How does the sun help sustain life on earth and how is this related to the earth's natural greenhouse effect?

The sun lights and warms the planet. Greenhouse gases in the atmosphere retain this heat to allow life on earth. The greenhouse effect is driven by the carbon cycle.

The sun supports photosynthesis, the process used by green plants and some bacteria to make compounds such as carbohydrates. The sun powers the cycling of matter, it also drives the climate and weather systems that distribute heat and fresh water.