Scope 1 emissions — definition,
categories, and calculation.
Scope 1 emissions are direct greenhouse gas emissions from sources owned or controlled by the reporting company. Under the GHG Protocol Corporate Standard, Scope 1 is the first and most foundational inventory boundary — it captures what the company directly releases into the atmosphere from its own operations.
For manufacturing companies, Scope 1 is dominated by fuel combustion in boilers, furnaces, and fleet — with fugitive emissions from refrigeration systems adding a significant GWP-weighted contribution that is frequently underestimated. Sustaineve calculates all four Scope 1 categories using IPCC 2006 & 2019 emission factors with AR5 GWP values — every figure traceable, every source cited.
The Four Scope 1 Categories
GHG Protocol defines four Scope 1 categories.
Sustaineve handles all four.
Stationary Combustion
GHG emissions from combustion of fuels in stationary equipment — boilers, furnaces, ovens, turbines, generators at fixed plant locations.
Manufacturing examples
- Coal boilers for process heat
- Natural gas furnaces
- Diesel backup generators
- HFO boilers in textile dyeing
- LPG process burners
Typically the highest Scope 1 source in textile, steel, and cement manufacturing — coal and gas combustion for process heat.
Selected IPCC CO₂ Emission Factors
CH₄ + N₂O factors also applied. AR5 GWP-weighted.
Mobile Combustion
GHG emissions from combustion of fuels in company-owned or company-controlled mobile sources — vehicles, forklifts, bulldozers, trains, ships.
Manufacturing examples
- Company vehicles (cars, trucks)
- Diesel forklifts and material handlers
- On-site heavy equipment
- Delivery and logistics fleet
Moderate Scope 1 contributor. Diesel fleet is the dominant source.
Selected IPCC CO₂ Emission Factors
CH₄ + N₂O factors also applied. AR5 GWP-weighted.
Fugitive Emissions
Intentional and unintentional releases of GHGs from equipment — refrigerant leaks from HVAC and process cooling systems, SF₆ from electrical equipment, methane from gas distribution.
Manufacturing examples
- Refrigerant leaks (HFCs, HCFCs)
- SF₆ from high-voltage switchgear
- Methane from gas pipeline leaks
- Process cooling system losses
Often under-reported. Textile manufacturing with large dyeing and finishing areas has significant refrigeration plant. High GWP per kg of refrigerant means small leaks have large CO₂e impact.
Selected IPCC CO₂ Emission Factors
CH₄ + N₂O factors also applied. AR5 GWP-weighted.
Process Emissions
GHG emissions directly from industrial chemical and physical manufacturing processes — not from combustion. Relevant for cement (calcination), chemicals, metal production, and certain textile finishing processes.
Manufacturing examples
- Cement clinker production (CO₂ from calcination)
- Ammonia and fertiliser production
- Aluminium smelting (PFCs)
- Chemical synthesis releasing CO₂ or N₂O
High relevance for cement, chemicals, steel. Lower for textile manufacturing unless chemical finishing processes are involved. Process-specific factors apply — industry-dependent.
Emission Factors
Process-specific. Depends on manufacturing process type. IPCC Vol.3 and industry-specific guidance applies.
IPCC factors referenceCalculation Method
How Scope 1 tCO₂e is calculated.
The calculation is consistent across all Scope 1 categories — activity data multiplied by IPCC emission factors, GWP-weighted across all gases.
Scope 1 Calculation — Natural Gas Boiler Example
IPCC 2019 · GHG Protocol · AR5 GWP-100
Inputs
Natural gas consumed, Plant A, FY 2024–25
IPCC 2019 Table 2.2 — natural gas
IPCC 2006 Table 2.2 — stationary combustion
IPCC 2006 Table 2.2 — stationary combustion
IPCC AR5 100-year GWP
IPCC AR5 100-year GWP
Calculation steps
CO₂
4,280 GJ × 55.2 kgCO₂/GJ = 236,256 kgCO₂ = 236.3 tCO₂
CH₄
4,280 GJ × 1.1 g/GJ = 4,708 gCH₄ × 27.9 GWP = 131,353 gCO₂e = 0.13 tCO₂e
N₂O
4,280 GJ × 0.1 g/GJ = 428 gN₂O × 273 GWP = 116,844 gCO₂e = 0.12 tCO₂e
Total Scope 1 — Natural Gas Plant A
236.4 tCO₂e
Audit ID: SE-2425-A-0047 · IPCC 2019 · AR5 GWP
FAQ
Scope 1 emissions — common questions.
What are Scope 1 emissions?
Scope 1 emissions are direct greenhouse gas emissions from sources owned or controlled by the reporting company. Under the GHG Protocol Corporate Standard, Scope 1 is divided into four categories: stationary combustion (boilers, furnaces, generators), mobile combustion (company vehicles), fugitive emissions (refrigerant leaks, SF₆), and process emissions (industrial chemical reactions). All Scope 1 is measured in tCO₂e.
What IPCC emission factors are used for Scope 1 stationary combustion?
Sustaineve uses default emission factors from IPCC 2006 Guidelines Vol.2 Ch.2 Table 2.2, updated by 2019 Refinements where applicable. Examples: natural gas CO₂ EF = 55.2 kgCO₂/GJ, coal (bituminous) = 94.6 kgCO₂/GJ, diesel = 74.1 kgCO₂/GJ. CH₄ and N₂O factors are also applied from the same table, GWP-weighted using IPCC AR5 values.
How is Scope 1 calculated in tCO₂e?
Scope 1 tCO₂e = Activity Data (GJ) × Emission Factor (kgGas/GJ) × GWP, summed for CO₂, CH₄, and N₂O per source, then totalled across all Scope 1 categories. GWP values are from IPCC AR5 100-year: CO₂ = 1, CH₄ = 27.9 (fossil), N₂O = 273.
What is the difference between Scope 1 and Scope 2?
Scope 1 emissions are direct — from sources the company owns or controls. Scope 2 emissions are indirect — from purchased electricity, steam, heat, or cooling generated externally but consumed by the company. Both are mandatory under BRSR and GHG Protocol reporting.
Are process emissions included in Scope 1?
Yes. Process emissions from industrial chemical or physical reactions are Scope 1 category 4 under GHG Protocol. They are relevant for cement, chemicals, and certain metal manufacturing operations. Sustaineve includes process emissions as a Scope 1 input category.
Scope 1 calculation — exact, traceable, auditable
See your Scope 1 inventory calculated.
All four categories. IPCC factors cited. Full audit trail. 30-minute demo.