Nonrenewable Resources

Humans use a variety of resources whose regeneration rates are too slow to show sufficient increases in stock sizes to be relevant to decision making. Examples include many of the energy sources on which modern economies depend, such as crude oil, natural gas, coal, and uranium, as well as many of the minerals and metals stocks that enter the economy—from iron and copper ores to gravel and sands, to trace minerals important in agriculture and many industrial processes. Other resources could, in principle, be considered renewable—such as tropical forests or fish populations—but current harvest rates are too high to allow for significant regeneration.