A Nap vörös óriássá alakulása miatt hány millió év múlva lesz lakhatatlan a Föld?

1 milliárd, és még nem lesz vörös óriás.

Csak a víz forr el a Földön.

Már persze akkor, ha addig az emberiség meghülyül, és háborúzik.

"500–600 million (years)

...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 utilize C3 photosynthesis (≈99 percent of present-day species) will die. The extinction of C3 plant life is likely to be a long-term decline rather than a sharp drop. It is likely that plant groups will die one by one well before the critical carbon dioxide level is reached...

500–800 million

...The death of most plant life will result in less oxygen in the atmosphere, allowing for more DNA-damaging ultraviolet radiation to reach the surface. The rising temperatures will increase chemical reactions in the atmosphere, further lowering oxygen levels...

1.1 billion

The Sun's luminosity has risen by 10%, causing Earth's surface temperatures to reach an average of around 320 K (47 °C; 116 °F). The atmosphere will become a "moist greenhouse", resulting in a runaway evaporation of the oceans. This would cause plate tectonics to stop completely, if not already stopped before this time. Pockets of water may still be present at the poles, allowing abodes for simple life

1.3 billion

Eukaryotic life dies out on Earth due to carbon dioxide starvation. Only prokaryotes remain

1.5–1.6 billion

The Sun's rising luminosity causes its circumstellar habitable zone to move outwards; as carbon dioxide rises in Mars's atmosphere, its surface temperature rises to levels akin to Earth during the ice age

2.8 billion

Earth's surface temperature reaches around 420 K (147 °C; 296 °F), even at the poles

All life, which by now had been reduced to unicellular colonies in isolated, scattered microenvironments such as high-altitude lakes or caves, goes extinct"

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