Cars are powered by what you can an internal combustion engine. This means that the petrol is ignited by the spark plug in your car and the chemical energy released from the burning of petrol is used to move the various parts of the car to make it drive.
The trouble with burning fuel is that we create other emissions such as carbon dioxide, carbon monoxide and nitrogen. Our planet struggles to cope with turning it all back into oxygen. This is part of what’s causing climate change. It’s up to engineers to help find new ways to power cars that don’t emit as much or not emit anything at all.
William Scott-Jackson answered on 26 Jun 2015: