What is the main source of Earth’s energy?
The Sun is the major source of energy for Earth’s oceans, atmosphere, land, and biosphere. Averaged over an entire year, approximately 342 watts of solar energy fall upon every square meter of Earth. The luminosity of the Sun is about 3. This is the total power radiated out into space by the Sun. Most of this radiation is in the visible and infrared part of the electromagnetic spectrum, with less than 1% emitted in the radio, UV and X-ray spectral bands.