What is Future of the Earth?
[[File:Red Giant Earth.jpg|right|thumb|250px|Drawing of the Earth after the Sun goes into the [[red giant]] phase, seven billion years from now.<ref name=apj418/>]] The '''future of the Earth''' will depend on many things, including increases in the brightness of the [[Sun]], loss of heat energy from the [[Earth]]'s core and change of the planet's orbit by the other things in the [[Solar System]]. The [[Milankovitch theory]] says the planet will continue to go into [[glaciation]] cycles because of the planet's difference in orbit from a perfect circle, the axis of the planet tilting, and pushing of the Earth's orbit. As part of the [[supercontinent cycle]], [[plate tectonics]] may create a [[supercontinent]] within 250 million–350 million years. Some time in the next 1.5 billion–4.5 billion years, the axis's tilt may begin to change into bad versions, with changes in the axis's tilt of up to 90°. One billion to two billion years in the future, the increase in [[solar radiation]] caused by the [[helium]] build-up at the core of the [[Sun]] will result in the loss of the oceans and the cessation of [[continental drift]]. Four billion years from now, the increase in the Earth's surface temperature will cause a bad [[greenhouse effect]]. By that point, most if not all the life on the Earth will be gone. The most likely fate of the planet is being destroyed by the Sun in about 7.5&nbsp;billion years, after the star has entered the [[red giant]] phase and expanded to cross the planet's orbit. ==Human influence== {{main|Conservation biology}} Humans now play a top role in the [[biosphere]], with the large amount of [[people]] in many of Earth's [[ecosystem]]s.<ref name=Mooney/> This has caused a widespread, ongoing [[extinction]] of other [[species]] known as the [[Holocene extinction]]. The Holocene extinction event is the result of [[habitat destruction]], the large distribution of [[invasive species]], hunting and [[climate change]].<ref name=cowie07/><ref name=nature04/> ==Solar evolution== {{seealso|Stellar ev