The greenhouse effect is earths atmosphere being polluted by gasses that prevent heat from escaping as easily causing earth's temperature to rise and if that didnt exist earth would probably be alot cooler.
Impact and pressure of material by gravity and this compression produces components crashing into one another and along these lines generation of tremendous measure of energy.
The second procedure that was likewise in charge of the generation of heat during the formation of the earth is the crash of earth with meteors and space rocks which was exceptionally visit during earth early history and the dynamic vitality of these bodies gets changed over into the heat energy during the impact.
