Good news-we have extra time before the Sun ends life on Earth

Key Points:

• A new study using a 3D climate model estimates that complex life on Earth, particularly land plants, could survive for up to 1.9 billion more years despite the Sun’s gradual brightening and eventual transformation into a red giant.
• The study explores two scenarios: one where strong silicate weathering acts as a thermostat lowering CO2 levels, and another where weak weathering allows temperatures to rise, both ultimately limiting plant survival due to either heat stress or CO2 starvation.
• In the weak weathering scenario, land plants face extinction between 1.68 and 1.87 billion years due to high temperatures, while in the strong weathering scenario, CO2 levels drop below the threshold for most plants between 1.35 and 1.64 billion years.
• Some resilient plants and marine life might extend their survival slightly longer by utilizing bicarbonate, potentially lasting until about 1.84 billion years from now.
• These findings are more optimistic than previous estimates, highlighting that evolutionary adaptations and potential geoengineering could further extend the habitability of Earth, and offering insights into the temporal window for life on exoplanets.