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Transport and Travel

Transport and Travel

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Reducing our transport impact

The need to take action on climate change is more pressing than ever. Transport is one of the main causes of the problem: making up a quarter of the UK’s greenhouse gas emissions. There are easy ways to reduce emissions and have a positive impact on our health and on the wider environment.

Although the UK’s carbon emissions have dropped slightly since 1990, gains in some areas have been undermined by transport growth. Emissions from cars, lorries and aeroplanes continue to rise, and the problem is not limited to climate change. Traffic pollution leads to tens of thousands of early deaths and thousands more are killed in road accidents.

This information draws on the findings of CAT’s Zero Carbon Britain (ZCB) project, and gives advice on the transport choices that can move us to a zero carbon future.

Car use

About 40% of the UK’s transport emissions come from private cars. An astonishing 6 out of every 10 cars on our roads contain just one person; for commuting or business journeys, about 85% carry only the driver.

To reduce your impact, you can switch to two wheels or two legs, share lifts with colleagues & friends, set up a local car club, or make more use of buses and trains.

Children cycling to CAT
Cycling to CAT

Cycling and Walking

About one-fifth of all car emissions come from journeys of less than 5 miles. Cycling and walking more (and encouraging others to do so) will help to reduce these journeys. This is a good first step to reducing carbon emissions, and you’ll also feel much healthier!

If your regular journey is too far to cycle, you could consider using an electric bike. This would allow you to cover much longer distances and is more efficient and cheaper than an electric car.

Cycling and walking also combine well with public transport. In the UK, half of us can walk to a train station in under 30 minutes, or cycle there in under 10 minutes.

Public transport

Switching to public transport or sharing journeys will reduce carbon emissions by a half or more. They are a much more efficient way to use both fuel and rpad space. Per passenger, a coach takes up less than thirteen times the space of cars on motorways. If local buses or trains are unsatisfactory, lobby your local council and MP to improve things – you can find contact details via

Trams & light rail improve city travel. After the Tyne & Wear Metro opened, congestion in Newcastle reduced, and traffic could move more freely. One-fifth of all Manchester Metrolink journeys would previously have been by car, and in some areas of the city car levels have dropped by half.

Car sharing

Car clubs offer an alternative to owning a car, and reduce car use while providing the convenience of private transport. They offer both carbon and financial savings, as people only make use of the vehicle when they really need to. Research shows that one car club car replaces four or five privately owned vehicles, and travel patterns change considerably. In Berlin, car club members reduced the miles they drove by 53%, walked or cycled 28% more and used public transport 35% more than private car owners.

In the workplace

A workplace travel plan can reduce car use by encouraging cycling, car share schemes and the use of public transport. A plan is likely to include some sort of parking charge to discourage car use, but needs incentives as well. Incentives for more sustainable commuting could include a car-share system, subsidised bus tickets, or even dedicated shuttle buses. It’s also important to have good provision to encourage cycling, such as secure bike storage and showering facilities.

A travel plan also saves money, by reducing the expense of maintaining parking spaces. When Orange moved 400 staff from the Bristol outskirts to the city centre, far less parking was available. The limited parking was allocated with permits. Priority was given to those with child care responsibilities, those who shared cars, and those for whom public transport, cycling or walking would be difficult. Others got a monthly payment similar to the price of a public transport season ticket. Showers, lockers, pool bikes and secure storage were provided to encourage cycling, and an intranet car-share database was set up.

charging an electric vehicle

Electric Vehicles

In our Zero Carbon Britain report we see electricity as the key transport fuel of the future. Electric vehicles are already less polluting, and this will improve as the UK electricity grid takes on more renewable energy. Developments in battery technology will also improve performance and reduce costs. Several manufacturers are now launching new electric cars and bikes.

Hydrogen fuel

Hydrogen is an extremely common element and when used as a fuel gives zero carbon emissions. However, the process  of extracting it from compounds such as water or natural gas uses lots of energy. It’s currently better to use electricity to directly power electric vehicles, and limit the use of hydrogen to cases where battery use is difficult, such as buses & goods vehicles.

Biodiesel & Bioethanol fuel

Bioethanol made from sugar or starch can replace petrol, while biodiesel made from vegetable oil can replace diesel. Most transport fuel sold in the UK already contains 5% biofuel, to meet the Government’s Renewable Transport Fuels Obligation (RTFO). Going beyond this proportion is difficult for both technical and environmental reasons. Technical issues include the alterations needed to existing vehicles and our fuel supply infrastructure.

There are environmental concerns because the carbon emissions from biofuels can still be very high. Emissions are due to land use changes, such as deforestation, and to fertiliser use and processing. When all these factors are included, it’s unclear if biofuels have lower greenhouse gas emissions than the fuels they replace. There are also concerns about impacts on biodiversity and water availability, and competition for land needed to grow food.

Making ‘second generation’ biofuels from wood or grasses causes fewer problems but there will still be limited land available. We can produce a small quantity of biofuel sustainably, and this is best used where electricity would be unsuitable. At present this could include shipping, some heavy goods vehicles, farm machinery, and aviation.


UK Greenhouse gas emissions attributable to air travel doubled between 1990 and 2005, and have since levelled out. Aviation accounts for 22% of carbon emissions from UK transport, and it’s currently difficult to decarbonise air travel. There’s only limited scope for efficiency savings and using biofuels in aircraft. A big reduction in air travel is therefore inevitable if we are to reduce our carbon emissions. For our Zero Carbon Britain scenario we calculated that we need to cut air travel to one-third of the current level.

Cutting down the number of flights you take will cut tonnes from your carbon emissions. A short-haul air flight gives off 4½ times as much carbon dioxide as the same journey by train. The channel tunnel leads to high-speed rail links all over Europe, so why not take advantage?

Related Questions

How are biodiesel and bioethanol used as fuel?

Biodiesel is a generic name for a variety of similar fuels that can be used in place of fossil diesel. In general, you would need to either alter vegetable oil to make it chemically similar to diesel, or alter your engine so that straight vegetable oil (SVO) can be used as fuel. Waste cooking oil can be used if it is carefully filtered to prevent damage to the engine from dissolved fats and food particles.

However, if you are thinking of undertaking the conversion of oil or of your car then bear in mind that only very limited quantities of used cooking oil are available, and the production of biodiesel from new vegetable oils can have a very high environmental impact. There may also be little cost saving overall

Bioethanol made from sugar or starch can replace petrol, but only a mix of about 5% bioethanol with petrol can be used in an existing car without any problems. A high proportion of bioethanol in petrol may damage rubber seals and aluminium parts in the engine. Some ‘flex-fuel’ vehicles were designed with hardened components, non-rubber seals and larger fuel lines to cope with the abrasiveness of the fuel. Wider use of bioethanol would also require modification of the fuel supply infrastructure: pumps, tankers and storage facilities.

Should I buy carbon offsets?

Because a plane flight is a single big carbon impact, many companies promote methods of neutralising the impact of those emissions, such as investing in renewable energy or planting trees.

One flight is responsible for roughly 0.17 kilograms (kg) of carbon dioxide (CO2) per passenger-kilometre. These emissions should be multiplied by a factor of 2.5 due to the increased warming effect of upper atmosphere emissions. However, some calculators don’t include this factor when evaluating offsets. A return flight from London to Malaga (2,300 km) would emit almost 1 tonne of CO2 equivalent.

However, we are very wary of offsetting in principle because what we really need to be doing is reducing our own emissions as much as possible. There is the danger that carbon offsetting schemes leave people feeling that it is fine to fly as they can just buy their way out of the consequences. It is far better to reduce your emissions at source by travelling by train rather than plane and taking holidays closer to home.

If you have to fly, you could invest in carbon saving measures closer to home instead of offsetting. You could insulate your home to a very high standard (if you are a homeowner). Or invest in an electric car or bike to reduce the impacts of car travel, or in a community renewable energy scheme. Or you could just donate directly to charities & non-profit organisations working in this area, rather than via an offsetting company.

If your own options are limited and you do want to investigate offsetting, then Ethical Consumer have more advice on avoiding bad offsetting schemes. As they mention, schemes that plant trees are not as common now, as there were many problems with how these were managed. We do need to address deforestation, but poorly sited tree plantations can have negative effects on habitats, water supplies and local people. Young trees use lots of water, so if many are planted they can reduce the water available to farmers downstream. When a tree rots or is burned, any carbon absorbed is released again. The trees need to be allowed to grow for many years, and the forest then needs to stay in place for centuries to come.

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