Travel to School
If you usually get driven to school, you could find out if there is another way to get there.
You could use public transport or take a school bus. Because they can carry lots of people, taking a bus or a train reduces the amount of CO2 released into the air.
If you live close to your school, why not walk or cycle? As well as being better for the environment, it's a great way of getting some exercise.
If using a car is the only way you can get to and from school, find out if you and your friends could set up a car sharing scheme. Instead of travelling in separate cars, you could all get to school in the same one instead.