The UK Government takes seriously the issue of climate change.   It is therefore rather surprising that it is so supportive of the building of an additional runway at Heathrow, London’s main airport.   In contrast, the Conservative party has announced its opposition to the third runway, preferring instead to build a high-speed rail line from London northwards to Birmingham, Manchester and Leeds.   This could be a key issue in the next general election, particularly for the large number of constituencies in west and central London under the airport’s flight paths.

The high-speed rail proposal prompts questions about the extent to which rail would substitute for flying from regional locations, particularly for travellers in transit via Heathrow.   A further question is the extent to which high-speed rail would encourage travel more generally and hence boost carbon emissions.  

Average travel time has held constant over many decades as people have taken the benefit of investment in the transport system in the form of enhanced access to more distant destinations permitted by higher speeds.  Faster rail travel would therefore be expected to encourage longer distance commuting by train.   It would also be expected to foster longer distance car commuting to stations on high-speed rail routes, since the time saved on the faster train could be used to drive in from more distant villages and towns.   People would spread themselves further across the landscape, giving more choice of homes accessible from city-centre jobs, but at the cost of more carbon emissions and traffic on country roads.   The consequences of new high-speed rail routes for land use need to be brought into the reckoning.