I wish we would plan ahead and try a solar shield at L1. If we cooled the planet sufficiently, the CO2 would solidify and we could get to work processing it. Venus is far more interesting than the dusty little rock we keep probing. Sure, it may take a millenium, but the sooner we start, the sooner we finish.
Here's an excerpt from the wikipedia page ( https://en.wikipedia.org/wiki/Terraforming_of_Venus )
Difficulties include the fact that the production of organic molecules from carbon dioxide requires hydrogen, which is very rare on Venus. Because Venus lacks a protective magnetosphere, the upper atmosphere is exposed to direct erosion by the solar wind and has lost most of its original hydrogen to space.
Venus has a magnetosphere, although not as strong as Earth's. The problem with Venus' atmosphere, AFAIK, is that the heavier carbon dioxide layer is so thick that reaches the limit of that magnetosphere and in doing so it pushes the lighter molecules like hydrogen or even water to be exposed to the mentioned solar wind. If enough of that atmospheric carbon gets somehow fixated, then the freed oxygen should act as a capture net for all the solar wind's incoming protons and form water molecules (which, being heavier than oxygen, should then sink into lower atmospheric layers).
P.S.: I assumed only "enough" of carbon taken out of the atmosphere, so enough carbon dioxide should be assumed as left there untouched, which now with newly available water molecules should result in bicarbonate, carbonic acid, and other goodies, thus preserve Venus' traditional acidic environment, so no worries there! ;)
For technology with uncertain results and uncertain resource requirements, this does not follow. It may well be that any effort we spend today is entirely wasted 100 years from now.
We (any/all nations of humanity) don't really have much of a space presence, let alone industry. If we did, I think we'd first build solar array, around earth, to help our energy shortage; I'm not sure we have a space shortage, so Venus doesn't really solve any current problems.
Maybe we can find a light gas that could form a thin layer in the upper Venus atmosphere to change its reflective profile?
The great thing about a solar array in space is it can be in sunlight 100% of the time, without needing to change orientation, and the shadow it casts needn't be on earth (i.e. nothing is deprived of sunlight).
The difficulty is that since the earth spins, and we couldn't beam down to the same location, so maybe we'd need an array of geo-statically orbiting beam relay stations to switch between.
so nothing will be practically solved with a sun heat shield, we need to find a way to break the CO2 somewhat quickly
but then we have the same challenge here on Earth....
It did not, so far as we can tell, get blasted by a Mars-sized proto-planet like Earth did, which made the Moon and entirely re-melted Earth, so probably got a good head start on breeding life. But maybe Earth's plate tectonics came from that event, too.
AIUI, our Moon is also the reason we are not tidally -almost- locked to the sun, with a permanent equatorial 250 mph wind.
I feel like even if Venus had Earth-like atmosphere it'll still be hard for life to endure the 121-day long "day" and "night" where temperature would go from like 250°C to -250°C (numbers from the top of my head). Maybe only on poles there would be possible for water to stay in liquid form for long enough so that life could emerge.
Mars and Ceres get a pass being far from the sun and close to Jupiter. Earth gets a pass because it has a massive moon keeping things stirred up. Venus, like Mercury, is not quite locked. As your rotation period gets close to your orbital period, tidal forces are much reduced. Venus could be oscillating around a resonant point, not yet settled into it.
Temperature difference between day and night cannot be large with a 250 mph global wind keeping the atmosphere well-stirred. Under an ocean, life would be further protected from temperature extremes, with high wind performing evaporative cooling on the day side, and surface ice insulating on the night side.
It could. On the other hand Earth could become the next Venus, if climate change runs out of control. No?
For one, Earth is much further away.
But most importantly, we have no clue if our current carbon levels are any sort of maxima in regards to what the planet can handle. We just have our own little recent industrialized history, and some charts about the past that are, at best, educated guesses.
As George Carlin would say, "The planet will shake us off like a bad cold"
Climate change is more important for our species survival much more so than the planet. The planet will be fine. The planet will recover after we're gone.
Comedians such as Carlin were highly intelligent, part of what made their genius. His jokes are typically funny because they contain much truth that otherwise few others would say.
Look at how:
- no other earth based space faring civilization has evolved before us.
- other intelligent species do not seem well equipped to do so, as it's hard to evolve tools without hands / prehensile organs (cetaceans), or when your lifespan is short or you're not social (octopuses & squids).
- we used up pretty much all easily accessible fossil fuels for our industrial revolution and they may take hundreds of millions of years to reconstitute, and it's unclear if anyone could evolve an industrial civilization without that kickstart of easy energy.
It's far from certain that if we disappear earth will get another good shot at evolving a space faring civilization before it's too late.
Just because we were the first doesn't mean we'll be the last. A billion years is a very very very long time, and there are multiple billions of years in the Earth's future.
I don't understand what you mean about it having been in full swing for a century before that.
needs citation
The article mentions massive amounts of C02 released 500 million years ago by volcanic activity in the Siberian Traps. The dinosaurs evolved on an Earth with six times the amount of C02 in the atmosphere we have today. So we're nowhere near a maxima. It's just a question of how difficult climate change will be for our civilization and parts of the biosphere we rely on.
However I don't know about the microbes, i fear that they might get killed at an average temperature of 737 K (464 C).
https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.htm... https://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.ht...
If you are interested in learning more on hypothetical approached of terraforming Venus, I suggest reading this Wiki article: https://en.wikipedia.org/wiki/Terraforming_of_Venus#Biologic...
The upside is, of water aka H2O that we need, the 2 H atoms are the lighter component, specifically:
2H = 2 * 1.67 * 10(-24) grams 1O = 1 * 2.65 * 10(-23) grams
So hydrogen is 11% of water, and oxygen is 88%;
meaning every kg hydrogen can combine with 8kg oxygen to give 9L water.
So all the Oxygen already being there (in CO2) is good.
Early stage terraforming need not be too fussed about collateral damage from multiple extinction-events (and the footage I presume would be spectacular).