Sustainability Atlas
Climate Finance & Markets·13 min read··...

Playbook: adopting Corporate climate disclosures in 90 days

A step-by-step rollout plan with milestones, owners, and metrics. Focus on materiality, assurance, data controls, and reporting-operating model design.

Only 42% of companies required to report under the Corporate Sustainability Reporting Directive (CSRD) in 2025 expressed full confidence in meeting disclosure requirements, according to a PwC survey of 215 C-suite executives. Meanwhile, data quality remains the primary obstacle for 59% of organisations, and just 38% of Wave 1 companies have completed their double materiality assessments. The regulatory clock is ticking: approximately 11,000 companies published their inaugural CSRD reports in 2025, with another 39,000 preparing for compliance by 2027. For engineering teams tasked with building the data infrastructure underpinning these disclosures, the 90-day implementation window is not aspirational—it is the operational reality.

This playbook provides a structured approach to deploying disclosure-ready systems across your organisation, covering materiality frameworks, assurance integration, data controls architecture, and the reporting operating model that connects sustainability metrics to auditable outputs.

Why It Matters

The EU's CSRD represents the most significant expansion of mandatory sustainability reporting in corporate history. By 2027, approximately 50,000 companies—including non-EU entities with €150 million or more in EU revenue—will fall under its scope. Unlike voluntary frameworks, CSRD mandates machine-readable XHTML reports tagged with ESRS taxonomies, third-party assurance, and comprehensive Scope 1, 2, and 3 emissions disclosures.

For engineering teams, this translates into concrete technical requirements. Data pipelines must ingest emissions factors from procurement, logistics, and energy systems. Double materiality assessments require structured stakeholder inputs mapped to EFRAG's 1,100+ disclosure requirements. Assurance providers need audit trails demonstrating data lineage from source systems to published metrics.

The business case extends beyond compliance. Companies with robust sustainability data infrastructure report 52% better stakeholder engagement and 57% improved environmental performance, according to the same PwC study. LEED-certified buildings command 13-36% sales premiums, and green bonds now represent €500 billion in annual issuance—capital increasingly contingent on verified disclosure quality.

The 90-day timeline reflects the compressed implementation windows many organisations face. With Wave 2 reporting requirements shifting from 2026 to 2027 under the February 2025 Omnibus proposal, companies have a narrow window to build systems before regulatory deadlines become immovable.

Key Concepts

Double Materiality

CSRD's defining requirement, double materiality, assesses sustainability from two perspectives: impact materiality (how your operations affect people and planet) and financial materiality (how environmental and social factors affect your financial performance). This bidirectional analysis determines which of the 12 ESRS topical standards apply to your organisation.

The process typically involves creating a longlist of 40-100 potential impacts, risks, and opportunities (IROs), then scoring each against thresholds for scale, scope, and irremediability. ABN AMRO's 2024 CSRD report demonstrates this approach: the Dutch bank mapped its real estate financing portfolio to climate impacts while simultaneously assessing transition risks to its loan book. The result is a focused set of material topics—typically 8-15—that drive disclosure requirements.

Assurance Readiness

CSRD mandates limited assurance initially, with reasonable assurance expected from 2028. The November 2024 release of ISSA 5000—the International Standard on Sustainability Assurance—establishes the global reference framework that EU regulators will adopt.

For engineering teams, assurance readiness means implementing controls that demonstrate data integrity. This includes automated reconciliation between source systems and consolidated reports, timestamp-verified data captures, and segregation of duties in emissions calculations. Companies should expect assurance providers to test controls, not just recalculate figures.

Data Controls Architecture

Climate disclosure data flows through multiple systems: ERP platforms for procurement and energy spend, IoT sensors for facility emissions, supply chain management tools for Scope 3 calculations, and consolidation engines for entity-level reporting. Each handoff introduces potential errors.

A robust controls architecture implements validation at three levels: source system integrity (is the energy bill accurate?), transformation accuracy (are emissions factors correctly applied?), and aggregation completeness (are all entities consolidated?). The goal is a defensible audit trail from meter reading to published metric.

Reporting Operating Model

The operating model defines who owns what across the disclosure cycle. Typical configurations include:

  • Federated model: Business units own data collection; central sustainability team owns consolidation and narrative.
  • Centralised model: Shared services centre manages end-to-end data flows; business units provide inputs.
  • Hybrid model: Centres of excellence for complex calculations (Scope 3, scenario analysis); distributed ownership for operational data.

VodafoneZiggo's 2024 integrated report illustrates the hybrid approach: central sustainability governance sets targets and methodology, while local teams execute CO₂ reduction initiatives within that framework. The company achieved a 25% year-over-year emissions reduction through this structure.

What's Working

Early Mover Advantage in Data Infrastructure

Ahold Delhaize's first CSRD-compliant report demonstrates the value of systematic data investment. The Dutch retailer deployed €2.3 billion in sustainability infrastructure—refrigeration systems, renewable energy, supply chain monitoring—and built the data pipelines to report against ESRS E1 (climate) and S1 (own workforce) standards. The result is disclosure that connects concrete investments to measurable outcomes: energy consumption per square metre, supplier compliance rates, and transition plan milestones.

Integrated Software Platforms

Carbon accounting platforms have matured significantly. Watershed, valued at $1.8 billion following its February 2024 Series C, offers one-click workflows for CSRD, SEC, and TCFD reporting with embedded regulatory guidance. Persefoni serves four of the top 10 private equity firms with audit-grade financed emissions calculations. Sweep—Paris-based and CSRD-focused—emphasises collaborative task management for distributed teams.

These platforms reduce implementation timelines from months to weeks by providing pre-built emission factor libraries, ESRS-aligned disclosure templates, and integration connectors for common ERP and procurement systems. The European carbon accounting software market reached €5.62 billion in 2024 and is projected to grow at 22.95% CAGR through 2033.

Stakeholder Engagement as Data Source

Grenergy's 2024 double materiality analysis demonstrates effective stakeholder integration. The renewable energy company conducted two-level analysis: an agnostic assessment of transversal ESG issues (drawing from GRI, ratings frameworks, and NFRD) and a company-specific review aligned with its 2024-2026 ESG Roadmap. Material topics—climate mitigation, biodiversity, circular economy—emerged from structured dialogue rather than internal assumptions.

What's Not Working

Scope 3 Data Quality

Despite representing 70-90% of total emissions for most companies, Scope 3 data remains the weakest link in disclosure chains. The ISSB's December 2025 amendments eased Category 15 (financed emissions) requirements for financial institutions precisely because data quality proved inadequate for reliable measurement.

The core problem is supply chain opacity. Tier 1 suppliers may provide emissions data, but Tier 2+ suppliers rarely have the capability. Companies resort to spend-based estimates using sector-average emission factors—a methodology that obscures actual performance and limits year-over-year comparability.

Engineering solutions include supplier engagement platforms that simplify data collection, API integrations with supplier ERP systems, and machine learning models that estimate emissions from procurement patterns. However, these require significant investment and supply chain cooperation that many organisations lack.

Standards Fragmentation

Companies operating globally face overlapping requirements: CSRD in the EU, SEC climate rules (currently stayed) in the US, ISSB-aligned mandates in the UK, Australia, and Hong Kong. While EFRAG and ISSB published interoperability guidance in May 2024, practical alignment remains challenging.

The divergence manifests in materiality definitions (double materiality vs. financial materiality only), reporting boundaries (value chain scope differences), and assurance standards (ISSA 5000 vs. jurisdiction-specific requirements). Engineering teams must build systems flexible enough to produce multiple outputs from unified data sources.

Assurance Capacity Constraints

With 11,000 companies reporting in 2025 and 50,000 expected by 2027, the assurance profession faces acute capacity constraints. The Big Four—holding 67% of sustainability assurance engagements—are hiring aggressively, but qualified sustainability assurance professionals remain scarce.

The practical impact: extended engagement timelines, premium pricing, and limited availability for pre-year-end advisory. Companies should engage assurance providers at project inception, not at report completion.

Key Players

Established Leaders

  • Deloitte — Global leader in sustainability assurance with $21 billion in annual assurance revenue. AERS (Audit & Enterprise Risk Services) division provides CSRD readiness assessments, controls design, and limited assurance engagements across EU operations.

  • PwC — Published the definitive CSRD readiness survey; offers integrated advisory combining regulatory interpretation, data architecture, and assurance. Strong presence in financial services sector for PCAF-aligned disclosures.

  • Workiva — Enterprise platform connecting sustainability data to financial reporting workflows. XBRL tagging capabilities aligned with ESRS taxonomy requirements; used by Fortune 500 companies for SEC and CSRD filings.

  • SAP Sustainability Control Tower — Integrated sustainability management within SAP ERP ecosystem. Enables real-time emissions tracking, target monitoring, and disclosure generation from operational data.

Emerging Startups

  • Watershed — San Francisco-based, $1.8 billion valuation. Acquired VitalMetrics (2024) for enhanced supplier data capabilities. First PCAF-accredited carbon accounting provider; serves Walmart, Airbnb, and Stripe.

  • Persefoni — Mesa, Arizona; $194 million raised through Series C. Built for financial institutions requiring audit-grade financed emissions calculations. Partnerships with Bain & Company and AWS.

  • Sweep — Paris-headquartered, €100 million funding from Coatue. CSRD-native platform with collaborative task management for distributed teams. SAP and Microsoft Dynamics integrations launched 2024-2025.

  • Normative — Stockholm-based AI-driven carbon accounting. Strong European SME focus with automated data collection and ESRS alignment.

Key Investors & Funders

  • EU Innovation Fund — €3.6 billion committed to green industrial projects, including sustainability data infrastructure and reporting technology.

  • Breakthrough Energy Ventures — Bill Gates-backed fund investing in climate technology including emissions measurement and reporting platforms.

  • Coatue Management — Led Sweep's funding rounds; active in climate tech SaaS investments across Europe and North America.

  • TPG Rise Climate — $7.3 billion climate fund; invested in Persefoni's Series C extension alongside Rice Investment Group.

Action Checklist

  • Week 1-2: Establish governance structure — Appoint a disclosure programme lead with authority to coordinate across finance, operations, and IT. Define RACI matrix covering data owners, control owners, and assurance interfaces.

  • Week 3-4: Complete double materiality assessment — Use EFRAG's Implementation Guidance 1 to create IRO longlist. Engage stakeholders through structured surveys. Score impacts against scale, scope, and irremediability thresholds. Document methodology for ESRS 2 IRO-1 and IRO-2 disclosures.

  • Week 5-6: Map data sources to disclosure requirements — For each material topic, identify source systems, data owners, and current collection frequency. Gap analysis should highlight missing data streams (particularly Scope 3 categories) and quality issues.

  • Week 7-8: Deploy carbon accounting platform — Select and configure platform aligned with company scale and complexity. Integrate with ERP, procurement, and energy management systems. Establish emission factor libraries and calculation methodologies.

  • Week 9-10: Implement data controls — Design three-level control framework: source validation, transformation accuracy, aggregation completeness. Automate reconciliations where possible. Document control descriptions for assurance providers.

  • Week 11-12: Engage assurance provider — Brief selected provider on data architecture, control environment, and reporting timeline. Schedule interim testing and year-end fieldwork. Agree on management representation letter requirements.

  • Week 13: Produce draft disclosures — Generate ESRS-aligned outputs from platform. Review against EFRAG sector-specific guidance where applicable. Circulate for internal comment.

  • Week 14: Finalise and tag for XHTML — Complete narrative disclosures. Apply ESRS taxonomy tags. Conduct technical validation of machine-readable format.

FAQ

Q: How do we handle Scope 3 emissions when supplier data is unavailable?

A: CSRD permits a phased approach. Start with spend-based estimates using sector-average emission factors from databases like DEFRA or ecoinvent. Prioritise primary data collection for material categories—typically purchased goods and services, upstream transportation, and use of sold products represent 80%+ of Scope 3 for most companies. Deploy supplier engagement platforms that simplify data requests through standardised templates. ISSB's December 2025 amendments provide additional relief for financed emissions, limiting Category 15 requirements to loans and investments rather than full financial intermediation activities. Document your methodology evolution for year-over-year comparability.

Q: What level of assurance is required, and how do we prepare for reasonable assurance in 2028?

A: CSRD initially requires limited assurance—a lower threshold where the assurance provider states they are "not aware of any material misstatement." Reasonable assurance, expected from 2028, requires positive confirmation that disclosures are "free from material misstatement." Preparation involves strengthening data controls now: implement automated reconciliations, establish clear audit trails from source to report, and build segregation of duties into your operating model. Engage your assurance provider for annual controls testing rather than year-end only. The transition from limited to reasonable assurance should be evolutionary, not revolutionary, if controls are properly designed from inception.

Q: How do we manage the interoperability between CSRD/ESRS and ISSB standards for global reporting?

A: EFRAG and ISSB published interoperability guidance in May 2024 addressing the relationship between European and international standards. The core difference is materiality scope: ESRS requires double materiality (impact and financial), while ISSB S2 focuses on financial materiality only. Practical approach: build your data architecture around ESRS requirements—the more comprehensive standard—and configure platform outputs for both frameworks. Most carbon accounting platforms now support multi-framework reporting from unified data sources. For entities reporting under both regimes, maintain a single calculation engine with framework-specific presentation layers.

Q: What is the realistic timeline for full disclosure maturity, and how do we communicate progress to stakeholders?

A: First-year CSRD reports will inevitably contain gaps. EFRAG acknowledges this through transition reliefs—for example, the first year permits focus on IFRS S2 (climate) before expanding to full ESRS coverage. Communicate maturity honestly: disclose which data is estimated versus measured, which Scope 3 categories lack supplier-specific data, and what your improvement roadmap targets. VodafoneZiggo's approach—publishing concrete interim results (45% CO₂ reduction achieved versus 50% target) alongside remaining work—demonstrates that transparency builds rather than erodes stakeholder confidence. Plan for three-year maturity: year one establishes baseline and architecture; year two improves data quality and coverage; year three achieves steady-state reporting with reasonable assurance.

Q: How should engineering teams prioritise CSRD requirements when resources are constrained?

A: Focus on climate disclosures first (ESRS E1), as they represent the highest regulatory scrutiny and investor attention. Within E1, prioritise Scope 1 and 2 emissions—these are directly measured and form the foundation for credible reporting. Build the data architecture to accommodate Scope 3 expansion without re-platforming. For social disclosures (S1), most companies have existing HR data systems that can be adapted with moderate effort. Governance disclosures (G1) typically require documentation rather than new data collection. The 80/20 rule applies: E1 and S1 own workforce typically cover 80% of material topics for most industrial companies. Invest engineering effort there before expanding to biodiversity, circular economy, or value chain worker disclosures.

Sources

The 90-day timeline for CSRD implementation is demanding but achievable for organisations that approach disclosure as an engineering challenge rather than a compliance exercise. The companies leading in this space—ABN AMRO, VodafoneZiggo, Ahold Delhaize—have built data architectures that connect operational reality to stakeholder communication. For engineering teams, the opportunity is to create systems that not only meet regulatory requirements but generate genuine insight into organisational sustainability performance. The disclosure infrastructure you build today becomes the foundation for transition planning, capital allocation, and strategic decision-making in the decade ahead.

Topics

corporatedisclosurestransition financecomplianceScope 3ISSBblended finance

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