Carbon Footprint Demystified: 3 Key Steps to Start Measuring Your Carbon Footprint
For many businesses in Singapore, the process of calculating Scope 1, 2, and 3 emissions under standards like ISO 14064-1 or the GHG Protocol can feel overwhelming but it doesn’t have to be.
Here is a simplified breakdown of the core steps every company must take before calculating its Greenhouse Gas (GHG) emissions inventory:
Step 1: Define Your Organizational Boundary
Before measuring emissions, decide which entities, projects, or assets are included in your company’s carbon footprint. This is based on either:
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Operational Control – If you run it, you report 100% of the emissions.
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Financial Control – If you financially control it, you report the emissions.
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Equity Share – Report emissions based on your % ownership.
The Goal is to set a clear, consistent boundary for all emissions reporting.
Step 2: Establish Your Reporting Boundary
Next, list all emission sources inside your organizational boundary and group them into:
Scope 1 (Direct Emissions) – From sources you own or control (e.g., company boilers, business vehicles, refrigerant leaks). Scope 2 (Indirect Energy Emissions) – From purchased electricity or energy.
Scope 3 (Other Indirect Emissions) – From your value chain (e.g., business flights, purchased goods, waste, logistics, etc.).
The Goal is to capture the complete lifecycle of your company’s climate impact.
Step 3: Ensure Accuracy with a Quality Management Framework (QMF)
Now that your emissions map is set, it’s time to measure with confidence:
Use the formula i.e. Activity Data x Emission Factor
Select a Base Year to track reductions over time
Develop a Monitoring Plan to ensure reliable and consistent data
Review and minimize uncertainty through better tools and controls
The Goal is to build a robust, auditable GHG dataset aligned with ISO 14064-1 requirements.
Understanding GHG Emission Categories: The Essential Guide for Businesses in Singapore
If you are starting your journey toward ISO 14064-1 certification, carbon accounting, or ESG reporting, understanding the six categories of GHG emissions is a crucial first step.
These categories provide a clear, standardized framework for capturing both direct and indirect emissions helping your organization build a complete and compliant carbon footprint inventory.
Group 1: Direct Emissions (Category 1)
These are emissions your company directly controls — from assets you own or operate.
Category 1 – Direct GHG Emissions & Removals
Examples include:
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Fuel burned in company boilers or vehicles
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Refrigerant leakage (fugitive emissions)
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Industrial process emissions
Mandatory to quantify and report under ISO 14064-1.
Group 2: Indirect Emissions (Categories 2–6)
Emissions that occur outside your business but are driven by your operations. These are just as important for full-value chain reporting.
Category 2 – Imported Energy
Emissions from electricity, steam, or heat your business purchases.
Category 3 – Transportation
Pollution from business travel, employee commuting, and freight you pay for (but do not control).
Category 4 – Products Used by Organization
Upstream emissions from purchased goods, materials, and capital assets used in your operations.
Category 5 – Use of Products from Organization
Downstream emissions when your customer uses or disposes of your product.
Category 6 – Other Sources
Investment-related impacts or other indirect emissions not captured elsewhere.
These categories are only mandatory if they’re deemed “significant” — a core concept in ISO 14064-1.
Quick Takeaway
Category 1 = Direct, Mandatory
Categories 2–6 = Indirect, Track if Significant
Understanding and reporting across all six GHG categories is not just a compliance requirement. It is a strategic advantage for carbon reduction planning, ESG disclosure, and meeting Singapore’s decarbonisation targets.
What Does “Significant” Really Mean in Carbon Reporting?
When building a GHG inventory under ISO 14064-1, one of the most crucial question you will ask decisions: Which indirect emissions are “significant” ?
The answer isn’t set by any government. It is defined by YOU, the reporting company.
Because you can’t measure every emission source, “significant” acts as your internal filter. It helps focus carbon measurement resources where they have the most impact — whether that is regulatory compliance, investor trust, or actual decarbonization results.
4 Key Factors for Determining Significance
When evaluating indirect emissions (Categories 2–6), companies assess:
Simplified Factor Technical Term Key Question to Ask
Size & Impact Magnitude / Volume Does this source represent a large % of total emissions?
Control & Influence Level of Influence Can we impact or reduce this source?
Regulatory or Financial Risk Risk Assessment Are we required to report this? Could omission create risk?
Data Availability Access to Information/Accuracy an we get reliable, auditable data?
Any excluded source must be justified and documented in the GHG report.
To decide where to focus carbon reporting efforts, a cookie manufacturer reviews its indirect emissions:
Emission Source Why It Matters Significant?
Purchased electricity Very high volume, full company control Yes
Emissions from flour supplier Buyer requires reporting, key partnership Yes
Employee commuting Low volume, low influence on behavior Depends on reporting goals
Result: ABC Cookie Pte Ltd invests in accurate data collection for electricity and raw materials and sidesteps low impact sources unless specifically required.
Why This Matters
Defining “significant” emission sources enables smarter carbon reporting, stronger ESG performance, and better resource allocation especially crucial for companies preparing for ISO 14064-1 verification, carbon tax compliance, or net zero strategy.
How Accurate Is Your Carbon Emissions Report? Understanding GHG Uncertainty in ISO 14064 Reporting
When calculating greenhouse gas (GHG) emissions, every organization—whether SME or MNC—faces one critical question:
How certain are we that our emissions number is accurate?
The answer lies in understanding uncertainty—the unavoidable doubt in every carbon footprint calculation, especially under ISO 14064-1 and the GHG Protocol.
The Core Calculation Behind Emissions
Every GHG emissions calculation is based on a simple formula:
Emissions = Activity Data × Emission Factor
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Activity Data (AD): e.g., liters of diesel fuel used
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Emission Factor (EF): e.g., kg of CO₂ emitted per liter of diesel
Both values come with uncertainty. And when you multiply them together, those uncertainties stack—you can’t cancel them out.
Why "Doubt Always Stacks Up" – The Compounding Rule
The rule at the heart of emissions uncertainty is:
Final emissions uncertainty is always greater than the largest input uncertainty.
This is known as the compounded uncertainty principle.
To combine uncertainties for reporting, ISO 14064 uses a statistical method called the sum of squares.
Simple Example: Diesel Use in a Factory
Let’s say your company reports:
Parameter Value Uncertainty (±)
Activity Data (AD) 10,000 L diesel 5%
Emission Factor (EF) 2.68 kg CO₂/L 10%
Through compounded uncertainty:
Total uncertainty ≈ √(5² + 10²)% = 11.18%
So, if reported emissions are 26.8 tonnes CO₂e, the real figure lies within ±11.18% of that number.
This tells your sustainability team exactly where the biggest impact lies:
Fixing the Emission Factor quality has the greatest potential to reduce reporting uncertainty.
A Simple Analogy
Think of it like measuring the height of a cloud using two imperfect tools—like a thermometer and barometer. Each tool has its own error margin. When you combine them in an equation, your final cloud height estimate becomes less precise, not more.
That is how uncertainty works in carbon accounting.
Whether you’re preparing for ISO 14064 verification, responding to ESG reporting requirements, or aiming for carbon neutrality, understanding uncertainty helps you:
✅ Identify weak points in data quality
✅ Build auditor-ready emission reports
✅ Prioritise smarter sustainability investments
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