Global Warming

Merriam Webster
adjective. glob·al \ˈglō-bəl\ noun. warm·ing \-ˈwȯr-miŋ\
An increase in the earth’s atmospheric and oceanic temperatures widely predicted to occur due to an increase in the greenhouse effect resulting especially from pollution.

Urban Dictionary
An increase in the average temperature of the earth’s atmosphere, especially a sustained increase sufficient to cause climatic change.