Nonrenewable resource: A natural resource that cannot be produced, regrown, or reused fast enough to keep up with how quickly it is used. Fossil fuels such as coal, oil, and natural gas, for example, take millions of years to develop naturally. Thus, their supply for people to use is considered nonrenewable.
Nitrous oxide
Nitrous oxide: A colorless, odorless greenhouse gas. It occurs both naturally and as a result of people’s activities. Major sources include farming practices (such as using fertilizers) that add extra nitrogen to the soil, burning fossil fuels, and certain industrial processes.
Natural gas
Natural gas: A fossil fuel that is an odorless, colorless gas. Natural gas consists of 50 to 90 percent methane.
Methane
Methane: A colorless, odorless greenhouse gas. It occurs both naturally and as a result of people’s activities. Methane is produced by the decay of plants, animals, and waste, as well as other processes. It is also the main ingredient in natural gas.
Magma
Magma: Hot, melted rock under the Earth’s crust. Magma becomes lava when it is released through a volcano or other methods.
Light-emitting diode (LED)
Light-emitting diode (LED): A device that uses a material called a semi-conductor to produce light without using a lot of electricity. LEDs are commonly used as indicator lights on electrical devices, but they are now being used more often for general lighting.
Latitude
Latitude: A measure of how far north or south a particular place is located on the Earth. Latitude is measured in degrees (°). The equator has a latitude of 0°. The North Pole’s latitude is 90° north, and the South Pole’s latitude is 90° south.
Kilowatt-hour
Kilowatt-hour: A unit for measuring the use of electricity. The cost of an electric bill depends on how many kilowatt-hours the customer used. A microwave or toaster running for an hour will use about 1 kilowatt-hour.
Invasive species
Invasive species: A type of plant, animal, or other organism that does not naturally live in a certain area but has been introduced there, often by people. An invasive species can spread quickly, especially if it has no natural predators in its new home. An invasive species can hurt native species, disrupt ecosystems, and create problems for people (for example, weeds and insects that damage crops).
Infrastructure
Infrastructure: Physical structures that allow society to function. Examples include buildings, roads, water pipelines, sewers, electric power lines, railways, and airports.
Infrared radiation
Infrared radiation: A type of electromagnetic radiation. The Earth gives off energy in the form of infrared radiation, which is not visible to the naked eye and feels like heat to the human body.
Infectious disease
Infectious disease: A disease caused by bacteria, a virus, or other organisms.
Incandescent light bulb
Incandescent light bulb: The most common type of light bulb, which produces light when electricity heats a thin metal wire. Incandescent bulbs use more electricity than newer compact fluorescent light bulbs (CFLs).
Hypothermia
Hypothermia: A medical condition in which a person’s body temperature becomes abnormally low, usually because of exposure to cold air or water. Severe hypothermia can lead to death.
Hydroelectric dam
Hydroelectric dam: A power plant that uses the energy from moving water to produce electricity. Moving water spins a turbine, which is connected to a generator.
Heat wave
Heat wave: A long period of abnormally hot weather, typically lasting for several days.
Heat stroke
Heat stroke: A medical condition that results from being exposed to high temperatures. A person’s body temperature rises rapidly and he or she is unable to cool down by sweating.
Habitat
Habitat: The place or environment where a plant or animal naturally lives and grows.
Ground water
Ground water: Water that occurs below the surface of the Earth, where it occupies spaces in soil or layers of rock. When rain falls to the ground, some of it sinks into the ground and becomes ground water.
Greenhouse gas
Greenhouse gas: Also sometimes known as “heat trapping gases,” greenhouse gases are natural or manmade gases that trap heat in the atmosphere and contribute to the greenhouse effect. Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and fluorinated gases.