The sun is the main sourse.
The sun is the ultimate source of energy for almost all earth ecosystems.
the sun
Solar energy.
The Sun
carbon
the sun
photosynthesis
The most important source off all is WATER!
The main source of energy is usually considered to be the energy absorbed from the sun (E.G., used in photosynthesis).
Heat from Earth's interior.
The sun.
The sun is the ultimate source of all energy in Earth's ecosystems.