Earth's temperature depends on the balance between energy entering and leaving the planet's system. ... Variations in the sun's energy reaching Earth. Changes in the reflectivity of Earth's atmosphere and surface. Changes in the greenhouse effect, which affects the amount of heat retained by Earth's atmosphere.
There can be many caused to the change of Earths temperature but one would be the use of fossil fuels. This is because when burned it releases Greenhouse gasses which are trapped in the atmosphere and causes heat. Which eventually leads to Global Warming. (Hopes this helps! )
