The world's major source of energy comes from?
Fossil fuels are the world's major source of energy.
Herbivores are the dominant species on Earth so plants are the major source of energy next to an Omnivores diet of meat and plants. The plant process is photosynthesis and that's where the energy for an ecosystem comes from. To sum up, the sun is the source of energy for the majority of ecosystems as sunlight is required for photosynthesis.