Emissions targets for London stand little chance of being achieved unless the Greater London Authority (GLA) takes radical steps, one of which could be the removal of all cars from both inner and outer London, according to a report today at London School of Hygiene & Tropical Medicine (LSHTM) to launch the Lancet Series on Energy and Health.

Climate scientists argue that rapid reductions will be needed if England to avoid dangerous climate change[2], even going beyond the GLA commitment to reducing London’s carbon dioxide emissions by 60% by 2025[1]. A team of experts from LSHTM and the Transport Studies Unit (Oxford University Centre for the Environment) will today reveal that London is on course to reduce land transport emissions by only 10%-23%[3,4].



They do, however, offer a radical vision which could achieve a 72% drop in emissions by 2030 – a figure that is 83% lower than the current UK average. The solution involves combining a car-free London with high levels of active transport (for example walking and cycling) and realistic but challenging energy-efficient improvements.

Land transport emissions in London have remained stable since 1990 and are now responsible for about 14% of total emissions. Although cycling is gaining popularity, with an 83% increase in the capital since 2000, more than seven out of ten (72%) car journeys in London cover a distance shorter than 8 kilometres.

There is evidence of substantial negative health effects from motorised transport in London[5]. Replacing car trips with active transport such as walking or cycling would lower emissions and offer greater health gains than other options. In 2003, only 32% of men and 26% of women in London achieved minimum activity recommendations[5].

Calculations show that a car-free inner London scenario equates to a 49% reduction in emissions[7]. Because most London car trips are within outer London, changes in inner London boroughs alone were not found to be sufficient to meet the GLA emissions target. The car-free inner and outer London model was found to bring about a 72% reduction in emissions, with active transport making up 53% of all trips. Given the lower starting point, this means 83% lower emissions than the UK average for 2000.

The authors highlight the many benefits, in terms of public health and safety, that the adoption of the car-free scenario would achieve. Not only would the former car users benefit in terms of improved health as a result of greater physical activity, but as active transport in the form of walking or cycling increased, more people would be willing and able to comfortably walk or cycle longer distances.

They also point to the strong link between pedestrian injury and deprivation, with rates in the most deprived London areas over twice those in the least deprived. In London, as in virtually all locations, walking is the main transport mode of the poor. With fewer cars, people would be exposed to less traffic danger. Although pedestrians and cyclists are exposed to greater risk than car drivers, previous studies have shown that as the number of pedestrians and cyclists increase, so the danger per km walked or cycled falls.

James Woodcock, who led a team of researchers at the London School of Hygiene & Tropical medicine, comments: ‘Only the car-free greater London scenario is close to achieving the emission reductions required by 2030. Even then we need to reduce carbon fuel use on our public transport. Car-free streets could transform the quality of our urban environment, while improving health. Although London has made small improvements, achieving a car-free city would require a dramatic move in favour of walking and cycling’.

A separate paper uses London travel data to identify four archetypal car using groups in London: Claire, a 10 year old girl; Lucy, a 40 year old mother; Tom, a 50 year old man living and working in outer London; and Derek, a 78 year old man. It calculates the increases in physical activity and energy expenditure that would result if they transferred their car journeys to walking, cycling and public transport, with occasional trips by taxi. By doing so, they would expend an average of 139,300 kJ of energy a year, equivalent to an average of 4.5 kg of fat. Lucy would reduce her risk of breast cancer by 25% and increase her life expectancy by between 1 and 2 years, while Tom would enjoy a 20-40% reduction in the risk of premature mortality and around a 30% reduction in risk of type 2 diabetes.

Notes
[1] Anon. Action today to protect tomorrow: the mayor’s climate change action plan. London: Greater London Authority, 2007.

[2] Meinhausen M. What does a 2oC target mean for greenhouse gas concentrations? A brief analysis based on multi-gas pathways and several climate change sensitivity uncertainty estimates. In: Schellnbuber HJ, Cramer W, Nakicenovic N, Wigley T, Yohe G, eds. Avoiding dangerous climate change. Cambridge: Cambridge University Press.

[3] Watkiss P, Brand C, Hurley F, Mindell J, Pilkington A. Informing transport health impact assessment in London . London: NHS Executive, 2000.

[4] Action today to protect tomorrow.

[5] The BAU scenario resulted in a 10% lower emissions per head compared to 2000, a reduction which was largely due to the increases in use of public transport and cycling in London since 2000 (although, the authors note, this optimistic scenario would be less in evidence in other UK cities, where rates of cycling and public transport use are not as high).

[6] Anon. Health Survey for England 2003. Vol 2, chapter 5: Physical activity. pp 108–42.

[7] Using the 2001 London Area Transport Survey (LATS) of trips by Londoners, the authors estimated the effect of three transport scenarios on emissions in 2030. Scenario 1 represented business as usual (BAU). Scenario 2 envisaged a car-free inner London, with greater energy-efficiency and stable trip length. Based on data from 2000, it quantified the effect of transferring 90% of car journeys of less than 8km in inner London to active transport (cycling or walking) with the remainder transferred to taxis, and all car journeys over 8km transferred to public transport. Scenario 3 envisaged the transfer of journeys as in scenario 2 but for both inner and outer London, combined with greater reductions in fossil fuel use by public transport and improved local accessibility.

- London School of Hygiene & Tropical Medicine (LSHTM)