Step 1: What is a GHG inventory?
On This Page (10 sections)
This is step 1 of 7 in Build your GHG inventory. Next: Step 2: Set your organisational boundaries.
A greenhouse gas (GHG) inventory is a list of all the sources of greenhouse gases that your organisation is responsible for, with the emissions of each source over one reporting period. The reporting period is usually your financial year. The emissions are in tonnes of carbon dioxide equivalent (tCO₂e).
What an inventory contains
A complete inventory answers 5 questions:
| Question | Where it is decided |
|---|---|
| Which parts of the group are included? | Step 2: Organisational boundaries |
| Which types of emissions are included? | Step 3: Operational boundaries |
| Which activities cause emissions? | Step 4: Emission sources |
| How much of each activity happened? | Step 5: Data collection |
| How many tonnes of CO₂e does that make? | Step 6: Emissions calculation |
The result is a table of sources, grouped by facility and by scope, with a total for each scope. The GHG Protocol also asks you to show each gas separately and to keep biogenic CO₂ (from burning biomass) outside the 3 scopes.
Example. A food manufacturer with one factory and a delivery fleet might list these sources:
| Source | Scope | Activity data |
|---|---|---|
| Gas-fired boiler | Scope 1 | m³ of natural gas |
| Delivery lorries | Scope 1 | litres of diesel |
| Chiller refrigerant top-ups | Scope 1 | kg of refrigerant |
| Grid electricity | Scope 2 | kWh |
| Flour and packaging purchases | Scope 3, category 1 | tonnes or RM spent |
| Staff flights | Scope 3, category 6 | passenger-km |
| Staff commuting | Scope 3, category 7 | survey of distance and mode |
Why you need one
To report. Listed companies in Malaysia report Scope 1, Scope 2 and some Scope 3 emissions under Bursa Malaysia's rules and the National Sustainability Reporting Framework (NSRF). Climate reporting rules in Malaysia and worldwide gives the dates.
To answer customers. Large companies must report the emissions in their value chain. They ask their suppliers for data. A supplier with an inventory can answer with real figures.
To reduce emissions and costs. You cannot manage what you have not measured. The inventory shows which sites and activities cause the most emissions. These are often the same places where you spend the most on energy.
To set targets. A reduction target needs a base year with a reliable inventory. Without it, you cannot show progress.
Decide 3 things before you start
1. Your purpose
Write down why you are building the inventory. The purpose affects later choices. For example, a company that reports under IFRS S2 must consider all 15 Scope 3 categories. A company that only answers a customer's questionnaire may start with Scope 1 and Scope 2.
2. Your audience
List who will use the inventory: the board, investors, regulators, customers or banks. Each group may expect a different level of detail and a different standard. Ask them early.
3. Your team
Choose one person who owns the inventory. Then name a contact for each type of data:
- Finance, for the group structure, ownership shares and spend data
- Facilities or operations, for electricity, fuel and refrigerant records
- Procurement and logistics, for supplier and transport data
- Human resources, for staff numbers and commuting surveys
Agree on deadlines with each contact. Data collection is usually the slowest part of the first inventory.
Your reporting period
Use the same period as your financial statements. IFRS S1 requires sustainability disclosures, including emissions, to cover the same reporting period as the financial statements. IFRS S2 lets you use value chain data for a different period in some cases, for example a supplier's calendar year. If you do, record the difference.
Check your progress
Before you go to step 2, make sure that you have:
- A written purpose and a list of users
- A reporting period
- An owner and a contact for each data area
In Carbon GPT
The Dashboard shows your inventory as you build it: total emissions for each scope, the largest categories and the monthly trend.
Sources
- GHG Protocol Corporate Standard, chapters 2 and 9
- IFRS S2 Climate-related Disclosures
- IFRS S1 General Requirements, paragraph 64 (reporting period)
- IFRS: Transition Implementation Group, question 6 (reporting period alignment, September 2024)
- Securities Commission Malaysia: National Sustainability Reporting Framework
