

The Gaia Hypothesis Is Still Giving Us Feedback - dnetesn
http://nautil.us/issue/12/feedback/the-gaia-hypothesis-is-still-giving-us-feedback?utm_source=tss&utm_medium=desktop&utm_campaign=linkfrom

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phkahler
>> Water vapor is a greenhouse gas that helps to warm Earth’s surface. Its
concentration in the atmosphere increases with surface temperature; hence,
warmer surface temperatures lead to more water vapor, which in turn leads to
warmer temperatures—a positive feedback loop. Conversely, colder surface
temperatures should lead to less water vapor, and to even colder temperatures.
So the water vapor feedback makes the faint young sun problem worse, not
better.

But what about cloud formation? When there is enough water vapor you get more
cloud formation, which reflects more sunlight (and traps heat underneath). So
that's a positive feedback bringing the temperature up and then clouds forming
to stabilize it at the point where weather becomes interesting.

Once again, I hate the hand waving ideas without simulations - there are
problems with both his and mine.

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snowwrestler
IIRC, cloud formation is one of the most, if not the most, difficult things to
simulate in global climate models. The last time I looked in detail, I believe
most models included cloud cover as tunable parameters.

Clouds can have a cooling or warming effect depending on their characteristics
--persistence, cover, thickness, altitude, etc.

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WD-42
And then we have all the mass extinctions that have happened throughout the
earth's lifespan. In fact the largest known extinction event, the
Permian–Triassic, which wiped out something like 94% of all organisms, was
caused mostly by "natural" causes - not an asteroid impact or something
external. Gradual climate change, a runaway greenhouse effect, and poisonous
gas farting bacteria were thought to be the cause. No, earth is not a haven
for life. It's a great place for life to thrive, but it doesn't care about
life.

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hcarvalhoalves
> No, earth is not a haven for life.

Louis C.K. disagrees better than I could: "this is Earth, and for trillions of
miles in every direction it _fucking sucks so bad_ ".

[https://www.youtube.com/watch?v=43vjEiFckbw](https://www.youtube.com/watch?v=43vjEiFckbw)

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WD-42
Pfft, a trillion miles is roughly a 1/5 a lightyear. If it only sucks for a
trillion miles, that's not so bad. Our home galaxy alone is 100,000 light
years across. And there are hundreds of billions more of them. Its like saying
the movie sucks because the guy sitting in front of you is too tall.

