Why Carbon Accounting Matters
With the 2026 ESG disclosure mandate roadmap finalized, carbon emission calculation and management has become an essential capability for all businesses. SME suppliers of large corporations must respond to Scope 3 data requests from their customers.
The government declared "eliminating carbon illiteracy" and announced focused support for supply chain companies' carbon emission calculations. This guide provides step-by-step instructions for SMEs to practically build carbon accounting systems.
Carbon Accounting Fundamentals
Greenhouse Gas Emission Scopes
Scope 1: Direct Emissions
Scope 2: Energy Indirect Emissions
Scope 3: Other Indirect Emissions (Reference)
Major Greenhouse Gases
| Gas | Formula | GWP | Main Sources |
|-----|---------|-----|-------------|
| Carbon Dioxide | CO₂ | 1 | Fossil fuel combustion |
| Methane | CH₄ | 28 | Waste, agriculture |
| Nitrous Oxide | N₂O | 265 | Fertilizers, combustion |
| HFCs | HFCs | 1,300~14,800 | Refrigerants, AC |
Step-by-Step Implementation Guide
Step 1: Set Organizational Boundaries (1 week)
The first step is deciding what falls within your calculation scope.
Approaches:
Included Targets:
Step 2: Identify Emission Sources (1-2 weeks)
Scope 1 Source Inventory:
| Source | Fuel/Material | Data Source |
|--------|--------------|------------|
| Boiler | LNG, diesel | Gas/fuel bills |
| Vehicles | Gasoline, diesel | Fuel card records |
| Emergency generator | Diesel | Purchase slips |
| AC/Refrigerators | HFC refrigerant | Recharge/repair logs |
| Welding/Cutting | Acetylene, LPG | Purchase slips |
Scope 2 Sources:
| Source | Data Source |
|--------|-----------|
| Electricity | Electricity bills |
| Steam purchase | Heat supply bills |
| District heating/cooling | Utility bills |
Step 3: Collect Activity Data (2-4 weeks)
Collection Items and Units:
Data Collection Tips:
Step 4: Calculate Emissions (1-2 weeks)
Basic Calculation Formula:
Emissions (tCO₂eq) = Activity Data × Emission Factor × GWP
Key Emission Factors (2026 Standards):
| Fuel/Energy | Emission Factor | Unit |
|------------|----------------|------|
| Electricity (Korea) | 0.4594 | kgCO₂/kWh |
| LNG | 2.176 | kgCO₂/Nm³ |
| Diesel | 2.582 | kgCO₂/liter |
| Gasoline | 2.168 | kgCO₂/liter |
| LPG | 1.613 | kgCO₂/liter |
| Kerosene | 2.441 | kgCO₂/liter |
Calculation Example (SME manufacturer, 10B KRW annual revenue):
Step 5: Build Reporting Framework (2-4 weeks)
Required Report Components:
Free and Low-Cost Calculation Tools
| Tool | Cost | Features |
|------|------|----------|
| ME Carbon Neutrality Platform | Free | Korea SME specialized |
| GHG Protocol Calculator | Free | Global standard |
| EcoSquare | 100-300K KRW/mo | SaaS, auto reports |
| Net Zero Platform | 200-500K KRW/mo | Supply chain data integration |
Common Mistakes and Precautions
KITIM ESG Data Consulting
KITIM professionally supports SMEs in building carbon accounting systems.