Solar energy is critical to the survival of every living organism on Earth. Nobody would be alive, not me or you or any plant or animal, if the sun suddenly stopped burning. Plankton, one of the smallest, most simple forms of life on this planet, must have solar energy to develop and live. Most people would agree that the first organisms to die would be plant life if we ran out of solar energy, because they utilize photosynthesis. Without any plants, there goes all the animals, from the simplest forms on up to the most complex, humans. So while we may not absorb light energy directly like the plants on our planet, we are still indirectly dependent on solar energy from the sun.