Here's why:
* Photosynthesis: Plants and other photosynthetic organisms use sunlight to convert carbon dioxide and water into glucose (sugar) and oxygen. This process is called photosynthesis and is the foundation of almost all food chains on Earth.
* Energy Transfer: The glucose produced by photosynthesis serves as a source of chemical energy for the plant itself and for all the organisms that consume it.
* Food Webs: Energy flows through food webs as organisms consume other organisms. This energy ultimately comes from the sun through the process of photosynthesis.
Therefore, the sun's energy, captured by photosynthetic organisms, is the ultimate source of energy for life on Earth.
