<P> A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about − 18 ° C ( 0 ° F ) , rather than the present average of 15 ° C ( 59 ° F ) . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect . </P>
<P> A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about − 18 ° C ( 0 ° F ) , rather than the present average of 15 ° C ( 59 ° F ) . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect . </P>
what are the two most abundant greenhouse gases in the earth 's atmosphere
what are the two most abundant greenhouse gases in the earth 's atmosphere
water vapor , carbon dioxide
water vapor , carbon dioxide