What would happen to humans if the sun's light was blocked from earth?
1 Answer
Life would pretty much cease to exist if the sunlight were blocked permanently. A temporary blockage would cause a serious setback to the biosphere, but it would recover.
Explanation:
In the past, volcanic eruptions have spewed huge amounts of ash in the atmosphere that temporarily cause a cooling of the planet and stop photosynthetic activity. Giant asteroid impacts can also have this affect. Since photosynthetic plants are the base trophic level, if they stop producing, the rest of the food web is in trouble.
In the recent past, these short-term volcanic events have led to starvation among humans if they go on long enough. Usually, the ash and soot eventually settle and photosynthesis kicks in again and life picks up. A permanent blockage of sunlight, or if our star went dark, would pretty much mean the end of life on Earth probably within a matter of years or decades (cave dwelling organisms and/or deep ocean critters that derive their energy from ocean volcanic vents might survive).
