Scope 1 emissions
Direct greenhouse gas emissions from sources owned or controlled by a reporting organisation, such as boilers, furnaces, vehicles and process emissions.
The GHG Protocol Corporate Standard divides an organisation's footprint into three scopes. Scope 1 covers emissions released directly by assets it owns or operationally controls:
- Stationary combustion: gas boilers, coal-fired units, diesel generators, CHP plants
- Mobile combustion: company cars, trucks, ships and aircraft
- Process emissions: calcination in cement (about 0.5 t CO2 per tonne of clinker from limestone alone), steel blast furnaces, chemical reactions
- Fugitive emissions: refrigerant leaks, methane leaks from gas infrastructure, SF6 from switchgear
Typical combustion emission factors: natural gas 56.1 kg CO2/GJ (about 0.20 kg/kWh of fuel, net calorific basis), diesel 74.1 kg/GJ, bituminous coal 94.6 kg/GJ (IPCC 2006 Guidelines defaults). For power generators Scope 1 dominates the footprint and is the quantity surrendered under compliance schemes such as the EU ETS. Scope 1 is reported in CO2e, with the GWP set (AR5 or AR6) disclosed.
Related terms
All terms →- Scope 2 emissions
Indirect emissions from the generation of purchased electricity, steam, heat or cooling consumed by a reporting organisation.
- Scope 3 emissions
All other indirect emissions in an organisation’s value chain, upstream and downstream, not covered by Scope 1 or Scope 2.
- CO2e (CO2 equivalent)
A common unit that expresses emissions of different greenhouse gases as the mass of CO2 that would cause the same warming over a chosen time horizon.
- Emissions Trading System (ETS)
A cap-and-trade market in which a regulator caps total emissions, issues tradable allowances, and requires covered installations to surrender one allowance per tonne emitted.
- Global warming potential (GWP)
The time-integrated radiative forcing of one kilogram of a gas relative to one kilogram of CO2, over a stated period such as 20 or 100 years.