How Can I Stop Climate Change: What is it and how to help. Литагент HarperCollins USD

reducing carbon dioxide emissions.

      The city of Curitiba in Brazil has been held up as a model of what public transport can achieve if investment and urban planning keep the needs of people in mind. The city, which has a growing population of more than 1.6 million people, invested in buses as its main public transport, creating special bus-only avenues. The system, which is cheap to use, carries some 2.14 million passengers a day despite high levels of car ownership. The result has been cleaner city air and some of lowest rates of fuel consumption per person in Brazil.

      Freiburg in Germany (see also pp.94-95) is one of many European cities to have developed a low-carbon approach to getting about. The city has 160 km of sign-posted cycle paths, cycle-only streets and special access on one-way routes. Buses and trams carry 67 million people a year, with cheap tickets for families.

      In France the Mayor of Paris has introduced a low-cost bike rental scheme in the capital, providing bicycles at 750 stations around the city. Users of the Velib bike scheme can buy either an annual pass (priced at £20) or a one-day pass (less than £1), with short journeys completely free. Paris has some 230 miles of cycle paths and the number of cyclists in the city has increased by 50 per cent in the past ten years.

      A charge on drivers entering the city centre, combined with investment in public transport, has cut the level of traffic in inner London, with increases in the numbers of people travelling by tube and bus. One opinion survey found that 1 in 5 drivers would leave their car at home and use public transport if road charging schemes were introduced across the UK.

      Improvements to public transport can tempt drivers out of their cars for longer distance trips, with both coach and rail travel offering lower carbon dioxide emissions per passenger mile. Planning policies can also have an impact – for instance local development plans can ensure new shops are accessible by public transport or by foot.

      A UK government study found that with the right policies, emissions from road transport could be reduced by 60 per cent from 1990 levels by 2030. Some of these savings depend on using hybrid vehicles and alternative fuels, but measures such as road pricing, energy-efficient driving and changes to freight distribution systems also had a role to play.

      VIVE LA REVOLUTION:

      ‘This is about revolutionising urban culture,’ says Pierre Aidenbaum, mayor of Paris’ third arrondissement, as the capital provides more than 10,000 bicycles for Parisians and visitors alike.

      potential emissions savings from different transport measures

measure	saving*
Low emissions vehicles	18.3 – 9.1
Alternative fuels	9.1 – 1.8
Greener driving	4.6 – 2.5
Improved freight/local production	2.5 – 0.7
Travel plans, car clubs, car sharing	2.4 – 0.9
Better planning	2.4 – 0.5
Road pricing	2.3 – 1.1
Use of IT	1.2 – 0.3
Rail for air	0.7 – 0.5

      *million tonnes carbon per year

      Further savings would be possible if we changed the way we live in our cities and towns: better inner city housing and pedestrian and cycle access to shops and services encourage people to use their cars less. When planners redeveloped the German capital of Berlin, they included a car-free zone in the centre as part of the city’s commitment to cut emissions by 40 per cent by 2020. Homes in the car-free area are surrounded by pedestrian and cycle paths, but no parking spaces. Local shops and services mean residents do not need to use a car. A new building code now restricts parking for new buildings in the city.

      Better public transport, towns designed for pedestrians, less congestion, less pollution, and fewer journeys by car could all improve our quality of life.

      air travel

      Air travel accounts for a growing percentage of the UK’s carbon dioxide emissions. If current levels of growth continue, emissions from aviation could account for 80 per cent of the UK’s entire carbon budget by 2050.

      There is certainly scope to make aeroplanes more efficient. Improvements have been made since the first jets came into service in the 1960s – although early jets were much more polluting than their propellor-driven predecessors and jets have only recently reached the same level of efficiency as the engines of the 1950. Aircraft manufacturer Boeing advertises that its recent 747-8 Intercontinental aircraft has improved fuel efficiency by 15 per cent, resulting in 75 g per passenger km (that’s equivalent to 202 g/km if we count the effect of emissions in the upper atmosphere). New designs could help improve aircraft efficiency. The flying wing – or blended wing-body design, which extends the passenger cabin into the wings of the aircraft, could make planes lighter and more aerodynamic, so saving fuel. Its champions claim it could reduce emissions by 90 per cent within 50 years. Plans are still on the drawing board, however, and while engineers are confident that the planes could be built, they are not yet considered commercially viable.

      Research by the Tyndall Centre for Climate Change Research suggests that for aviation to play its part in keeping carbon emissions within safe limits, it would need to make efficiency gains much faster than it has ever done in the past. In fact the Tyndall Centre’s research suggests aircraft engine efficiency will improve by such a small amount each year that any gains would be more than cancelled out by the rapid growth in the number of flights we take. One problem with any efficiency improvements in aviation is that they can take such a long time to come into effect. The life span of the average passenger aircraft is some 30 to 50 years and two-thirds of all the aircraft likely to be flying in 2030 are already in use. Carbon cuts are needed long before that.

       Aviation’s growing share of the UK’s projected carbon emissions

      Future growth of air travel means its share of carbon emissions will become more and more damaging.

       Government projections for aviation’s emissions may be too conservative – others suggest aviation’s emissions in 2050 will make up far more of the UK’s total. Source: Draft Climate Change Bill (2007)

      More immediate savings can be made by changing the way air traffic is managed – effectively reducing the time that an aircraft spends in the air. One assessment suggests this could reduce emissions by between 6 and 12 per cent.

      The European Union intends to bring aviation within the Emissions Trading Scheme to provide an incentive for the aviation industry to reduce emissions. While some airlines have welcomed the proposal, modelling suggests it is unlikely to result in lower emissions as it is unlikely to have a major impact on ticket prices and passenger numbers.

      Indeed, it is hard to see how savings from efficiency can compensate for the rapid growth in emissions from flights. Experts at the IPCC concluded that while savings are possible, these will only partly offset the growth in aviation emissions globally. Offsetting schemes may make us feel better as passengers, but the potential to offset all our emissions simply does not exist.

      One way forward would be for airlines to pay for the environmental damage they cause. Air passenger tax could be raised to cover the environmental costs and curb growth in demand. The need to restrain growth also places a huge questionmark over airport expansion plans in the UK. The only really effective way to cut emissions from the aviation sector is to manage the amount of flying that goes on – that doesn’t mean we have to fly less than we do now, but it does imply not flying much more. It also means doing something about airfreight, for example through lowering consumption of imported goods.