What is the earth's main source of energy?

The Sun is the earth's main source of energy because it provides sunlight, which is essential for photosynthesis in plants. This process allows plants to convert sunlight into chemical energy, forming the basis of the food chain. Additionally, sunlight influences weather patterns and drives the water cycle, impacting ecosystems globally.

Without the Sun’s energy, life on Earth as we know it would not be sustainable, as it supports both plant and animal life. Other energy sources, such as wind and geothermal energy, derive energy from the Sun either directly or indirectly but do not provide the primary energy input to the Earth's systems. Thus, the Sun stands as the foundational energy source for our planet.