The life and death of planet Earth
Planet Earth is middle-aged. Science has worked hard to piece together the story of the evolution of our world up to this point, but only recently have we developed the understanding and the tools to describe the entire life cycle of a planet. Ward and Brownlee, a geologist and an astronomer respectively, combine their knowledge of how the critical sustaining systems of our planet evolve through time with their understanding of the life cycles of stars and solar systems, to tell the story of the second half of Earth's life. The process of evolution will essentially reverse itself: life as we know it will subside until only the simplest forms remain. Eventually, they too will disappear. The oceans will evaporate, the atmosphere will degrade, and, as the sun slowly expands, Earth itself will eventually meet a fiery end. --From publisher description.
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What Hacker News says
- Yes, it is. There was a pop-sci book that came out twenty years ago, The Life and Death of Planet Earth, which contains some speculation about the consequences of this: https://en.wikipedia.org/wiki/The_Life_and_Death_of_Planet_E.... They give a low-end estimate of 500-800 million years before plate tectonics stop. Net effect would be the planet becomes uninhabitable by modern day plants and animals well before the sun goes red giant and kills off everything else.
- Not a "few" hundred million years, but less than a billion years:
https://en.wikipedia.org/wiki/Timeline_of_the_far_future#Ear...
500-600 million years: The Sun's increasing luminosity begins to disrupt the carbonate–silicate cycle; higher luminosity increases weathering of surface rocks, which traps carbon dioxide in the ground as carbonate. As water evaporates from the Earth's surface, rocks harden, causing plate tectonics to slow and eventually stop once the oceans evaporate completely. With less volcanism to recycle carbon into the Earth's atmosphere, carbon dioxide levels begin to fall. By this time, carbon dioxide levels will fall to the point at which C3 photosynthesis is no longer possible. All plants that use C3 photosynthesis (≈99 percent of present-day species) will die.
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800-900 million years: Carbon dioxide levels will fall to the point at which C4 photosynthesis is no longer possible. Without plant life to recycle oxygen in the atmosphere, free oxygen and the ozone layer will disappear from the atmosphere allowing for intense levels of deadly UV light to reach the surface. Animals in food chains that were dependent on live plants will disappear shortly afterward. At most, animal life could survive about 3 to 100 million years after plant life dies out. Just like plants, the extinction of animals will likely coincide with the loss of plants. It will start with large animals, then smaller animals and flying creatures, then amphibians, followed by reptiles, and finally, invertebrates. In the book The Life and Death of Planet Earth, authors Peter D. Ward and Donald Brownlee state that some animal life may be able to survive in the oceans. Eventually, however, all multicellular life will die out.
