How Is Coal Formed?
Coal comes from plants that have been buried in the earth so long, they turned hard and black. Millions of years ago, much of the earth was swampy and flat. Huge forests of ferns and trees grew in the swamps.
As plants died and fell into the swamp, new plants grew in their places. After a long time, the half-rotted remains of dead plants formed a thick layer of spongy material called “peat.”
After millions of years, the peat became buried deep inside the earth where there was great heat and pressure. The heat and pressure turned the peat into coal. Coal is a non-renewable energy source because it takes millions of years to form.