Coal is a nonrenewable resource because ______.

Coal is a nonrenewable resource because it takes millions of years to form. The process begins with the decay of plant material in swampy, low-oxygen environments, which creates peat. Over time, geological processes bury the peat and it becomes subjected to high temperatures and pressures. This transforms the peat into coal. Since this process takes so long, we cannot rely on it to replenish the coal supplies that we use for energy production in a human timescale. Therefore, once we use up the existing coal deposits, there will be no more available for future use, making it a nonrenewable resource.