CO2 information – Calculation method
Why calculate greenhouse gas emissions due to travel?
How can I reduce my carbon footprint by using the RATP network?
How do you calculate the distances travelled?
How do we calculate CO2 emissions?
Regulatory report on greenhouse gas emissions
The Grenelle 2 law (n°2010-788 of 12 July 2010, article 75) requires public service companies with more than 250 employees to conduct an inventory of greenhouse gas emissions. This regulatory report covers the following emissions:
- “Direct” emissions: for RATP, this consists mainly of the combustion of bus fuel and refrigerant leakage from heating and cooling systems.
- “Indirect” emissions pertaining to energy: emissions associated with the consumption of electricity, heat and vapour.
For RATP, the emissions falling within this scope are estimated at about 343,000 tonnes of CO2 equivalent. 67% of these emissions are linked to the combustion of fuel necessary to power buses, and 17% from the electricity consumed by rail-based transport modes (metro, RER and trams) as well as that used to operate facilities (RER and metro stations, maintenance sites).
The Bilan Carbone® carbon footprint
In 2006, RATP EPIC, the industrial and commercial public undertaking, was the first public transport operator in France to conduct an overall carbon footprint of its business. In 2015, the group updated its carbon footprint for reference year 2014.
The carbon footprint is evaluated for several reasons:
- To monitor and measure greenhouse gas emissions generated by the company either directly (bus, metro, RER, and tramway traffic; energy consumption of metro and RER stations, etc.) or indirectly (staff commuting to and from work, manufacturing and transport of goods purchased, etc.),
- To identify and rank by priority the leverages for reducing the company’s carbon footprint.
Between 2004 and 2020, RATP has pledged to reduce its greenhouse gas emissions per passenger/km by 20%.
The carbon footprint for the year 2014 based on the Bilan Carbone® methodology confirms the emissions profile described in previous inventories. 75% of RATP’s greenhouse gas emissions can be attributed to energy consumption for traction and buildings (industrial facilities, RER and metro stations, services buildings). The remaining 25% of greenhouse gas emissions not directly related to consumption are derived mainly from purchases (13%) as well as from business travel and staff commutes to and from the workplace (9%).
Altogether, based on directly or indirectly generated greenhouse gas emissions, RATP’s carbon footprint is about 562,000 tonnes of CO2 equivalent.
This carbon footprint does not include emissions pertaining to the construction of RATP’s fixed assets. These emissions are evaluated at 127,000 tonnes of CO2 equivalent. Fixed assets include industrial and services facilities, network infrastructure, trains and buses, computer facilities, etc. This item was not included in the inventory because it is highly uncertain. There is great uncertainty over the necessary input data, including the quantity of materials used and other emissions factors. Plus, changes in construction techniques, notably for infrastructure, make it hard to estimate after the fact the carbon emissions of fixed assets that have already been built.
Reducing the CO2 emissions of bus transport
Bus transport accounts for about 85% of the greenhouse gas emissions linked to energy consumption, which comes to more than 50% of the overall carbon footprint, using the Bilan Carbone® methodology. Two sources of alternative energy are emerging to help evolve bus transport:
- 100% electric buses: RATP was a pioneer in this field with its “Montmartrobus” 100% electric minibus line, which it has operated in the Montmartre district of Paris for the past ten years. Electrical technology is not yet available for longer bus lines. Electric minibuses and midibuses are only operated on Parisian routes.
- Hybrid buses (electric/diesel): in 2011, RATP tested 3 hybrid buses under real operating conditions. Their performances were positive, with a reduction in fuel consumption of about 15%.