Environmental Science Terms

Renewable Energy

Energy that comes from sources that are always available in the natural world and cannot be used up.
Direct Solar Energy

Used to heat water, buildings, and generate electricity.

Indirect Solar Energy

Wind, biomass, and hydropower.


Energy that isn’t directly powered by the sun, instead it is used to power another process that provides energy.

Passive Solar Energy
Technique that makes the best use of regular building materials to trap heat with no mechanical devices to distribute the collected heat.
Active Solar Energy
Requires a collected to collect and absorb solar radiation. Pumps or fans are used to distribute the heated air or heated absorbing liquid.
Fuel Cell

A device that directly converts chemical energy into electricity without needing to produce steam and use a turbine and generator.


Requires hydrogen from a tank and oxygen from the air.

Geothermal energy
The use of energy from Earth’s interior for either space heating or generation of electricity.
Wind energy
Electric or mechanical energy obtained from surface air currents caused by solar warming of air.
Tidal Energy
A form of renewable anergy that relies of the ebb and flow of the tides to generate electricity.
Hydropower Energy
A form of renewable energy that relies on flowing or falling water to generate mechanical energy or electricity.
Biomass: Ethanol, Methanol, and Biodiesel

Plant material, including undigested fiber in animal waste, used as fuel.


Converted into liquid fuel. Biodiesel is made from plant or animal oils and is becoming popular as an alternative for diesel in trucks and farm equipment.

Flex-fuel vehicle

Energy conservation

Using less energy, as for example, by reducing energy use and waste.


Carpooling — uses less fuel

Energy Efficiency

Using less energy to accomplish a given task, as for example, with new technology.


Designing and manufacturing more fuel-efficient automobiles.

Surface Water
Precipitation that remains on the surface of the land and does not seep down through the soil.
 The movement of fresh water from precipitation (including snowmelt) to rivers, lakes, wetlands, and ultimately, the ocean.
Watershed or drainage basin
A land are that delivers water into a stream or river system.
Underground caverns and porous layers of sand, gravel, or rock in which groundwater is stored.
Confined Aquifer

A groundwater storage area between impermeable layers of rock.


Is trapped and often under pressure.

Unconfined Aquifer
The layers of rock above are porous and allow surface water directly above them to seep downward, replacing aquifer contents.
Water table
The upper surface of the saturated zone of groundwater.
Food plain
The area bordering a river channel that has the potential to flood.
Saltwater intrusion

The movement of seawater into a freshwater aquifer located near the coast; caused when groundwater is depleted faster than it is replaced.



Reclaimed water
Treated wastewater that is reused in some way, such as for irrigration, manufacturing processes that require water for cooling, wetland restoration, or groundwater recharge.
Trickle irrigation

A type of irrigation that conserves water by piping it in to crops through sealed systems.


Pipes with tiny holds convery water directly to individual plants, right to the root system.

Gray water

Water that has already been usedfor a relatively non-polluting purpose, such as showers, dishwashing, and laundry.


Is not potable, but can be reused for toliets, plants, or car washing.

Desalinization: Distillation vs. Reverse osmosis

  1. Removal of salt from ocean or brackish water.
  2. Salt water is evaporated, and water vapor is condensed into freshwater (salt left behind).
  3. Involves forcing salt water through a filter permeable to water, but not salt.

The uppermost layer of Earth’s crust, which supports terrestrial plants, animals, and microorganisms.
Parent material

Rock that is slowly broken down due to the weathering processes.

Soil horizons
The horizontal layers into which many soils are organized, from the surface to the underlying parent material.
Nutrient cycling

The pathway of various nutrient minerals or elements from the environment through organisms and back to the environment.

  • Sand
  • Silt
  • Clay
  • Loam

Compare size of particles

  • Medium sized particles (.002 to .05 mm in diameter)
  • Small particles (less than .002 mm)
  • .002 mm or less, contain that greatest surface area of all soil particles
  • Ideal soil, 40% of each sand and silt, 20% clay

Degradation of once-fertile rangeland, agricultural land, or tropical dry forest into nonproductive desert.
Soil Salinization
The gradual accumulation of salt in a soil, often as a result of improper irrigation methods.
Crop rotation
The planting of a series of different crops in the same field over a period of years.

Strip Cropping

A special type of coutour plowing, produces alternating strips of different crops along natural contours.
Elements or compounds of elements that occur natrually in Earth’s crust.


Weathered particles that are transported by water and deposited as sediment on sea floor or shore.

Salts are left behind after water body dries up.


Responsible for deposits of table salt, gypsum.

Surface Mining

The extraction of mineral and energy resources near Earth’s surface by first removing te soil, subsoil, and overlying rock strata.

Subsurface mining
The extraction of mineral and energy resources from deep underground deposits.
The process in which ore is melted at high temperatures to separate impurities from the molten metal.

Piles of loose rock produced when a mineral such as uranium is mined and processed (extracted and purified from the ore).

Acid mine drainage
Pollution caused when sulfuric acid and dangerous dissolved materials such as lead, arsenic, and cadmium wash from mines into nearby lakes and streams.
Superfund site
Constructed wetlands

Way to restore mining land by trapping sediment and pollutants before they get into streams, improving water quality.



Way to restore mining land by use of specific plants to absorb and accumulate toxic materials in soil.
Mineral reserve
Mineral deposits that have been identified and are currently profitable to extract.
Mineral resources
Deposits that are potential sources, but are not currently profitable to extract.
Mineral reuse
Conservation of the resources in used itesm by using them over and over again.
Mineral recycling
Conservation of the resources in used items by converting them into new products.


The number, variety, and variability of Earth’s organisms.


Consists of three components: genetic diversity, species richness, and ecosystem diversity.


The elimination of species from Earth.
A species that faces threats that may cause it to become extinct with a short period.
Threatened Species
A species whose population has declined to the point that it may be at risk of extinction.
Background extinction
The continuous, low-level extinction of species that has occurred throught much of the history of life.
Mass extinction
The extinction of numerous species during a relatively short period of geological time.
Biodiversity hotspots
Relatively small areas of land that contain an exceptional number of endemic species and are at high risk from human activites.
Invasive species
Foreign species that spread rapidly in a new area where they are free of predators, parasites, or resource limitations that may have controlled their populations in the native habitat.
Biotic pollution

The introduction of a foreign species into an ecosystem in which it did not evolve.


Upsets the balance among the organisms live in that area and interferes with the ecosystem’s normal functioning.

Habitat fragmentation
The division of habitats that formerly occupied large, unbroken areas into smaller areas by roads, fields, cities, and other land-transforming zones.
Seed banks

Stored seeds that are safe from habitat destruction, climate warming, etc.


Seed banks can be used to reintroduce extinct plant species.

  1. Conservation biology
  2. in-sutu;conservation
  3. ex-sutu conservation

  1. The scientific study of how humans impact organisms and of the development of ways to protect bilogical diversity.
  2. On-site conservation, includes the establishment of parks and reserves.
  3. Off-site conservation, involves conserving in human made settings. ie- zoos

Restoration ecology
The study of the historical condition of a human-damaged ecosystem, with the goal of returning it as close as possible to its former state.
Derelict Land
Land area that was degraded by mining.