How the sun's energy is utilized on earth and in the biosphere. Start studying Chapter 1: Energy in the Biosphere. Why is sunlight important? Sun is the source of How much of the sun's energy reaches Earth each day?. Sunlight is important for the biosphere because it is the basis of almost all food chains on Earth. With the exception of the deep ocean, all life on Earth depends. The Sun Doesn't Cause Skin Cancer, But Sunscreen Does! Biosphere: Biosphere, relatively thin life-supporting stratum of Earth's surface, Energy from the Sun relentlessly bombarded the surface of the primitive Earth, and in . through which the energy and nutrients necessary for life flow and cycle . How the sun's energy is utilized on earth and in the biosphere. Sunlight is the essential "ingredient" to photosynthesis in which plants make oxygen, without sunlight photos. could not occur, and would, over.