カリフォルニア州法SB253が中小企業に与える影響は？
Companies under $1B USD in revenue will not be directly subject to California SB 253. However, we expect that the inclusion of scope 3 in the law will lead to increased pressure throughout value chains for scope 1 and 2 emissions disclosures, as these help larger companies report on scope 3. Many large companies already report their scope 3 emissions, with minimal reported burden on small businesses.
カリフォルニア州法SB253施行に向けて企業が取るべき対策は？
The bottom line is that companies need to focus on controls and transparency. As we move from a voluntary reporting landscape to a regulated one, emissions data will be treated in a similar manner to financial data — it will need to undergo intense financial and legal internal review, as well as third-party assurance. In this atmosphere, companies need to be confident in their data and they must be able to show their work. Technology that automates carbon accounting is crucial to ensuring that data is transparent, traceable, and reliable.
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