Here's why:
* Photosynthesis is the process by which plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of glucose. This glucose is then used as a source of energy for the organism, and can also be stored for later use.
* All other organisms rely on the energy produced through photosynthesis, either directly by eating plants or algae, or indirectly by eating animals that have consumed plants or algae.
* Without photosynthesis, life on Earth as we know it would not exist.
While other energy sources like geothermal energy exist, they are not as crucial for the vast majority of life on Earth.
