Naked Science: Snowball Earth (15 of 24)

Naked Science: Snowball Earth

Two billion years ago, Our sun was weaker.
Our planet Relied on greenhouse gases like Carbon dioxide and methane to Maintain its temperate climate.
But photosynthesis uses up Carbon dioxide.
It also produces Oxygen, which destroys methane.
The result: a double-whammy.
Levels of both these vital Levels of both these vital greenhouse gases plummeted.
you have a precarious Situation.
You have a planet That's greenhouse needs methane And you suddenly evolve a bug That destroys the methane.

maybe the first bacteria that Photosynthesised crashed the Carbon dioxide and methane from The atmosphere and triggered The atmosphere and triggered the first snowball earth.
[narrator]: as oxygen Production soared, methane Levels tumbled.
With the loss of That greenhouse gas, the earth Spiralled into a deep freeze.
It 's kind of a frightening Conclusion that a single celled Mutant bug destroyed an entire Planetary ecosystem.
Destroyed it.
Turned it into A snowball for perhaps 35 to 100 million years.
[narrator]: some scientists Now think that our planet has Been encased in ice on at least Three separate occasions.
And each time, under different Circumstances.
But these Snowball earth scenarios present A huge problem: if our planet Was trapped in ice, how did it Ever escape?
Something must have Ever escape?
Something must have caused a global meltdown.
Evidence of the thaw is right Here.