GRI vs SGX Sustainability Reporting: What Singapore Companies Actually Need to Comply

The Framework Alphabet Soup

The sustainability reporting landscape has been shaped by multiple independent organisations, each with a legitimate purpose but a different origin, audience, and scope. The result is a dense web of standards that companies encounter simultaneously without a clear map of how they relate.

GRI (Global Reporting Initiative) is the oldest of the major frameworks, founded in 1997 in Amsterdam. It provides topic-specific standards across the full range of ESG issues — emissions, water, biodiversity, labour rights, anti-corruption, and dozens more. GRI 305, for example, is the specific standard covering greenhouse gas emissions. The ISSB (International Sustainability Standards Board) is a newer body, established in 2021 as part of the IFRS Foundation, the same organisation that sets global financial accounting standards. The ISSB published IFRS S1 and IFRS S2 in June 2023, with the aim of creating a single global baseline for sustainability-related financial disclosures. SGX (Singapore Exchange) is Singapore's stock exchange regulator, which sets the mandatory reporting rules for all companies listed on the Singapore exchange. The GHG Protocol is not a reporting standard but an accounting methodology — the global standard for measuring and calculating greenhouse gas emissions that sits underneath both GRI 305 and IFRS S2.

Understanding the distinction between these bodies — standard-setter versus exchange regulator versus accounting methodology — is the first step to cutting through the confusion.

GRI: The Global Reporting Standard

The Global Reporting Initiative was founded in 1997 in Amsterdam with a mission to create a universal language for companies to report their environmental and social impacts. Over nearly three decades it has become the most widely used sustainability reporting framework in the world, with tens of thousands of organisations across more than 100 countries publishing GRI-aligned reports.

GRI works through a modular system of standards. The Universal Standards (GRI 1, 2, and 3) set the foundation and determine which topics are material. The Topic Standards then provide the detailed disclosure requirements for specific issues. GRI 305 is the Topic Standard for emissions and is the most directly relevant to companies beginning their greenhouse gas reporting journey.

GRI 305-1 covers Scope 1 emissions — direct greenhouse gas emissions from sources owned or controlled by the reporting organisation. GRI 305-2 covers Scope 2 emissions — indirect emissions from the generation of purchased energy. GRI 305-3 covers Scope 3 emissions — all other indirect emissions that occur in the value chain, both upstream and downstream. GRI 305-4 requires disclosure of GHG emissions intensity (typically per unit of revenue, production, or employee). GRI 305-5 covers GHG emissions reductions — the verified reductions achieved against a base year.

Critically, GRI 305 specifies that emissions must be calculated using the GHG Protocol Corporate Accounting and Reporting Standard. This is not incidental — it means that a company doing GRI 305 reporting is already using the same underlying accounting methodology as IFRS S2. The data collected for GRI purposes can be the foundation for IFRS S2 compliance, even if the presentation and framing differ.

GRI reporting is not mandatory in Singapore for any category of company. It is, however, widely accepted as global best practice and is frequently expected by international investors, procurement teams, and rating agencies. Many Singapore listed companies report against GRI in addition to satisfying SGX requirements.

SGX: Singapore's Mandatory Framework for Listed Companies

For companies listed on the Singapore Exchange, sustainability reporting is not optional. SGX Listing Rules require all listed companies to produce an Annual Sustainability Report. This requirement has been in place since 2017 and has been progressively strengthened as global standards have converged.

The most significant recent development is SGX's adoption of IFRS S1 and IFRS S2 as the mandatory baseline for sustainability reporting from FY2025. This brings Singapore listed companies into alignment with the ISSB's global climate disclosure standard and replaces the previous TCFD-aligned requirements that SGX had been phasing in since 2022.

Under the current SGX framework, listed companies must disclose Scope 1 and Scope 2 greenhouse gas emissions calculated using the GHG Protocol methodology, embedded within the four-pillar IFRS S2 structure of governance, strategy, risk management, and metrics and targets. Assurance requirements are phased: third-party limited assurance on Scope 1 and Scope 2 disclosures will be mandatory from FY2029, with larger companies (STI constituents and those with market capitalisation above S$2 billion) facing earlier deadlines in the transition.

SGX accepts GRI reporting as evidence of meeting some of its sustainability disclosure requirements, particularly where the GRI disclosures cover the same substantive ground. However, GRI alone does not satisfy the full IFRS S2 obligation. The governance, strategy, and risk management pillars of IFRS S2 require narrative disclosures about how climate risk is integrated into board oversight, business strategy, and enterprise risk management — none of which are directly covered by GRI 305's emissions-focused requirements.

ISSB and IFRS S2: The New Global Mandatory Layer

The International Sustainability Standards Board was established in November 2021 as part of the IFRS Foundation — the same body that oversees International Financial Reporting Standards used for financial accounting in more than 140 countries. The establishment of the ISSB was a deliberate signal: sustainability disclosure should be treated with the same rigour and comparability as financial reporting.

In June 2023, the ISSB published its first two standards. IFRS S1 covers general sustainability-related financial disclosures and requires companies to disclose material sustainability risks and opportunities that could reasonably be expected to affect cash flows, access to finance, or the cost of capital. IFRS S2 is the climate-specific standard. It requires disclosures structured around four pillars: governance (how the board and management oversee climate-related risks and opportunities), strategy (how climate risks and opportunities affect the business model, strategy, and financial planning, including scenario analysis), risk management (how climate risks are identified, assessed, prioritised, and monitored), and metrics and targets (the quantitative measures the company uses to track performance, including GHG emissions per the GHG Protocol).

The ISSB explicitly built IFRS S2 to incorporate and supersede TCFD (Task Force on Climate-related Financial Disclosures) recommendations, which means that companies that had already structured their reporting around TCFD have a clear migration path. The ISSB also worked to ensure compatibility with GRI, recognising that many companies use both frameworks and that requiring completely duplicative disclosures would create unnecessary compliance burden.

Singapore's adoption of IFRS S2 through the SGX framework means that Singapore is among the early movers globally in mandating ISSB-aligned climate disclosure. This positions Singapore listed companies at the leading edge of international investor expectations and aligns their reporting with the standards increasingly required by regulators in the EU, UK, Australia, and other major markets.

What Singapore Companies Must Actually Produce

The practical answer to "what do I need to produce?" depends entirely on whether you are a listed or non-listed company.

For SGX-listed companies, the mandatory deliverable from FY2025 is an Annual Sustainability Report that complies with IFRS S1 and IFRS S2. This means the report must cover all four IFRS S2 pillars: a governance section describing how climate oversight works at board and management level; a strategy section explaining how climate scenarios have been assessed and how they affect the business model and financial planning; a risk management section describing how climate risks are identified, assessed, and integrated into the company's overall risk process; and a metrics and targets section that includes Scope 1 and Scope 2 GHG emissions calculated using the GHG Protocol, along with any relevant climate targets and performance against them.

Many listed companies choose to report GRI 305 data alongside their IFRS S2 disclosures. This is not required but is common practice for companies that want to satisfy both international investors (who are familiar with GRI) and SGX requirements simultaneously. Where GRI 305 disclosures are made, the same underlying emissions data powers both, since both standards use the GHG Protocol as the accounting basis.

For non-listed companies, there is currently no mandatory sustainability reporting framework in Singapore. However, this does not mean reporting is irrelevant. EnterpriseSG's SME sustainability programme — which offers up to 50% grant support from April 2026 through appointed providers — is built around a structured GHG disclosure process that aligns with GHG Protocol methodology and ISO 14064-1. Companies participating in the programme produce a sustainability report that covers their GHG footprint in a format that is compatible with both GRI 305 and IFRS S2, giving them a defensible evidence base if they are later required to report formally or if their customers (particularly large listed companies managing Scope 3 disclosures) request verified data.

GRI 305 vs IFRS S2 Emissions Disclosure: The Comparison

Because both GRI 305 and IFRS S2 use the GHG Protocol as their accounting basis, the underlying emissions measurement is the same. The difference lies in what surrounds the numbers and how those numbers are presented.

GRI 305-1 requires disclosure of direct (Scope 1) GHG emissions, with breakdowns by gas type and, where applicable, by country or business unit. GRI 305-2 requires energy-indirect (Scope 2) emissions, with a distinction between location-based and market-based calculation methods. GRI 305-3 requires other indirect (Scope 3) emissions across all 15 GHG Protocol categories, with a clear explanation of which categories are included and why others are excluded. GRI 305-4 requires GHG intensity — emissions per unit of a relevant business metric, which might be revenue, production volume, headcount, or floor area depending on the sector. GRI 305-5 requires disclosure of GHG emissions reductions achieved as a result of specific initiatives, with a clear base year and methodology for measuring the reduction.

IFRS S2 paragraph 29 covers the same substantive content for Scope 1 and Scope 2 — and the specific calculation requirements are nearly identical to GRI 305-1 and 305-2 because both draw from the same source standard. Where IFRS S2 differs structurally is that the emissions data sits within a much broader strategic and financial context. IFRS S2 requires the company to explain how climate scenario analysis has been conducted, how physical and transition climate risks have been assessed, how those risks feed into the financial planning process, and how the board and management are accountable for climate performance. This financial integration — tying emissions data to strategy, risk, and governance — is not part of the GRI 305 scope.

In practical terms: the spreadsheet of emissions data you build for GRI 305 can be imported directly into your IFRS S2 metrics and targets section without modification. But you cannot produce an IFRS S2-compliant report from GRI 305 data alone. You need three additional pillars of narrative and analytical disclosure that GRI does not require.

A Practical Guide for Singapore Companies

If you are a Singapore listed company starting your IFRS S2 journey, the recommended sequence is to begin with the mandatory core and then layer in GRI if your investor or customer base expects it. Start with a materiality assessment to determine which climate risks and opportunities are material to your specific business. Then build the four pillars: document your board climate governance structure; conduct at least a qualitative climate scenario analysis (physical and transition risks under recognised scenarios such as IEA or IPCC pathways); map how climate risks are assessed and escalated in your risk management process; and measure your Scope 1 and Scope 2 emissions using the GHG Protocol.

Once the IFRS S2 core is in place, adding GRI 305 reporting is relatively straightforward because the emissions data is already collected. GRI 305-3 (Scope 3) and GRI 305-4 (intensity) are the areas where GRI adds the most value beyond IFRS S2's current mandatory requirements. Companies with international investors, supply chain customers in Europe, or ambitions to attract foreign institutional capital will find that GRI 305 reporting alongside IFRS S2 satisfies a broader range of expectations without requiring duplicate measurement effort.

If you are a non-listed Singapore company, you are not currently subject to any mandatory reporting obligation. However, the trajectory is clear: Scope 3 reporting by listed companies requires data from their supply chains, meaning that non-listed suppliers will increasingly face informal or contractual requirements to disclose their emissions. Beginning with a GHG Protocol inventory — ideally aligned with ISO 14064-1 methodology and structured in a format compatible with GRI 305 or IFRS S2 — puts you ahead of that curve and positions you to access EnterpriseSG's grant support.

The underlying message across both categories is the same: the emissions measurement methodology is consistent (GHG Protocol) regardless of which reporting standard you use. The investment in getting your data right — boundary setting, activity data collection, emission factor selection, quality review — is not wasted effort that needs to be repeated when frameworks change. It is the reusable foundation that powers compliance across GRI, IFRS S2, and SGX requirements simultaneously.