0 an increase in the amount of carbon dioxide and other gases in the atmosphere (= mixture of gases around the earth), that is believed to be the cause of a gradual warming of the surface of the earth
1 the gradual warming of the earth because of heat trapped by carbon dioxide and other gases in the atmosphere
2 an increase in the amount of carbon dioxide and other gases in the atmosphere (= mix of gases which surround the earth), which is believed to cause the surface of the earth to become gradually warmer and to be a threat to its future:
They claim that the floods are a result of the greenhouse effect.
As it rots, it releases carbon dioxide and methane, contributing to the greenhouse effect.
