Is it best to remove snow and ice from the car before or after starting the car, from an environmental point of view?

From an environmental point of view, it is best to remove snow and ice from the car before starting the car.

If you start the car before removing snow and ice from it the engine will idle and consume a lot of unnecessary fuel. The exhaust emissions produced during cold starts are also very harmful.

You should never idle the car to warm it up. Use an engine pre-heater instead.