gas - natural gas, used as fuel.

gasoline - petroleum fuel, used to power cars, trucks, lawn mowers, etc.

geothermal - literally, heat from the earth; energy obtained from the hot areas under the surface of the earth.

gillnets - walls of netting that are usually staked to the sea floor. Fish become entangled or caught by their gills. (See also driftnets).

global warming - increase in the average temperature of the earth's surface.

Golden Carrot - an incentive program that is designed to transform the market to produce much greater energy efficiency. The term is a trademark of the Consortium for Energy Efficiency.

grassroots - local or person-to-person. A typical grassroots effort might include a door-to-door education and survey campaign.

grazing - the use of grasses and other plants to feed wild or domestic herbivores such as deer, sheep and cows.

green design - a design, usually architectural, conforming to environmentally sound principles of building, material and energy use. A green building, for example, might make use of solar panels, skylights, and recycled building materials.

greenhouse - a building made with translucent (light transparent, usually glass or fiberglass) walls conducive to plant growth.

greenhouse effect - the process that raises the temperature of air in the lower atmosphere due to heat trapped by greenhouse gases, such as carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and ozone.

greenhouse gas - a gas involved in the greenhouse effect.

greenway - undeveloped land usually in cities, set aside or used for recreation or conservation.

groundfish - a general term referring to fish that live on or near the sea floor. Groundfish are also called bottom fish or demersal fish.

groundwater - water below the earth's surface; the source of water for wells and springs.

growth overfishing - the process of catching fish before they are fully grown resulting in a decrease in the average size of the fish population.