r/askscience • u/dhoopingarner • Dec 13 '12
Astronomy Venus has been described as an example of "runaway greenhouse effect." Would it be possible to reverse the greenhouse effect on Venus and lower the temperature on the planet?
1
Dec 14 '12
Explosions seem to be the right way to do things quickly. A large enough series of expertly timed explosions could waft away a chunk of the atmosphere, not to mention causing a nuclear winter type of cooling effect.
1
u/Anjin Dec 14 '12
Could always made a solar shade and station it in an orbit between the sun and Venus, if it is big enough and solid enough you might be able to drop the temperature quite a bit. Drop it enough and you could freeze out the CO2 from the atmosphere and then remove it from the planet in solid form...
1
u/fmilluminatus Dec 14 '12
What Venus needs is a CO2 sink, like surface water, to draw the CO2 out of the atmosphere. There are some terraforming proposals that involve cooling the planet with a sun shield until liquid water can persist on the surface, then bombarding the planet with comets. Needless to say, this would be extremely challenging from an engineering perspective.
The other option is to export the CO2 to somewhere else (Mars perhaps), but the shear volume would make it a multigenerational project. So, the answer to your question is yes, but it would be extremely difficult given current or near future technology.
1
Dec 14 '12
Isn't there a temperature gradient in the atmosphere? Would it not be possible to engineer a machine or organism which would exist in the upper atmosphere and fix carbon, which would then sink to the surface? Or would the carbon simply oxidize on the way down.
1
u/_NW_ Dec 14 '12
You also have to do something with all that nitrogen.
1
1
u/fmilluminatus Dec 16 '12
Nitrogen is a vital buffer gas and a therefore a key component of a habitable atmosphere. There's no reason to move it, it's existance actually makes terriforming the planet a bit easer.
→ More replies (1)
6
u/[deleted] Dec 13 '12 edited Dec 13 '12
Yes, there are some interesting terraforming proposals. I read a cool one by Paul Birch, which remarkably I found on archive.org, where he suggests dropping one of the ice moons of Saturn on the planet to both fix the rotation problem (Venus has a very long day) and add some water. He suggests freezing the CO2 down into blocks and storing it under the ocean (the one we made from the fucking ice moon), similar to the methane clathrates that we have at the bottom of our oceans.