Global warming may cause shortages of food and water in some places. It may make the polar icecaps melt, and the sea level rise. One study said that average temperatures could be as much as eleven degrees higher by the end of the century. No one really knows how the world will change if people make it hotter. These are electric cars.
Electric cars have big batteries instead of engines.
Unfortunately, they still make some pollution. The electricity to recharge electric cars comes from powerplants. Powerplants are like factories that make energy for a whole city. A few powerplants make energy from the wind or sun, but most don't. They say that the most harmful activity is the use of cars and light trucks.