It saves money and prevents pollution. Keep the car, but try taking the bus to work. Often you can get there faster, and it helps the environment. It will produce fewer gases, and less of the pollution linked to global warming. Poorly maintained cars account for half of the smog producing emissions.
Cars have quite an effect on the environment.
Minimise that effect by having regular oil changes and exhaust system inspections. Look for a fuel-efficient car when making a purchase. Check the brakes during your next tuneup. If they are dragging on the wheels, fuel efficiency is lowered. Lower fuel efficiency produces more emissions linked to global warming.