Walking is not only good for you; it helps the environment as well. However, we all need to use transport every now and then, so when we do, it’s important to make the right choices to save CO₂ emissions.

• Try one of the following ways to get to work: cycling, walking, car-pooling, taking public transport, tele-working. On average, for each liter of fuel burnt in a car engine, more than 2.5kg of CO₂ is released.
• Try to avoid short car journeys because fuel consumption and CO₂ emissions are disproportionately higher when the engine is still cold. Research shows that one in two urban car journeys is for less than three kilometres – a distance that can be easily cycled or walked.
• Try washing your car by hand or using a pressurized water jet instead of going to a car wash. Car washes use more electricity and water than the old fashioned way.
• If you replace your car, consider the fuel economy of your new vehicle. Under European legislation, car manufacturers must display information about CO₂ emissions and fuel consumption of new cars in showrooms and advertisements.
• Don’t let your car warm up while stationary – the amount of fuel that warming up consumes is greater than what you save by starting your journey with a cold engine.
• Make sure you have correct tyre pressure: if the pressure is down by 0.5 bars, your car uses 2.5% more fuel to overcome the resistance and thus releases 2.5% more CO₂.
• Consider using low-viscosity motor oil. This lubricates the moving parts of the engine better than ordinary oils, reducing friction. The best oils can reduce fuel consumption and CO₂ emissions by more than 2.5%.
• Don’t leave an empty roof rack on your car. This can increase fuel consumption and CO₂ emissions by up to 10% due to wind resistance and the extra weight – removing it is a better idea.
• Don’t speed – you will use less petrol and emit less CO₂. Driving faster than 120km per hour increases fuel consumption by 30% compared to driving at 80km per hour. 4th, 5th and 6th gears are the most economical in terms of fuel consumption.
• Have you heard of eco-driving? It can lower fuel consumption by 5%. Set your car in motion without pressing down the throttle, shift to a higher gear as soon as possible and keep a steady speed.
• Use air conditioning sparingly, it increases fuel consumption and CO₂ emissions by around 5%. When it’s hot, drive for a few minutes with open windows, then close them and turn on the A/C. This will save you the fuel needed to bring down the initial temperature.
• Try to travel by train! One person travelling by car alone produces three times more CO₂ emissions per kilometre than if this person were travelling by train.
• Explore alternatives to flying. Flying is the world’s fastest growing source of CO₂ emissions. If you fly, then consider ‘offsetting’ your carbon emissions. There are organisations that will calculate the emissions you have caused and invest money in renewable energy.
• Bicycles produce neither greenhouse gases nor pollution and are therefore the least polluting mode of transport.
• Going on a trip?
  If getting there by car, instead of by train or bus, be generous and share the space. By taking other people who might have made their journey in a separate car, you’re putting one less car on the road.
• When travelling, choose eco tourism.
  Developing countries often gain little financial benefit from the influx of visitors to their shores. Only around 30 % of the money spent by tourists on their holiday remains in the host country. Eco tourism is promoted in some countries. For sustainable destinations, explore EU’s catalogue at www.eco-label.com
• Going on a longer trip? Choose wisely.
  An average new car generates 160 g/km of CO2 equivalent per passenger, a plane 100 – 250 g/km, a bus 40 – 80 g/km, and a train 40 – 160g/km. If going by car, take as many passengers onboard as possible as it will reduce the CO2 emissions per person.
• Travel responsibly!
  Fly only for distances greater than 700 km. Otherwise take the train. A transatlantic flight produces almost half as much CO2 as an average person produces over a period of one year while meeting all his or her other needs, such as lighting, heating and car travel!

From: http://ec.europa.eu/environment/climat/campaign/control/walk_en.htm