The LGV Rhin-Rhône high-speed line is where it's all happening The 140km stretch between Dijon and Mulhouse is the only high-speed rail line currently under construction. The project kicked off in 2006 and is due to enter service in December 2011, with 12 million passengers expected every year. Project partners RFF and the SNCF have worked together with ADEME (the French environment and energy management agency) to calculate the greenhouse gas emissions over every phase of the work.

It's called a carbon footprint, but the key thing here is that greenhouse gas emissions are calculated for the whole life of the project - the design and construction of the 140 km stretch of line, the two new stations, the maintenance centres, the 30 new TGV trains and also the workshops where the trains will be serviced. 30 years of train services on the line have also been taken into account, with all the power consumption and waste that they entail. All the greenhouse gas emissions were systematically worked out by ADEME's scientists.

All in all, 1.9 million tonnes CO2 equivalent will be released over 30 years of the Rhin-Rhône project. Think that's a lot? It is the equivalent of one year's emissions from a city of 200,000 inhabitants (like Dijon, for instance). What are the main sources of pollution? 42% of greenhouse gas emissions come from the initial construction and 53% come from the power sources used to drive the trains.

If you now subtract the emissions that will be prevented by 1.2 million travellers every year taking the train rather than their car or the plane, the carbon footprint will have balanced itself out by the 12th year of the line's operation. The break-even point is in 2024, after which the project will be 'carbon positive', having offset the initial 'carbon investment'. Thousands of passengers every day will enjoy ecomobility, in the knowledge that they are helping the environment.

Environmental action. This new high-speed line will contribute to France's goal of reducing its greenhouse gas emissions by 22% between now and 2020. Transport is a significant factor in emissions (27%) and road transport generates 90% of the transport-related pollution. It is important to change our modes of transport, and the plans to build another 2,000km of high-speed lines is yet another example of forward thinking.