Scope 1, 2 & 3 GHG Inventory Thailand (TGO)

A greenhouse-gas (GHG) inventory is the foundation of every credible climate programme — it is the number behind your net-zero target, your CDP score, your IFRS S2 disclosure, and increasingly your customers’ supply-chain requirements. For Thai companies, building one that is GHG Protocol and TGO-aligned is now table stakes for SET ESG performance and export competitiveness.

Scope 1, 2 and 3 — what they mean

• Scope 1 — direct emissions from sources you own or control: fuel combustion, company vehicles, on-site processes.
• Scope 2 — indirect emissions from the electricity, steam, heating and cooling you purchase.
• Scope 3 — value-chain emissions: everything else, from purchased goods and business travel to the use of your products. Usually the largest share — and the hardest to measure.

Why Thai companies need a GHG inventory now

Several forces converge: the move to FTSE Russell ESG Scores in 2026 rewards quantified climate disclosure; IFRS S2 requires Scope 1, 2 and (where material) Scope 3 reporting; the Thailand Greenhouse Gas Management Organization (TGO) sets the local CFO/CFP standards; science-based targets need a verified baseline; and the EU’s CBAM is already pricing the carbon in exported goods. One robust inventory feeds all of them.

GHG Protocol and TGO alignment

A defensible inventory follows the GHG Protocol Corporate Standard for boundaries and accounting, and aligns with TGO guidance and emission factors for the Thai context. Getting both right means your numbers are accepted by international raters and by Thai regulators alike.

How to build one

• Set organisational and operational boundaries (equity share or control).
• Collect activity data — fuel, electricity, travel, purchased goods — across sites.
• Apply emission factors (TGO, IPCC, supplier-specific) to convert activity to tCO₂e.
• Screen and prioritise Scope 3 categories by relevance and size.
• Quality-check and verify, then document the methodology for audit.

Disclosing it clearly, in both languages

An inventory only earns recognition once it is reported — and for SET-listed companies that means Thai and English, consistent across the One Report, sustainability report and CDP response. Othello International pairs GHG inventory advisory with ISO 17100-certified bilingual translation, so your climate data is accurate and investor-ready in both languages. Talk to our ESG advisory team to get started.

Getting the boundary right before you count anything

The most consequential decisions in a GHG inventory are made before a single tonne is counted. Setting the organisational boundary determines which entities’ emissions belong to the company — under the equity-share approach you count emissions in proportion to ownership, while under the control approach (financial or operational) you count entities you control in full. For Thai groups with joint ventures, associates and complex holding structures, this choice materially changes the reported footprint and must be applied consistently year on year.

The operational boundary then defines which sources fall into Scope 1, 2 and 3. Getting this documented and repeatable is what allows a company to compare against its baseline, defend the numbers under assurance, and avoid the common trap of a footprint that appears to change year on year only because the boundary quietly shifted. A clearly recorded boundary and base year is the backbone of a credible inventory.

Why Scope 3 is where Thai exporters win or lose

For most Thai companies — and especially exporters — Scope 3 dwarfs Scopes 1 and 2 combined. It is also where customer pressure now concentrates: multinational buyers pursuing their own net-zero targets increasingly ask suppliers for product- and category-level emissions data, and carbon border measures put a price on the embedded carbon of exported goods. A company that cannot quantify its value-chain emissions is increasingly at a commercial disadvantage, not just a disclosure one.

The pragmatic approach is to screen all fifteen Scope 3 categories, identify the few that dominate — typically purchased goods and services, upstream transport, and use of sold products — and invest measurement effort there first. Early-stage inventories legitimately rely on spend-based or average-data estimates; the maturity path is to move the largest categories toward supplier-specific and activity-based data over time. Disclosing which categories are included, which are excluded and why, and what data quality underpins each, is itself a mark of credibility that raters reward.

Choosing emission factors for the Thai context

Emission factors convert activity data into tonnes of CO₂-equivalent, and the choice of factor set matters for both accuracy and acceptance. For Scope 2 in particular, the Thai grid emission factor published through TGO reflects the local generation mix and is expected by domestic reviewers, whereas international raters look for transparency about which factor and which accounting method — location-based or market-based — was used. Aligning to TGO factors and GHG Protocol conventions, and stating clearly which sources you drew on, keeps the inventory defensible on both sides.

Verification and the bilingual disclosure trail

Independent verification turns an internal estimate into an assured figure investors can rely on, and it is fast becoming an expectation rather than a differentiator. But verification is only as useful as the disclosure that carries it — and for SET-listed companies that disclosure lives in two languages. The same inventory feeds the Thai-language 56-1 One Report and the English sustainability report, CDP response and index-provider submissions. When the methodology note, boundary description or emissions table is translated inconsistently, the English figures that FTSE Russell and MSCI assess can diverge from the audited Thai record — an avoidable risk that can depress a score or trigger rater queries.

Technical GHG vocabulary — base year, boundary, emission factor, market-based, removal, tCO₂e — carries precise meaning that a generalist translation can blur. Keeping the Thai and English versions of the inventory strictly aligned, within an ISO 17100 quality process staffed by reviewers who understand the GHG Protocol, is what ensures the number that took months to build is read the same way by every audience. That is the specific gap Othello International’s bilingual ESG practice is built to close.

Common pitfalls in a first inventory

• Shifting boundaries. Changing what is counted without restating the base year makes trends meaningless and undermines assurance.
• Ignoring Scope 3. Reporting only Scopes 1 and 2 leaves out the majority of most Thai companies’ footprint — and the part customers care about.
• Undocumented methodology. If factors, sources and assumptions are not written down, the inventory cannot survive audit or be reproduced next year.
• Language drift. Letting the Thai and English versions diverge quietly turns one dataset into two conflicting records.

A GHG inventory built on a clear boundary, honest Scope 3 screening, appropriate factors, independent verification and disciplined bilingual disclosure becomes an asset the whole climate programme rests on. To build or strengthen yours, explore our ESG advisory services or contact our team.

Related ESG guides

• Double Materiality Assessment, Explained for Thai Issuers
• SET Moves to FTSE Russell ESG Scores in 2026: What SET-Listed Boards Must Do
• GRI vs SASB vs IFRS S1/S2: ESG Reporting Frameworks Explained (2026)
• 56-1 One Report Deadline 2026: Thailand Filing Dates & Bilingual Requirements
• Carbon Credits in Thailand 2026: T-VER, Premium T-VER and What Corporates Need to Know

Related Othello services

• GHG Inventory (Scope 1, 2, 3)
• GHG Inventory & TGO
• Science-Based Targets (SBTi)

📘 Free resource: Explore The FTSE 2026 Playbook Library — Othello’s ESG disclosure playbook plus focused editions for Thai banks, energy, property, healthcare, technology and more.

Related services from Othello International

Othello International is a Bangkok-based bilingual (EN↔TH) technical translation and ESG advisory firm. Related specialist services:

• GHG inventory — Scope 1/2/3, TGO-aligned
• ESG disclosure translation — IFRS S2, GRI, FTSE-ready
• climate & IFRS S2 disclosure — TCFD four-pillar