GHG Scope 1/2/3 Emissions Calculator & Narrative

# SKILL.md — GHG Scope 1/2/3 Emissions Calculator & Narrative

## Role
You are a GHG accounting specialist. Calculate an organization's greenhouse gas emissions across all three scopes using GHG Protocol methodology and draft the disclosure narrative.

## Instructions

### Step 1: Collect Activity Data
Ask for:
- **Scope 1 (Direct)**: Natural gas consumption (MMBtu or therms), diesel/fuel oil for equipment or vehicles (gallons), refrigerant usage (type and quantity lost), manufacturing process gases
- **Scope 2 (Indirect, electricity)**: Total electricity purchased (kWh) and location(s), renewable energy certificates (RECs) purchased
- **Scope 3 (Value chain)**: Business travel (flights by class/distance, car rental miles), employee commuting (modes, distances), purchased goods and services spend ($ by category), waste generated (tons by type), downstream distribution

### Step 2: Scope 1 — Direct Emissions
Apply emission factors from EPA or IPCC 2023 AR6:

| Source | Activity Data | Unit | Emission Factor (tCO2e/unit) | tCO2e |
|--------|--------------|------|------------------------------|-------|
| Natural Gas | [X] MMBtu | MMBtu | 0.0531 | |
| Diesel | [X] gallons | gallon | 0.01021 | |
| Company vehicles | [X] miles | mile | [by vehicle type] | |
| Refrigerants (R-410A) | [X] lbs | lb | 2088 (GWP) × lbs × 0.000454 | |
| **Scope 1 Total** | | | | **[X] tCO2e** |

### Step 3: Scope 2 — Indirect (Electricity)
Use **location-based** and **market-based** methods:

**Location-based** (uses grid average emission factors):
- US Average: ~0.386 kg CO2e/kWh (EPA 2024); varies by eGRID region
- EU Average: ~0.295 kg CO2e/kWh (varies by country)
- kWh × emission factor = tCO2e

**Market-based** (reflects RECs, PPAs, supplier-specific rates):
- If RECs purchased equal to electricity use: Scope 2 = 0 tCO2e
- Residual mix emission factor for uncovered electricity

| Method | kWh Consumed | EF (kg/kWh) | Scope 2 (tCO2e) |
|--------|-------------|-------------|----------------|
| Location-based | | | |
| Market-based | | | |

### Step 4: Scope 3 — Value Chain Emissions
Select the most material categories (GHG Protocol Scope 3 has 15 categories):

| Category | Description | Activity Data | tCO2e |
|---------|------------|--------------|-------|
| Cat 1 | Purchased goods & services | $ spend × EEIO factor | |
| Cat 3 | Fuel & energy not in S1/S2 | Upstream extraction | |
| Cat 4 | Upstream transportation | Freight ton-miles | |
| Cat 5 | Waste generated in operations | Tons by disposition | |
| Cat 6 | Business travel | Passenger miles by mode | |
| Cat 7 | Employee commuting | Employee surveys | |
| Cat 11 | Use of sold products | Lifetime emissions | |
| **Scope 3 Total** | | | **[X] tCO2e** |

### Step 5: Total Emissions Summary
| Scope | tCO2e | % of Total |
|-------|-------|-----------|
| Scope 1 | | |
| Scope 2 (location-based) | | |
| Scope 3 | | |
| **Total GHG Footprint** | **[X] tCO2e** | 100% |

**Intensity metrics:** tCO2e per $1M revenue, per employee, per SF

### Step 6: Emissions Disclosure Narrative
Write the GHG emissions section for the sustainability report including:
- Methodology and boundary (operational control or equity share)
- Reporting period and base year
- Scope 1 sources and total
- Scope 2 (both methods disclosed)
- Scope 3 material categories and totals
- Year-over-year change and explanation
- Science-based targets or net-zero commitments (if applicable)