Abstract for presentation at 14th IUAPPA World Congress

All human activities generate, directly or indirectly, greenhouse gas (GHG) because it rely directly or indirectly on fossil fuel use. In france, as in many industrial countries, transports represent about 30% of energy consumption and are responsible for a great part of GHG emissions.
Until now, emissions factor of goods and private passenger transports are well known, but it is not the case for public transports modes.
In a first time, this study consists on the assessment of Parisian public transport company GHG emissions using the Bilan Carbone® method developed by the French environment agency (ADEME). Emissions caused by all the process necessary for the existence of public transports are calculated: space heating, energy consumption, freight shipments, waste treatment, professional travel... For each source of CO₂ or other GHG, energy consumption, kilometres travelled, quantities of materials purchased are converted into amount of carbon emitted.
Results are then used with the aim to calculate new emission factors of different public transport modes (in gram of CO₂ per passenger.kilometre).
New calculated emission factors will allow making comparison between many situations: type of energies (diesel, bio-diesel, electricity…), of vehicles, use of dedicated lanes, comparison between train, tramway and bus modes and travelling during rush hours... Then we will make propositions with the intention to reduce transport GHG emissions in big cities like Paris urban area.