GRI Climate Reporting Ecosystem
Climate reporting spans GRI 305 (Emissions), ESRS E1, CDP Climate Change, and now ISSB IFRS S2. For companies navigating multiple frameworks simultaneously, understanding the data overlaps and framework-specific additions is the key to efficient multi-framework climate disclosure.
Climate reporting spans GRI 305 (Emissions), ESRS E1, CDP Climate Change, and now ISSB IFRS S2. Climate disclosure involves four major frameworks — and their emission data requirements are substantially the same, allowing a single GHG inventory to serve all simultaneously.
The climate reporting framework ecosystem
Climate disclosure involves four major frameworks — and their emission data requirements are substantially the same, allowing a single GHG inventory to serve all simultaneously.
GRI 305 (Emissions 2016): Voluntary. Covers Scope 1 (305-1), Scope 2 location and market-based (305-2), Scope 3 by category (305-3), GHG intensity (305-4), emission reductions (305-5), ODS (305-6), and air pollutants (305-7). The foundational emissions disclosure standard.
ESRS E1 (2023): Mandatory for CSRD companies. Covers the same Scope 1, 2, 3 metrics as GRI 305 but additionally requires: transition plan (E1-1); policies (E1-2); actions and resources (E1-3); targets (E1-4); energy metrics (E1-5); removals (E1-7); internal carbon pricing (E1-8); and financial effects (E1-9). ESRS E1 is substantially broader than GRI 305.
CDP Climate Change (annual): Voluntary. Covers governance (C1), risks and opportunities (C2), business strategy (C3), targets (C4), emissions methodology (C5), emissions data (C6 — same as GRI 305), energy (C8), additional metrics (C9), verification (C10), carbon pricing (C11), and engagement (C12). Overlaps approximately 70% with ESRS E1.
IFRS S2 (2023): Mandatory in ISSB-adopting jurisdictions. Covers governance, strategy, risk management, and metrics using TCFD four-pillar structure. Scope 1, 2, 3 metrics mandatory. Physical and transition risk scenario analysis mandatory. SASB industry metrics required.
For a company reporting all four: prepare ESRS E1 to the highest standard — it exceeds GRI 305 and meets most IFRS S2 requirements. Extract GRI 305 from ESRS E1-6. Submit CDP using ESRS E1 sections as responses (CDP now accepts CSRD reports). Add SASB industry metrics for IFRS S2.
The single GHG inventory — serving all frameworks
The GHG Protocol Corporate Standard is the mandatory methodology for all four frameworks — meaning one GHG inventory calculation serves all simultaneously.
Organisational boundary: Define operational control or equity share boundary once. Apply consistently across all frameworks — GRI, ESRS, CDP, and ISSB all accept both boundary approaches but require consistent application.
Scope 1 calculation: Fuel consumption × emission factor = kg CO2e. By GHG type (CO2, CH4, N2O, HFCs, PFCs, SF6, NF3) and by business activity. The same figure satisfies GRI 305-1, ESRS E1-6 Scope 1, CDP C6.1, and IFRS S2 Appendix B.
Scope 2 calculation: Electricity consumption × location-based grid factor AND market-based instrument factor. Both methods required by GRI 305-2, ESRS E1-6, CDP C6.3, and IFRS S2. Calculate both once, use everywhere.
Scope 3 calculation: All 15 categories — material ones calculated in detail, others screened and excluded with rationale. GRI 305-3, ESRS E1-6, CDP C6.5, and IFRS S2 all require Scope 3 by category. The same category-level figures serve all four.
GWP basis: IPCC AR6 GWP100 values for 2025+ reporting. One GWP table serves all frameworks — note the version used in every disclosure.
Verification: ESRS mandates limited assurance. IFRS S2 does not mandate assurance (though many jurisdictions are adding it). GRI and CDP are voluntary with optional assurance. A single limited assurance engagement covering the full GHG inventory provides verification for all frameworks simultaneously.
Framework-specific additions beyond the shared GHG inventory
Each framework adds requirements beyond the shared GHG inventory — understanding what is unique to each prevents omissions and focuses incremental effort.
GRI 305-only requirements: ODS (ozone-depleting substances) disclosure (305-6) — GRI requires this; ESRS E1 does not. Emission reductions from initiatives (305-5) — specific quantification of reductions achieved from named initiatives; ESRS E1-3 covers actions more broadly.
ESRS E1-only requirements: Transition plan with funded milestones and CapEx (E1-1, E1-3) — much more specific than CDP or GRI. Internal carbon pricing disclosure (E1-8). GHG removals separately disclosed (E1-7). XBRL tagging. Mandatory limited assurance.
CDP-only requirements: Detailed scenario analysis narrative (C3) — more extensive than ESRS E1-9 quantification. Supplier and customer engagement disclosure (C12). Verification of specific Scope 3 categories. Carbon credit purchase and retirement details.
IFRS S2-only requirements: SASB industry-specific climate metrics — supplementing cross-industry metrics with sector-specific indicators. More prescriptive scenario analysis methodology guidance (at least two scenarios, one consistent with limiting warming to 1.5°C or 2°C). Physical asset-level climate risk assessment for assets in high-risk locations.
For multi-framework reporters: prepare ESRS E1 as the master document. It satisfies GRI 305 almost entirely. It satisfies CDP Climate 70% — supplement with CDP narrative requirements. Add SASB industry metrics for IFRS S2. The incremental effort at each step is significantly less than building each framework from scratch.
Frequently asked questions
Does GRI 305 require the same emission factors as ESRS E1-6?
Both GRI 305 and ESRS E1-6 mandate GHG Protocol methodology but allow flexibility in emission factor source — DEFRA, IEA, national equivalents. Use the same emission factors for both frameworks. Disclose the factor source and version in your methodology note — this single disclosure covers GRI 305 methodology requirements and ESRS E1-6 methodology disclosure simultaneously.
Can we submit our ESRS E1 disclosure to CDP as our climate response?
Yes — CDP now accepts CSRD sustainability reports as responses to CDP questionnaires. Submit your ESRS-compliant sustainability report to CDP and cross-reference which ESRS sections answer which CDP questions. This eliminates the need to prepare a separate CDP response for the overlapping climate content.
GRI 305-4 requires GHG intensity — is this the same as ESRS E1-6 intensity?
Yes — both require GHG emissions divided by a business metric (revenue, production volume, etc.). The metric chosen should be the most meaningful for your sector. Disclose the denominator and the rationale. Using the same intensity metric in both GRI 305-4 and ESRS E1-6 ensures consistency — calculate once, disclose in both frameworks.