One alternative to burning non-renewable fuels, which harm the environment, could be to burn

Global warming, acid rain and general air pollution from car exhaust occurs from burning fossil fuels. The global warming occurs because of a "green house effect" where sunlight is trapped inside our atmosphere due to air pollution. Acid rain occurs when the products of combustion, sulfur dioxide, nitrous dioxide and nitrogen dioxide mix with rain water.

Each of these impacts is very extensive. Each fossil fuel has individual impacts related to their use