Natural resources are materials found in nature that humans use, such as minerals, energy, and water.  Most energy sources are non-renewable, meaning they are used up faster than natural processes can replace them on a human timescale.  Many nonrenewable energy sources are fossil fuels. Fossil fuels formed millions of years ago from the buried remains of plants and animals that were changed by heat and pressure over time. The three main fossil fuels are coal, oil, and natural gas.Coal is the most abundant fossil fuel and forms from plant remains, containing at least 50 percent plant material. In contrast, oil, also called petroleum, is a thick, black liquid hydrocarbon that forms from the buried remains of microscopic marine organisms. Natural gas is another fossil fuel, but unlike oil, it is a gaseous hydrocarbon that often forms above oil deposits because gas is lighter than liquid oil.  These fossil fuels are extracted from the ground through mining and pumping. However, the amount that can be recovered—known as reserves—is decreasing as these energy resources are used.

Another nonrenewable energy source is nuclear energy. Nuclear energy is produced when uranium atoms undergo fission or splitting. When the atoms split, they release thermal energy. This heat is used to warm water and produce steam. The steam spins a turbine connected to a generator, which produces electricity. Nuclear power plants can generate large amounts of energy and do not release air pollution during operation. However, nuclear energy produces radioactive waste that must be safely stored and contained for thousands of years.

In addition to energy resources, people also depend on mineral resources. Mineral resources are deposits of useful minerals found in Earth’s crust. These deposits are called ores, which contain enough of a mineral to be extracted for a profit. Some mineral resources are nonmetallic, meaning they are not used as fuels or sources of metals.

Industrial minerals include sandstone, which is used to make glass; halite, which is used for table and road salt; and garnet, which is commonly used in sandpaper. Other minerals are used as building materials, such as aggregate in concrete, gypsum in plaster and wallboard, and stone like granite, limestone, and sandstone.

Review:

1. What is a non-renewable resource?
2. What is the most abundant fossil fuel?
3. What is a mineral resource?