What about the future evolution – the old age – of the Sun? About four billion years from now the Sun will be bright enough to cause significant increases in the surface temperature on Earth. The oceans will boil and carbon dioxide now present as carbonates in the sedimentary rocks will pour out into the atmosphere. This additional carbon dioxide will hold the heat inside the Earth’s atmosphere further increasing the temperature – an uncontrollable “greenhouse effect.” The Earth will become an uninhabitable oven.