Transport coughs out about a quarter of the UK's greenhouse gas emissions.
It's also a major source of air pollution – linked to 36,000 early deaths a year in the UK.
There are lots of ways to reduce your impact on the planet.
Put the brakes on climate chaos with these top tips.
1. Fly less long-haul
Concerned about your carbon footprint? Holiday closer to home with these no-fly holiday ideas.
Taking one long-haul flight is as bad for the climate as a whole year's worth of driving.
Green aviation isn't a thing. Offsetting schemes aren't working – an EU report showed that 98% support carbon cuts that would have happened anyway. And renewably-powered, electric planes are a distant dream.
2. Take the train
Train journeys are much better for the climate than short-haul flights. Book well in advance for the cheapest fares.
If you really need to fly, try to limit yourself to one flight a year.
3. Walk or cycle
Cars spew out a lot of greenhouse gases. A fifth of that planet-warming pollution happens during journeys less than 5 miles – short journeys that could be made by foot or bike.
Walking and cycling are much healthier than sitting in a car. Even in areas of high air pollution, the benefits of exercise outweigh the risks linked to dirty air.
4. Choose public transport
You'll clock up fewer climate-changing emissions using public transport than driving around in a private car.
You'll also be helping to clean up the UK's dirty air – much of which comes from car exhausts.
We're campaigning for the government to fund improvements to public transport – encouraging people to leave the car at home.
5. Switch to an electric car
If you can't manage without a car, UK electric cars emit 50% less carbon pollution than diesel engines, according to a lifecycle study.
And – because they're much cheaper to run – the lifetime cost of a new electric car is no more than a normal car. Newer models can go over 250 miles on one charge, and faster charging stations are popping up.
Find out more about electric cars from our partner Ethical Consumer magazine.
6. Hire a car or join a car club
Making and running a car uses a lot of energy – about the same as running 3 hot baths every day.
Owning a car can also be expensive. Kwik-Fit estimates average costs of around £380 a month when you add the running costs, if you buy new rather than second-hand"
Sharing or hiring a car when you need one is likely to be the cheapest option. Find out more about car sharing and car clubs.
7. Green your driving habits
Save fuel and save cash with greener driving habits. For example, regularly check your tyre pressure, remove the roof rack and keep windows closed to reduce drag.
Driving at 50 mph uses 25% less fuel than 70 mph. Accelerating and braking gently also helps.
Switching off the engine rather than idling will cut fuel consumption and help reduce air pollution. Get more fuel-saving tips from the Environmental Transport Association.