People think Earth dies when the Sun becomes a red giant in five billion years — the more likely end is a billion years from now, when a star already 30 percent brighter than at birth pushes CO₂ too low for C3 plants, then a moist greenhouse strips the oceans of hydrogen and leaves a sterile Venus

People think Earth dies when the Sun becomes a red giant in five billion years — the more likely end is a billion years from now, when a star already 30 percent brighter than at birth pushes CO₂ too low for C3 plants, then a moist greenhouse strips the oceans of hydrogen and leaves a sterile Venus

The popular ending is fire. The actual ending is a slow loss of air that plants can breathe, then of water that can come back.