Editing Earth (section)

=== Future ===
{{Main|Future of Earth}}
{{See also|Global catastrophic risk}}
[[File:Red Giant Earth warm.jpg|thumb|upright=1.3|alt=A dark gray and red sphere representing the Earth lies against a black background to the right of an orange circular object representing the Sun|Conjectured illustration of the scorched Earth after the [[Sun]] has entered the [[red giant]] phase, about 5–7&nbsp;billion years in the future]]
Earth's expected long-term future is tied to that of the Sun. Over the next {{val|1.1|u=billion years}}, solar luminosity will increase by 10%, and over the next {{val|3.5|u=billion years}} by 40%.<ref name="sun_future" /> Earth's increasing surface temperature will accelerate the [[carbonate–silicate cycle|inorganic carbon cycle]], possibly reducing {{chem2|CO2}} concentration to levels lethally low for current plants ({{val|10|ul=ppm}} for [[C4 carbon fixation|C<sub>4</sub> photosynthesis]]) in approximately {{val|100|–|900|u=million years}}.<ref name="britt2000" /><ref name="pnas1_24_9576" /> A lack of vegetation would result in the loss of oxygen in the atmosphere, making current animal life impossible.<ref name="ward_brownlee2002" /> Due to the increased luminosity, Earth's mean temperature may reach {{convert|100|C|F|0|abbr=}} in 1.5&nbsp;billion years, and all ocean water will evaporate and be lost to space, which may trigger a [[runaway greenhouse effect]], within an estimated 1.6 to 3&nbsp;billion years.<ref name="Mello-2020">{{Cite journal
|last1=Mello |first1=Fernando de Sousa |last2=Friaça |first2=Amâncio César Santos |date=2020 |title=The end of life on Earth is not the end of the world: converging to an estimate of life span of the biosphere? |journal=International Journal of Astrobiology |language=en |volume=19 |issue=1 |pages=25–42 |doi=10.1017/S1473550419000120 |bibcode=2020IJAsB..19...25D |issn=1473-5504 |doi-access=free}}</ref> Even if the Sun were stable and eternal, a significant fraction of the water in the modern oceans would descend into the [[Mantle (geology)|mantle]], due to reduced steam venting from mid-ocean ridges as the core of the Earth slowly cools.<ref name="Mello-2020" /><ref name="hess5_4_569" />

The Sun will [[stellar evolution|evolve]] to become a [[red giant]] in about {{val|5|u=billion years}}. Models predict that the Sun will expand to roughly {{convert|1|AU|e6km e6mi|lk=in|abbr=unit}}, about 250 times its present radius.<ref name="sun_future" /><ref name="sun_future_schroder" /> Earth's fate is less clear. As a red giant, the Sun will lose roughly 30% of its mass, so, without tidal effects, Earth will move to an orbit {{convert|1.7|AU|e6km e6mi|lk=off|abbr=unit}} from the Sun when the star reaches its maximum radius, otherwise, with tidal effects, it may enter the Sun's atmosphere and be vaporized, with the heavier elements sinking to the core of the dying sun.<ref name="sun_future" />