greenhouse gas

noun

Definition of greenhouse gas

: any of various gaseous compounds (such as carbon dioxide or methane) that absorb infrared radiation, trap heat in the atmosphere, and contribute to the greenhouse effect Water vapor is an important gas for the study of climate and weather because of its role as a natural greenhouse gas as well as its relationship to clouds and precipitation. —Mohi Kumar Scientists now recognize tropospheric ozone—a component of smog—as a greenhouse gas as well as an eye and lung irritant. —Science News While it may not be possible to eliminate all greenhouse gas emissions, it is possible to offset some of the emissions that do still occur. Offsetting involves supporting projects that reduce or sequester greenhouse gas emissions in another location. —Tyson Miller Livestock emit 14.5 percent of all greenhouse gas emissions each year. Most of that is from cows. —Marley Walker