
A view to the possible habitability of ancient Venus over three billion years [pdf] - bookofjoe
https://meetingorganizer.copernicus.org/EPSC-DPS2019/EPSC-DPS2019-1846-1.pdf
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fooblitzky
That Venus may once have had an Earth-like climate, until it hit a "runaway
greenhouse gas state", is a scary thought considering our current challenges
on Earth (and melting permafrost and methane bubbles). Sometimes people say
"we might pollute enough to kill all humans, but nature will continue just
fine without us." \- Unless we do enough damage to trigger a runaway state and
turn Earth into another Venus.

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opportune
Climate change is a big potential ecological disaster - for us. Earth has had
periods of much hotter temperatures than climate change is likely to induce.
During the early Carboniferous period, the average global temperature was
almost 10 degrees Celsius higher than today. It would take a long time to turn
Earth into Venus, or even something similar to the Carboniferous

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mikekchar
It's not clear to me that we understand the conditions under which the earth
was much hotter, or specifically what conditions resulted in cooler periods.
There was a article a few days ago discussing the theory that one of the ice
ages was caused by inter-planetary dust. This is an honest (and unpolitical)
question: how much do we know about these past climate changes are what caused
them?

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viach
It would be nice if a probe would find on Venus an ancient poster "Climate
change is not real, they all are lying to you!" or a record of an ancient
comic speech "It's only Venicians who have problem, Venus is going to be
fine".

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ant6n
I believe the Demonym for Venus is Venusian, or perhaps Cytherean. Venician
sounds like Venetian, that is, somebody from Venice.

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viach
You are probably right. I was going to use Venusian, but it sounds terribly
wrong to me, I can't explain why.

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cromwellian
A great sci-fi movie idea. In the far future, when Earth is suffering massive
effects from a 5-degree warming, NASA launches more probes to Venus. One
uncovers evidence that Venus not only once had life, but had civilization.
After studying large number of artifacts, it is found they too had a climate
crisis created by their civilization, one thats started with a run-away 6
degree rise, but failed to address it, which ultimately destroyed them.

The movie ends with a potentially gloomy message that we may already be too
late.

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01100011
A better movie: We use geoengineering to make Venus habitable and maintain
Earth's climate in its current state. We double the effective surface area of
the human race and all of Earth's species, while the idea of terraforming Mars
is reduced to a silly joke.

Instead of making a movie, we could actually do it. It sure beats the hell out
of Mars.

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mabbo
You'd need a heck of an umbrella to block all that sunlight. Seriously,
cooling it down via solar blockage is about the only way you could ever make
Venus livable. Followed by massive removal of CO2 on the now-icy surface.

Mars has the advantage that it's easy to make something hot- just use energy-
while making something colder is more complicated. Also- here me out here-
basketball on Mars will be _insane_. Venus still has, what, 80% of earth's
gravity? Boring.

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simcop2387
> You'd need a heck of an umbrella to block all that sunlight. Seriously,
> cooling it down via solar blockage is about the only way you could ever make
> Venus livable. Followed by massive removal of CO2 on the now-icy surface.

This is part of a plot point in Kim Stanley Robinson's Mars trilogy, definite
recommend if you want some reading about terraforming.

> Also- here me out here- basketball on Mars will be insane. Venus still has,
> what, 80% of earth's gravity? Boring.

Even better, lunar water polo.

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coolspot
> Major overturn events,or a proliferation of Large Igneous Provinces over
> millions of years could have turned Venus’ once stable temperate climate
> into the CO2dominated hot house of today.

[https://en.wikipedia.org/wiki/Large_igneous_province](https://en.wikipedia.org/wiki/Large_igneous_province)

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tabtab
There may be fossilized Sleestaks et al. ready for us to discover. However,
it's almost 900 degrees on the surface. Making a multi-day fossil-hunting bot
that can handle 900 degrees would be a huge technical feat: big AC with a
powerful/big fuel source.

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cwmma
the 'global resurfacing event' they refer to probably rules that out as
wikipedia describes this as '[covering] most or all of the planet with lava'

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cryptonector
I'm starting to get annoyed at papers like this that are all about
simulations. How is anyone to evaluate the paper without access to the models
and simulations? Archive that material or don't permit publishing.

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perl4ever
Seems like there are too many orders of magnitude more CO2 for Venus to be the
result of some sort of ecosystem issue, if it was originally like Earth.

It would have to be more like the entire crust and a substantial layer below
was turned over and combusted, wouldn't it?

And we know that Venus has a flagrantly unusual rotation.

So wouldn't the obvious explanation be a giant impact, with parameters that
didn't lead to a big moon like Earth's?

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sunstone
So if I'm not mistaken then it's likely that 3 billion years ago earth, mars
and venus all might have been suitable for sustaining life. A science fiction
work based on this premise could be interesting.

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jsingleton
Very readable two-pager. Not sure I like the styling of the graph though.

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lvoudour
It's itching me the wrong way as well. I prefer academic publications "dry"
and austere, keeping distractions at a minimum. Stylish, cutesy graphs are
better suited for other forms of dissemination

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HarryHirsch
It's a poster abstract, it's ephemeral, the piece research is waiting to be
written up and sent to a proper journal. Meanwhile, a scan of a quick sketch
is enough to get the point across.

