Category: ESG Metrics

Updated Nov 1, 2026 — added the free scope 3 quick card, specialty-trades field pack, and field-data coach downloads to this guide.

Most Scope 3 inventories are built on a fiction of convenience: money spent, multiplied by an industry-average factor. The method — spend-based estimation, usually via environmentally extended input-output (EEIO) models — cannot see that one contractor runs new equipment and another runs old, that one job landfilled everything and another recycled half. It prices the invoice, not the work. For recurring vendors with contracts and billing systems, companies are slowly replacing those proxies with primary data: actual fuel, hours, materials and waste from the supplier’s own operations. For reactive specialty trades — the restoration crew dispatched at 2 a.m., the emergency mechanical repair, the one-off strip-out — almost nobody collects anything. The work is procured under duress, invoiced in lump sums, and either omitted from the inventory or buried inside a spend factor. This guide is about closing that specific gap: what to capture, whose boundary it belongs in, and how to make a field crew’s paperwork into auditable carbon data.

Why the proxies are on their way out

Scope 3 is the bulk of most footprints — CDP puts the average at roughly 75% of a company’s total emissions, with sector figures ranging from about 70% to over 90% — so the quality of Scope 3 data is the quality of the inventory. Three forces are pushing from estimates toward activity data:

• California’s SB 253 requires Scope 1, 2 and 3 reporting for companies doing business in the state above $1 billion in revenue, with Scope 3 phasing in from 2027 (the full regime is in our SB 253 / SB 261 compliance playbook). The categories where specialty-trade emissions concentrate are Category 1 (purchased goods and services) and Category 5 (waste generated in operations).
• The EU’s CSRD / ESRS E1 requires value-chain disclosure under double materiality. Estimates are permitted where primary data cannot be obtained with reasonable effort — but assurance expectations ratchet, and a number you cannot trace to an activity is a number an assurer will eventually challenge.
• The GHG Protocol’s Scope 3 Standard is being revised for the first time since 2011. Its Phase 1 progress update (March 2026) proposes exactly the direction this guide assumes: companies would disclose what share of their Scope 3 data is primary, activity-based or spend-based, account for at least 95% of reportable Scope 3 emissions, and use granular supplier data rather than allocating a diversified supplier’s company-wide footprint. A consultation draft of the consolidated standard is expected in 2027. These are proposals, not law — but nobody builds a data system against the direction the standard-setter just announced.

The reactive-trade blind spot

Recurring vendors and emergency trades fail data collection for opposite reasons. Recurring services — janitorial, landscaping, scheduled maintenance — run through RFPs and multi-year agreements; the survey goes out once a year and someone answers it. Reactive trades are dispatched first and paperworked later, if at all:

Three root causes compound. Duress procurement: when the pipe has burst, nobody onboards the vendor into an ESG portal before dispatch. Tiered subcontracting: the prime contractor’s invoice covers spot labor, sub-trades and rental equipment whose fuel and hours the prime never sees. Schema mismatch: standard vendor surveys ask for company-level Scope 1 and 2 totals, which a twelve-person restoration firm cannot translate into the carbon content of your specific job. The fix is not a better survey. It is a job-level field set the crew can actually complete.

Whose emissions are they? The occupier–owner boundary

Emergency work inside a leased space belongs in the occupier’s Scope 3 — and getting this boundary wrong creates both double counting and gaps.

The allocation follows control: the occupier contracts the service, defines the scope, approves the invoice and controls access to the space. One nuance worth capturing in the data model: where drying equipment and air scrubbers plug into tenant-metered power, that electricity is the occupier’s Scope 2 — the service is Category 1, the kilowatt-hours may already sit in the tenant’s own utility data. A field set that records both the equipment hours and the power source keeps the two from being counted twice or not at all.

A 12-field job-level intake schema

What follows is a field set this guide proposes — lift it, rename it, adapt the units to your region. It is deliberately small: twelve fields a dispatcher or crew lead can complete from the work order, the fuel log and the waste ticket. Every field maps to a GHG Protocol category so the payload drops into an inventory without translation.

Field 12 is the one that future-proofs the rest. The GHG Protocol revision proposals would have companies disclose the share of primary versus estimated data. A payload that already flags which numbers were measured and which were estimated converts that disclosure from a research project into a filter.

Making it contractual: the MSA data rider

Voluntary data requests lose to emergency conditions every time; a payment condition does not. The mechanism that works is a rider in the master services agreement tying the field data to invoice approval. Model language, to be adapted by your own counsel:

Contractor agrees that submission of operational activity data — conforming to the job-level intake schema in Exhibit [X] — is a condition of final work-order approval and invoice disbursement. For all emergency, mechanical and specialty trade services, Contractor shall submit complete field logs detailing (a) equipment operating hours and fuel sources, (b) total transport mileage, (c) mass and classification of demolished debris, and (d) certified waste disposal pathways. Failure to provide complete metrics within fifteen (15) business days of job completion shall withhold invoice payment until data verification is resolved.

Fifteen days is negotiable; the structure is not. Data as a deliverable, with a deadline, attached to the money.

The rollout, in three phases

Phase 1 — pre-qualification. Register specialty-trade vendors in the CMMS alongside recurring vendors. Collect the baseline once: fleet composition, equipment wattage profiles, waste-hauling partners and their disposal facilities. Execute the MSA rider at renewal — or immediately, by amendment, for your highest-volume emergency vendors.

Phase 2 — dispatch and execution. Work orders issue pre-populated with the twelve fields, so the schema arrives with the job instead of chasing it. Crews log equipment deploy times, generator fuel draw and vehicle trips on the same mobile form they already use for job notes. If the form adds more than a few minutes to closeout, it will be abandoned by the third emergency — design for the 2 a.m. version of your vendor, not the office version.

Phase 3 — reconciliation and invoicing. The completed payload travels with the itemized invoice. Run one validation that catches most fabrication and most error: logged equipment runtime against billed labor hours — the two should move together. Then export validated payloads to the accounting platform, mapped to emission factors (regional grid factors such as eGRID for electricity; established waste coefficients such as EPA WARM for disposal pathways), and the Category 1 and 5 lines stop being estimates.

Finally, benchmark the transition honestly. Run one reporting cycle with both methods live: the old EEIO spend factor and the new primary data, side by side, for the same jobs. The gap between them — per job type, per vendor — is your evidence for what the proxies were hiding, and it is the exhibit that justifies the programme’s cost in the next budget round. Our compliance frameworks map shows where this data feeds once collected — CSRD, ISSB and California all draw on the same activity records.

Frequently asked questions

Which Scope 3 categories cover emergency restoration and specialty-trade work?

Primarily two: Category 1 (purchased goods and services) for the service itself, its fuel, transport and materials; and Category 5 (waste generated in operations) for demolished material and its disposal pathway. Electricity drawn from the occupier’s own metered supply sits in the occupier’s Scope 2 — record the power source so it is counted once.

Can we keep using spend-based estimates?

For now, in most regimes, yes — ESRS permits estimates where primary data cannot be obtained with reasonable effort, and the current GHG Protocol standard accepts spend-based methods. The direction is against them: the Protocol’s revision proposals would require disclosing how much of the inventory is spend-based and would restrict company-wide supplier allocations. Spend-based is a bridge, and bridges have a far bank.

Who reports the emissions — the tenant or the landlord?

Both, in different scopes, without double counting if the boundary follows control. The occupier reports the contracted work in Scope 3 Categories 1 and 5; the owner reports base-building energy in Scope 1 and 2 and the leased asset in Category 13. Building-performance regimes like NYC LL97 and DC BEPS assess the asset, which is the owner’s filing problem — powered by data both parties have reason to keep straight.

Is the 12-field schema an official standard?

No. It is a field set proposed by this guide, designed so every field maps to an existing GHG Protocol category. The standards — GHG Protocol, ESRS, CARB’s SB 253 rules — specify what must be reported; the job-level capture mechanism is each company’s own design problem, and this is a workable one.

When does Scope 3 reporting start under California’s SB 253?

Scope 3 phases in from 2027 for in-scope companies, on the schedule CARB sets; Scope 1 and 2 come first (2026 cycle). The operational implication: the data systems for Scope 3 need to exist before the first Scope 3 year opens, which is why vendor intake belongs in contracts being renewed now.

Sources: GHG Protocol Corporate Value Chain (Scope 3) Standard (2011) and Scope 3 Standard revision Phase 1 Progress Update (March 31, 2026), incl. Data Quality Indicator and 95% coverage proposals; CDP supply-chain reporting (Scope 3 averaging ~75% of total emissions); MIT Center for Transportation and Logistics, State of Supply Chain Sustainability 2024; California SB 253 and CARB’s implementing regulation (see the compliance playbook linked above); ESRS E1 value-chain provisions. Framework positions are as published at the time of writing; the GHG Protocol items marked as proposals are draft revision content, not final standard text.

Five agencies dominate ESG ratings, and they are not grading the same thing. MSCI asks how exposed a company is to financially material ESG risk compared with its industry. Sustainalytics asks how much of that risk is left unmanaged, in absolute terms. ISS ESG asks a double question — financial risk and outward impact. CDP grades environmental disclosure and action through its own questionnaires, and EcoVadis scores the management system a supplier actually runs. A company can be a leader in one of these frames and a laggard in another, and both grades can be honestly earned. With ESG ratings now feeding index construction, credit analysis, supply-chain qualification and — since the EU brought rating providers under authorization — regulatory scrutiny of the raters themselves, issuers need to know which question each agency is asking before they try to improve the answer.

The five at a glance

How each one actually scores

MSCI: industry-relative, controversy-deducted

MSCI selects a set of Key Issues for each GICS sub-industry and scores every company 0–10 on each, then weights them into one score that maps to the AAA–CCC letter band. Governance — corporate governance and corporate behaviour — is assessed for every company under a deduction model: each company starts at 10 and loses points for gaps against best practice. Environmental and social weights swing hard by sector, heavy for mining and utilities, lighter for services. Controversies enter as arithmetic, not adjectives: MSCI’s methodology deducts from 0 to −5.0 points from the affected Key Issue’s management score depending on the controversy’s severity, status and the company’s role in it, and a case scored 0 on MSCI’s separate controversies scale is a Very Severe red flag. There is no separate letter cap — the deduction is the mechanism, and a bad enough one moves the grade by itself.

Sustainalytics: one subtraction

The ESG Risk Rating is a single subtraction: unmanaged risk = exposure − managed risk. Exposure starts at industry level and adjusts for the company’s actual activities; managed risk scores the policies, programmes and metrics the company runs against that exposure. The result lands in one of five bands — Negligible (under 10), Low (10–20), Medium (20–30), High (30–40) and Severe (40 and above). Controversies are tracked as events in five categories, from Category 1 (low impact) to Category 5 (severe, systemic). A Category 5 event feeds straight into the management assessment, which is why a company with beautiful written policies can still watch its score worsen after an incident: the model prices what happened, not what was promised.

ISS ESG: two materialities, one grade

ISS ESG rates on a double-materiality model — the company’s exposure to ESG risk and its impact on the environment and society around it. Grades run A+ to D− and are decile-ranked within sector, so the grade is always a position among peers. Companies clearing their sector’s Prime threshold (the bar differs by industry) earn Prime status, which many institutional ESG funds use as an inclusion filter. Governance gets its own instrument, the Governance QualityScore — a decile score across board structure, shareholder rights, compensation and audit — and ISS layers norm-based research on top, checking conduct against the UN Global Compact, the OECD Guidelines and the UN Guiding Principles on Business and Human Rights.

CDP: a ladder you climb in public

CDP does not model you from the outside; it scores what you hand it. Its questionnaires — Climate Change, Water Security, Forests — grade companies through four levels: Disclosure (D−/D), for completeness of what’s reported; Awareness (C−/C), for understanding impacts and risks; Management (B−/B), for policies, targets and governance actually in place; and Leadership (A−/A), where verified emissions, a transition strategy and science-based targets live. You cannot skip a rung: the thresholds at each level gate the next. That makes CDP the most gameable-looking and the least gameable in practice — the grade is a function of evidence submitted, and the A List is published.

EcoVadis: the management system, audited

EcoVadis scores the system, not the story: 21 criteria across four themes — Environment, Labor & Human Rights, Ethics, and Sustainable Procurement — each assessed through a Policy → Actions → Results chain. Evidence is documentary: certifications such as ISO 14001 or 45001, audit reports, published policies with dates and owners, tracked KPIs. The output is a 0–100 scorecard and, at the top bands, the medals procurement teams use as a qualification gate. Of the five, EcoVadis is the one most companies meet first — not through an investor, but through a customer’s supplier portal.

Why the same company gets five different grades

The divergence is structural, and it has a name: aggregate confusion. In the study that named it — Berg, Koelbel and Rigobon’s Aggregate Confusion: The Divergence of ESG Ratings — correlations between major providers’ ratings of the same companies run roughly 0.38 to 0.54, where credit ratings from S&P, Moody’s and Fitch correlate above 0.95. The study decomposes the gap into three causes, and each one is visible in the five methodologies above:

The practical consequence: there is no single “ESG score” to optimize, and chasing one rater’s methodology can leave another’s untouched. What transfers across all five is the underlying evidence — measured emissions, dated policies, audit results, incident records — which is why the working strategy below is an evidence strategy, not a ratings strategy.

The raters are being regulated now, and consolidating

The EU’s ESG Ratings Regulation brings rating providers under ESMA authorization, with methodology and conflicts disclosure attached. Providers operating in the EU must show how their ratings are built, separate ESG rating activity from credit rating and consulting conflicts, and state whether a rating measures financial risk, impact, or both — the single/double materiality distinction that runs through the table above is becoming a disclosure the rater owes, not a preference it holds. Consolidation is moving in parallel: in September 2026 Glass Lewis and Clarity AI combined — proxy voting and stewardship on one side, AI-driven sustainability data on the other — into a single platform of more than 900 professionals, with the combined firm seeking authorization under the same regulation. Ratings are becoming regulated infrastructure, and the providers are reorganizing to be regulated at scale.

Working all five at once: an evidence architecture

Step one is a single source of truth: one audit-ready repository of sustainability data, mapped once to the frameworks that demand it. The same emissions inventory feeds CSRD/ESRS reporting, ISSB S1/S2 disclosure, California’s SB 253 filing (our compliance playbook covers that regime) and every rater’s questionnaire. Our compliance frameworks map shows how those frameworks overlap; the operational point is that a KPI defined five ways in five spreadsheets will eventually contradict itself in front of a rater, an auditor, or both.

Step two is to publish like the reader is a machine, because it is. Rating platforms ingest data with scrapers and automated research tools. Numbers buried in image-based PDFs, undated policy documents and narrative-only disclosures are systematically under-read. Structured tables next to the narrative, dated and versioned documents, and explicit metadata on reporting pages are unglamorous and decisive — the same disclosure, formatted for extraction, scores better than the identical disclosure formatted for a brochure.

Step three is to treat the review windows as deadlines, because they are the only appeal you get. MSCI issuers review their data profiles through the issuer portal during the comment window before scores lock. Sustainalytics runs an issuer review of the draft profile before the risk score finalizes. EcoVadis renewals reward current, signed, third-party-verified documentation. In each case the correction channel closes; a calendar that tracks all three windows — and the CDP submission cycle — is the cheapest ratings programme there is.

Step four is controversy conduct, decided in advance. When an incident lands, both MSCI’s deduction model and Sustainalytics’ event categories move on what the company demonstrably does next: a published remediation plan, independent audit findings, changed oversight. Companies that respond in public, with documents, exit controversy deductions measurably faster than companies that respond with statements. Decide who publishes what, where, before you need to.

Frequently asked questions

Why do two agencies rate the same company so differently?

Because they measure different things with different instruments at different weights — scope, measurement and weight divergence. Correlations across ESG raters run about 0.38–0.54, against 0.95+ for credit ratings. Divergence is the expected output of the methodologies, not evidence that one rater made an error.

Which rating should a company prioritize?

The one its own stakeholders actually use. Index inclusion and most passive flows run through MSCI; credit and portfolio risk teams read Sustainalytics; stewardship teams sit inside ISS; a key customer’s procurement gate is usually EcoVadis or a CDP supply-chain request. The priority order is a fact about your investor base and customer list, not about the raters.

Does a severe controversy permanently cap our MSCI rating?

No — and there is no letter cap in MSCI’s methodology. Controversies deduct 0 to −5.0 points from the affected Key Issue’s management score, scaled by severity and the company’s role, and deductions age and resolve as cases conclude and remediation is verified. The damage is real but it is arithmetic, not a life sentence.

Is CDP a rating agency in the same sense as MSCI?

Not quite. MSCI, Sustainalytics and ISS model companies from outside data whether or not the company cooperates. CDP scores a questionnaire the company submits — disclosure is the input, so a company that does not respond is scored on that absence. EcoVadis sits between the two: questionnaire-based, but evidence-audited.

What does the EU’s ESG Ratings Regulation change for a rated company?

Indirectly, clarity. Providers authorized under the regulation must disclose their methodologies, data sources and whether they measure financial risk, impact, or both. For an issuer, that means the rules of each grade become readable in a way they historically were not — appeals and preparation get easier to aim.

Sources: MSCI ESG Ratings Methodology (incl. controversy deduction table) and MSCI ESG Controversies & Global Norms Methodology; Morningstar Sustainalytics ESG Risk Ratings methodology; ISS ESG Corporate Rating and Governance QualityScore; CDP scoring methodology (Climate Change, Water Security, Forests); EcoVadis assessment methodology (21 criteria, four themes); Berg, Koelbel & Rigobon, “Aggregate Confusion: The Divergence of ESG Ratings,” Review of Finance (2022); Regulation (EU) 2024/3005 on the transparency and integrity of ESG rating activities; Glass Lewis and Clarity AI combination announcement, September 24, 2026. Provider methodologies change on their own cycles; scales and thresholds above are as published at the time of writing.

On October 12, 2026, the California Office of Administrative Law approved CARB’s Initial Regulation implementing SB 253 and SB 261, and the regulation took effect the same day. It is codified at Title 17, California Code of Regulations, sections 96070 to 96077. The approval locks in the date every covered company now works to: November 10, 2026, when the first Scope 1 and Scope 2 emissions reports under SB 253 are due. The two laws travel together but sit in very different legal positions — one is active and enforceable, the other is paused by a federal court — and a workable compliance plan has to hold both facts at once.

The two laws at a glance

The statutory homes are Health and Safety Code section 38532 (SB 253) and section 38533 (SB 261). Everything in the Initial Regulation — the definitions, the fee, the first-year relief — hangs off those two sections, and the regulation is explicitly the initial one: CARB has already previewed the 2027 rulemaking that adds Scope 3 and assurance.

Who is in scope

Applicability is tested at the individual legal-entity level, not across the corporate family. A parent does not become a reporting entity merely because a subsidiary crosses the threshold, and intercompany transactions are excluded from the revenue count. A parent may still file one consolidated report — and pay one consolidated fee — on behalf of subsidiaries that qualify on their own.

The revenue test uses “gross receipts” as defined in Revenue and Taxation Code section 25120(f)(2), counted globally, not just in California. To smooth out a single unusual year, the regulation measures revenue at the lesser of the entity’s two previous fiscal years. An entity that dipped below the line in one of the two years is measured on the lower figure.

The “doing business in California” test is the sales test from Revenue and Taxation Code section 23101, applied on sales alone. An entity is doing business in California if it is organized or commercially domiciled there, or if its California sales exceed the inflation-adjusted threshold — $757,070 for 2025 sales — or 25% of its total sales. The property and payroll prongs of the general tax test do not apply here. Two exemptions round out the picture: certain tax-exempt nonprofits are exempt from the program, and insurance companies are exempt from SB 261 only — an insurer over the $1 billion line still reports emissions under SB 253.

Which fiscal year you report

The Initial Regulation maps your fiscal year-end to the dataset the November 10 filing must carry. If your fiscal year ends between January 1 and February 1, 2026, you report fiscal 2026 data. If it ends between February 2 and December 31, 2026, you report fiscal 2025 data — for most companies, the year that closed in calendar 2025. Entities in the second group have one election worth knowing about: you may instead report your most recent fiscal year if that data is readier. The point of the mapping is that nobody is asked to close a fiscal year early to meet the deadline; the filing runs on a year that has already ended.

What the first filing contains

First-year SB 253 filings cover Scope 1 and Scope 2 only, built on the GHG Protocol Corporate Accounting and Reporting Standard. Scope 1 is the direct inventory: stationary combustion in boilers and furnaces, mobile combustion in company fleets, process emissions, and fugitive losses such as refrigerants. Scope 2 is purchased energy — electricity, steam, heating and cooling — and CARB’s guidance expects both location-based and market-based figures where the data supports them. Each filer picks one organizational boundary — operational control, financial control, or equity share — documents it, and applies it consistently. Scope 3 is expressly out of the 2026 cycle; it arrives with the 2027 rulemaking covered below.

The third door: the statement of non-reporting

CARB wrote first-year relief directly into the regulation, at section 96076(b)(1). The relief exists because of a fixed historical fact: CARB’s enforcement notice of December 5, 2024. An entity that, as of that date, was neither collecting nor in possession of Scope 1 and Scope 2 data — and was not already running a data-collection plan — does not have to invent an inventory for 2026. It files a statement instead. (Our companion piece, Three Doors Into November 10, walks the filing choice itself: data you had, data from another program, or the statement.)

Two cautions belong next to the relief. Statements may be placed on CARB’s public docket, so write yours expecting it to be read. And the relief is fact-bound: an entity that was tracking emissions on or before December 5, 2024 cannot use it, and a statement filed anyway does not become valid by being filed. What the statement buys is time — the 2027 cycle expects a real inventory, with assurance behind it.

How to file

CARB’s preferred route is its voluntary 2026 Report Intake Platform, and email is the accepted alternative. On the platform you designate a reporting contact, choose the submission type — full Scope 1 and 2 report or statement of non-reporting — and upload the report with its boundary and methodology documentation. Reports and contact information may instead be emailed to [email protected]. Either route satisfies the obligation; whichever you use, keep the system’s confirmation or your sent-mail record. In a program this new, your own filing receipt is the document everything else gets checked against.

SB 261: paused, not repealed

SB 261’s reporting duty is stayed, and the reason is a First Amendment case your board should know by name. On November 18, 2025, the Ninth Circuit enjoined enforcement of SB 261 in Chamber of Commerce v. Sanchez, No. 25-5327, while declining to touch SB 253. The court heard oral argument on January 9, 2026; as of this writing no merits decision has issued, and CARB has stated it will not enforce the law while the injunction stands. When — if — the stay lifts, the duty is a biennial climate-related financial risk report, published on the company’s website, built on the four TCFD pillars: governance, strategy, risk management, and metrics and targets, with quantitative scenario analysis optional in the first cycle. CARB has opened a public docket for companies that choose to file voluntarily in the meantime. The sensible posture for a covered entity is background readiness: draft against the four pillars now — our compliance frameworks map shows how TCFD, IFRS S2 and the California statutes line up — but file nothing under SB 261 until the court rules. Nothing about the injunction slows SB 253 by a single day.

Fees, penalties, and what happens after November 10

The program is fee-funded, and the first fee notices land a month after the first reports. CARB charges a flat annual fee per program — the program’s annual cost divided across covered entities, calculated under sections 96073 to 96075 — and will issue fee determination notices beginning December 10, 2026. Payment is due within 60 days of the notice, a parent may pay once for consolidating subsidiaries, and the fee is owed whether the entity filed data or a statement of non-reporting. Penalties sit behind the deadlines: up to $500,000 per reporting year under SB 253, and up to $50,000 under SB 261 once it is enforceable, with failure to file treated as the enforcement priority. CARB has also said, consistently since its December 2024 notice, that good-faith first-year filings made with the data an entity actually had will be met with discretion rather than penalties — which is a reason to file something honest by November 10, not a reason to file nothing.

The horizon: Scope 3 and assurance

Scope 3 starts narrow, on CARB’s July 21, 2026 workshop proposal: five categories first. They are Category 1 (purchased goods and services), Category 3 (fuel- and energy-related activities), Category 5 (waste generated in operations), Category 6 (business travel) and Category 7 (employee commuting) — the five with the most established data and methods — with the other ten categories voluntary for now. Treat the list as a proposal, not a rule: CARB expects to release draft regulatory text in late 2026 with a 45-day comment period. Assurance climbs on its own staircase alongside: no assurance for the 2026 cycle, limited assurance over Scope 1 and 2 in the 2027–2029 window, and reasonable assurance — financial-audit rigor — from 2030. A data system built for November should be built so both staircases can be climbed without rebuilding it.

Frequently asked questions

When are the first SB 253 reports due, and what has to be in them?

November 10, 2026. The filing covers Scope 1 and Scope 2 emissions for the fiscal year the regulation assigns you — fiscal 2025 for most companies — prepared under the GHG Protocol. No third-party assurance is required for this cycle, and Scope 3 is not part of it.

Our company wasn’t tracking emissions in 2024. Do we still have to file?

Yes — but what you file is a statement of non-reporting on company letterhead, signed by an authorized officer, stating that as of December 5, 2024 you were neither possessing nor collecting Scope 1 and 2 data. That statement is the compliant 2026 filing for an entity in your position. It does not carry into 2027.

Is SB 261 in force right now?

No. The Ninth Circuit enjoined its enforcement in November 2025 in Chamber of Commerce v. Sanchez, and CARB has said it will not enforce the law while the injunction stands. The obligation may return on a court ruling, so covered companies are preparing TCFD-aligned reports without filing them.

What’s the most we can be fined?

$500,000 per reporting year under SB 253, and $50,000 per reporting year under SB 261 (once enforceable). CARB has signaled enforcement discretion for good-faith first-year filings; non-filing is what it has said it will pursue first.

Does the EU’s CSRD change what we owe California?

No — they are separate regimes with separate filings, though a company reporting under both will reuse much of the same inventory. Our EU CSRD and ESRS roadmap covers the European side.

We have to pay CARB even if we filed the non-reporting statement?

Yes. The annual fee funds the program and is assessed per covered entity regardless of which filing route you took. First notices issue December 10, 2026, payable within 60 days.

Sources: California Air Resources Board, California Climate Disclosure Program — Initial Regulation, Title 17 CCR §§ 96070–96077 (approved by the Office of Administrative Law, October 12, 2026); Health and Safety Code §§ 38532–38533; Revenue and Taxation Code §§ 23101, 25120(f)(2); Chamber of Commerce v. Sanchez, No. 25-5327 (9th Cir.); CARB public workshop on 2027 reporting, July 21, 2026. Law-firm analyses consulted: WilmerHale, “Climate Disclosure Update: CARB’s SB 253 Initial Regulation Takes Effect” (Oct 20, 2026); Greenberg Traurig, “California SB 253: CARB Sets Nov. 10, 2026, Deadline” (Oct 2026). This article is general information about a new regulation, not legal advice for a specific company.

A research team at Trinity College Dublin reports that geopolymer concretes made with red mud — the residue left over when bauxite is refined into alumina — can cut the carbon footprint of cement production by 67.8% to 79.8% compared with a standard CEM II-A/L cement, counted across raw material supply, transport and manufacturing. It is one of the largest reductions claimed for any cement replacement. It is also, for now, a laboratory and early-industrial-trial result — and the researchers are unusually clear about what still has to be proven before a buyer can specify it.

What was actually measured

The project — led by Professor Sara Pavia with Dr Zehao Lei and doctoral researcher Yingjie Pan at Trinity’s School of Engineering, with industry partners Gannon Eco and McGraths Limestone (Cong) Ltd, funded through Enterprise Ireland’s Innovation Partnership Programme — works two routes. The first uses the residue as a supplementary cementitious material: replacing 20–30% of Portland cement with bauxite residue produced compressive strength comparable to standard reference concrete. The second is a one-part geopolymer — a dry binder combining the residue with other ingredients, mixed with water and aggregates on ordinary batching equipment. The headline carbon figures belong to the geopolymer route.

The comparison behind the percentages matters as much as the percentages. The benchmark is CEM II-A/L, a Portland-limestone cement that already carries less clinker than pure Portland cement — so the saving is measured against a moderately decarbonised baseline, not the dirtiest one available. And the stages counted are raw material supply, transport and manufacturing: in environmental product declaration (EPD) terms, the product stage only. A project that credited the full 79.8% at building level would be claiming more than the study measured.

On durability, the laboratory evidence is genuinely strong. Under sulphate exposure, repeated wetting and drying, and frost action, the geopolymer matched or exceeded the conventional concrete it was tested against — including 109.7% strength retention after 56 freeze–thaw cycles. Accelerated tests are the right first filter for a new binder, but they compress stress into weeks; they do not substitute for years in real structures.

Why red mud is worth the effort

Red mud is one of the largest industrial waste streams on earth, and almost none of it is used. The U.S. Environmental Protection Agency estimates roughly three billion tonnes of bauxite residue sit at active and legacy alumina sites worldwide, and that only about 2–3% of bauxite residue is reused productively. Every tonne that performs in concrete does two jobs at once: it displaces clinker, the ingredient responsible for most of cement’s emissions, and it shrinks a stored waste liability that someone otherwise has to guard indefinitely.

Gate one: workability at production scale

A binder that works in a laboratory mixer has proven chemistry; it has not yet proven it can survive a truck ride. Fresh concrete has to stay workable — retaining its slump — long enough to be transported, placed and finished, and the Trinity team names this directly: its industrial partners identify workability and set times as the challenges the current industrial trials exist to address, and the team lists maintaining slump retention as a key hurdle to commercialisation. Until trial pours at plant scale are published with their workability windows, this gate stays open — by the researchers’ own account.

Gate two: the cost of the activator, and the cost of the haul

The residue itself is close to free; what makes a geopolymer expensive is the chemistry that wakes it up. Alkali activators are the cost driver the Trinity team singles out, and the researchers are developing lower-cost, waste-derived activators precisely because current ones threaten the commercial case. Geography is the second cost: red mud exists where alumina refineries are, not where concrete is poured, and hauling a heavy, low-value residue burns both margin and carbon — and since transport sits inside the study’s boundary at the team’s own distances, a buyer elsewhere has to recount it. A credible quote needs a project-specific EPD, not the Irish trial’s percentages with a new logo.

Gate three: decades of durability — and approval to build

Structural concrete is a promise measured in decades, and no accelerated test programme is the same as a service record. The Trinity project is explicit that long-term performance validation is an upcoming phase, not a completed one. Approval is the parallel problem: alkali-activated binders do not fit the prescriptive cement standards written for common cements, the one UK performance specification drafted for them (PAS 8820:2016) has been withdrawn without replacement, and the project lists regulatory qualification as future work. Specifying this material today means a project-specific performance case — possible, but not a catalogue purchase.

The residue itself raises a question no cement buyer usually has to ask: what, exactly, is in the waste? Red mud is caustic, with high pH and salinity, and it concentrates naturally occurring radioactive material from the bauxite ore. The U.S. EPA notes elevated arsenic and chromium in some samples; it also records that the EU regulates such material in building products through an activity-concentration index, under which some EU countries already use red muds in building materials — while the United States currently approves no secondary use of the waste at all. Radiological studies of residue concretes conclude that safety is a function of dosage and source, manageable when the percentage used is controlled and screened. So the question is never “is red mud safe?” in the abstract; it is whether this residue, from this refinery, at this dosage, has passed leaching and radiological screening for this jurisdiction.

What to ask a supplier claiming numbers like these

The Trinity result deserves attention precisely because the researchers published their open questions alongside their numbers — and a supplier who cannot do the same has not earned a specification. Four questions separate a measured claim from a marketing one:

1. Show the EPD. Which cement is the comparator, and which life-cycle stages are counted? A product-stage figure against CEM II-A/L is an honest claim; the same percentage quoted without a boundary is not a claim at all.

2. Show the durability file for this mix. Which tests — sulphate, freeze–thaw, wet–dry cycling, shrinkage, carbonation — run by whom, on the formulation actually being sold?

3. Show the trial pours. Has it been batched on production equipment, transported over a realistic window, and placed? What happened to slump and set time on the way?

4. Show the residue’s papers. Which refinery supplies it, what leaching and radiological screening has been done, what dosage does the screening support, and which approval route covers the product where the project is being built?

A “yes, documented” to all four turns a striking laboratory percentage into something a procurement team can sign. Until then, the correct reading of 67.8% to 79.8% is the one its own authors give it: a major technical milestone, mid-journey.

Frequently asked questions

What is red mud? The solid waste left when bauxite ore is processed into alumina, the feedstock for aluminium. It is caustic, and the U.S. EPA estimates about three billion tonnes are stored at active and legacy sites, with only around 2–3% of residue reused productively.

Can red-mud concrete be specified today? Not as a standard catalogue material. The project lists long-term validation and regulatory qualification as upcoming phases, and alkali-activated binders sit outside the prescriptive cement standards — so use today means a project-specific performance and approvals case, backed by a mix-specific EPD and residue screening.

Sources: Trinity College Dublin, “From red mud to green concrete” (22 October 2026) — the project’s own release, including mix routes, the 67.8%–79.8% comparison against CEM II-A/L across raw material supply, transport and manufacturing, durability results and the team’s stated open questions; U.S. Environmental Protection Agency, “TENORM: Bauxite and Alumina Production Wastes”, for residue volumes, reuse rates and the regulatory position in the EU and US. Figures are reported as published by those sources; no commercial product is yet on the market.

Whole-life carbon assessment (WLCA) measures the carbon a building produces across its entire life — materials, construction, operation, maintenance, and demolition. In the UK right now, how that assessment gets done depends on where the project sits and which authority is asking, and new research from the Centre for Construction Best Practice (CCBP) puts numbers on the inconsistency: 70% of the practitioners it interviewed said current policy and regulation has weak or no influence on how WLCA is actually implemented.

That is the finding that matters. WLCA is supposed to turn carbon data into spending decisions — which design gets funded, which bid wins, which materials get specified. Data that cannot be compared from one project to the next cannot do that job, no matter how carefully it is collected.

What the CCBP research found

The Centre for Construction Best Practice opened its research in December 2025, and its initial phase ran 35 interviews and five focus groups with local authorities, contractors, and consultants. Three numbers from that work describe the current state of WLCA in UK public construction:

• 70% of respondents agreed that current policy and regulation had weak or no influence on the implementation of WLCA.
• 59% described the use of WLCA as selective — required on some projects, ignored on others.
• 58% described current policy as fragmented and inconsistent between authorities.

CCBP is now calling on the sector — contractors, consultants, engineers, planners, project managers, clients, and the wider supply chain — to submit evidence on how WLCA is used in public sector construction and infrastructure projects. Its full findings are due in 2027.

Why the inconsistency happens

There is no single national requirement, so individual local authorities have introduced their own guidance — and each local version asks for the assessment in a different way. The result is that the same building, assessed under two authorities' rules, can produce two different carbon numbers.

Conor Neild Crabb, CCBP's head of centre, described a clear common thread in the feedback: the way WLCA is approached varies significantly, and the inconsistencies have knock-on effects for the supply chain and for capital and operational spending. Michèle Young, principal development coordinator at the London Borough of Tower Hamlets, made the mechanism plain: requiring a WLCA lets authorities and industry engage in design discussions around carbon, but without a consistent national framework its potential to support net zero ambitions is limited — and the absence of a national requirement, such as the long-proposed Part Z of the Building Regulations, risks a fragmented approach that reduces the ability to compare outcomes.

Tom Roxburgh, senior sustainability consultant at Pick Everard, added the cost side: differing WLCA standards produce differing results, varying planning requirements and reporting demands have created a bloated assessment process, and one standard may cost more than another without providing better insight for reduction decisions.

What one consistent framework would have to fix

A single WLCA framework is not mainly a paperwork exercise — it has to fix five specific things before carbon data can drive spending and procurement decisions.

1. One methodology. The framework has to fix the boundary of the assessment: which life-cycle stages count, which materials and processes are in scope, and which calculation rules apply. Until two assessors measuring the same building are required to count the same things, their results are not measurements of the same quantity.

2. One trigger. WLCA is currently selective — required by some authorities on some projects. A consistent framework sets a national threshold for when an assessment is required, so the obligation does not change at a borough boundary. This is the role the proposed Part Z is meant to fill for embodied carbon in England.

3. Comparable outputs. Assessments have to report in the same format, against the same reference values, so a client can place two projects' results side by side and have the comparison mean something. Comparability is the property that turns an assessment into evidence.

4. Proportionate cost. When each authority's variant demands a new approach, project teams pay for the assessment process repeatedly — Roxburgh's "bloated" process. One framework means one approach learned once, priced once, and reused, which is what makes it reasonable to ask teams to spend money on carbon reduction rather than on compliance variation.

5. A link into decisions. The end point of the CCBP evidence call is whether consistency could help WLCA "have a greater influence on spending decisions." An assessment that is filed to satisfy a planning condition changes nothing. A framework earns its keep when the number it produces is wired into procurement scoring, design funding, and capital approval — the places where money actually moves.

Why this travels beyond the UK

The UK's WLCA problem is a specific case of a general pattern: carbon rules written at the local level, one jurisdiction at a time, produce data that cannot be compared across the line where the rule changes. Any market where building carbon obligations are set city by city or state by state should expect the same three symptoms the CCBP respondents named — selective use, fragmented policy, and weak influence on real decisions — until the methodology and the reporting format are standardized above the local level.

The sequence matters for practitioners everywhere: consistency first, then comparability, then influence. Carbon data starts driving spending only after the first two are in place.

Frequently asked questions

What is whole-life carbon assessment? Whole-life carbon assessment is the practice of quantifying a built asset's carbon emissions over its full life — extracting and manufacturing materials, transport and construction, operation and maintenance, and end of life — so design and procurement choices can be compared on carbon as well as cost.

What did the CCBP research find? In initial research involving 35 interviews and five focus groups, 70% of respondents agreed current policy and regulation had weak or no influence on how WLCA is implemented, 59% described its use as selective, and 58% described policy as fragmented and inconsistent between authorities. CCBP has opened an evidence call to the whole sector, with full findings due in 2027.

What is Part Z? Part Z is a proposed addition to the Building Regulations in England that would require the assessment — and potentially the limiting — of embodied carbon in new buildings. It is an industry-backed proposal, not current law. In the WLCA debate it stands for the missing piece: a national requirement that applies the same way everywhere.

When will the full CCBP findings be published? CCBP is continuing to gather evidence through its open call, and its full findings are expected in 2027.

Source: Construction Management, "The way we do whole-life carbon assessment is a mess, says Centre for Construction Best Practice" (October 2026), reporting CCBP's initial research and evidence call. Figures quoted are from CCBP's initial findings as reported; the research is ongoing.