The Department for Transport does not hold data in the form requested. The rail industry reports its traction related carbon emissions annually to the Office of Rail Regulation.
In 2007-08, the most recent year for which figures are available, the rail industry reported combined freight and passenger traction carbon emissions of 3.4 million tonnes of carbon dioxide. Of this 2.7 million tonnes relates to passenger operations. This information is found in Rolling National Rail Trends 2008-09 on the Office of Rail Regulation website at:
http://www.rail-reg.gov.uk/server/show/nav.2026