All scientists agree that life will not always exist on earth, since the sun will end up exhausting its fuel and destroy the earth next to it. Plants will have difficulty surviving as CO2 levels decrease, since they depend on this gas to produce food. Subsequently, terrestrial and oceanic creatures would die hunger if the plants stop producing oxygen. In addition, methane concentrations would begin to increase, accelerating the disappearance of organisms that breathed oxygen. Finally, they would only remain in the earth microscopic bacteria that do not need oxygen to survive.