Railways: Carbon Emissions Mr. Sanders To ask the Secretary of State for Transport if he will make an estimate of the likely effects on levels of carbon dioxide emissions of the planned electrification work on the rail network. Paul Clark The Department for Transport is working with the rail industry to assess the case for electrifying the Great Western and Midland Main Lines. Electrifying these two lines would reduce rail's carbon emissions by approximately 3 per cent. or 80,000 tonnes of carbon dioxide per year.