ATTN: the Sun has a larger effect on the Earth’s climate than anything else. Small changes in solar insolation due to variations in the Sun’s energy output or cyclical variations in the Earth’s orbit, known as the Milankovitch Cycles, can make a big difference in the surface temperature. Yes, greenhouse gasses, ocean currents, volcanic eruptions, and many other things can affect the climate, but the Sun is still the 800 lb. gorilla in the room. < >