Climate Change Task Force

As the world seeks to address the current climate and energy crisis a major sector is not receiving the attention that it should. The three biggest consumers of energy are: the built environment, manufacturing and transport. But while governments focus on the first two of these, transport has taken a back seat.

There are several reasons for this. First, while much attention has been placed on the centralised generation of low-carbon electricity and heat, transport depends heavily on the direct use of petroleum and coal. Moreover, governments are obviously most interested in what takes place within national boundaries, meaning that air and ocean transport have fallen between the international cracks.

This needs to change. In a world of globalised markets, facing a global crisis, the transport sector illustrates how we will need to find intelligent, interconnected and often global solutions.

The complexity of the issues facing the decarbonisation of transport can be nicely demonstrated by the case of London’s airports. This summer I was asked to chair a meeting at the Institute of Civil Engineers to consider the Mayor’s proposal for a new London airport in the Thames estuary. It is an imaginative idea, which could shift the dense tangle of flights paths from their current location above the city to the skies of the unpopulated estuary. If you were designing the London airports from scratch, it would look like an exceptionally good solution. What’s more, a simple extrapolation of current demand forward in time shows that by 2030 even a third runway at Heathrow would not be enough to meet passengers’ needs. A new airport seems like a shoe-in.

However, looking at the problem more holistically throws up some very different considerations. If our priorities were the same today as they have always been, there would be nothing wrong with using simple extrapolations of past behaviour to plan the infrastructure of the future. But the Europe-wide commitment to reducing carbon means that some demand will inevitably need to shift, for example from short-haul flights to high-speed rail networks. There is a high-tech future in getting people around comfortably, quickly and from city centre to city centre, and the potential for investment in high-speed rail has to be fed into the overall equation.

There is also the question of opportunity costs. If the Mayor moves to the next stage and invests £10 million in a full feasibility study, that will immediately put on hold the potential for the Thames estuary to generate energy. Proposals have been mooted for both a wind farm and a barrage, neither of which are likely to be compatible with an airport.

I am not saying that I am either for or against an estuary airport; rather that this case demonstrates how we need to consider all aspects of the transport problem. Making simple extrapolations without taking into account the whole picture can give completely the wrong answer, and could result in massive investment in projects that become expensive stranded assets. If we are to manage our transformation from high to low carbon with minimum risk to our growth, we cannot afford to make such mistakes. We have to be smart.

One argument often made for airport expansion is the additional carbon emissions caused when planes are forced to circle aimlessly overhead through lack of available landing slots. But there are other ways to cut this inefficient stacking. My institution, the Smith School for Enterprise and the Environment in Oxford, has just produced a Roadmap for Transport that was commissioned by Shell. In it, we found that investing in advanced Air Traffic Control systems which create an accurate (time resolved) picture of the traffic in the sky would dramatically reduce the need for stacking even over the busiest airports.

We also found that the aviation industry’s recent announcement that it will reduce emissions per passenger mile by 50% by 2050 is entirely realistic.Competition is driving ever greater efficiency in the design of aircraft and within a few decades planes could have changed beyond recognition, for example to the currently mooted “blended wing” design which combines increased passenger numbers per plane with much greater fuel efficiency—and is also very beautiful.

Given the problems with finding alternative low-carbon fuels for air transport, we also need to give priority to planes when looking at possible uses of second generation biofuels. When we find a way to produce transport fuels effectively from cellulosic food byproducts, we should not waste them on cars or trains for which there are other potential low-carbon options.