What is a gradual increase in average global temperature

The gradual increase in the average temperature of the planet is called "global warming." Global warming is the term used to described the phenomena of rising planet temperatures that is the result of the greenhouse effect and other factors largely shown to be the result of human activity and release of greenhouse gases such as Co2 and Methane that are impacting the atmosphere and raising the planet's temperature.

Gradual increase in global temperature is called global warming