[cbloom]

It is expected that as a result of climate change, the permafrost in Siberia will thaw. This will release large amounts of methane into the atmosphere. Methane is a strong greenhouse gas, even stronger than carbon dioxide.
 
Question: is it theoretically possible to let methane and carbon dioxide react so that pure carbon and water are formed? (CO2+CH4 -> 2C+2H2O). If this could be done on a large scale, it could help solve the greenhouse gas problem.

If this is a stupid proposal/question (which is probably the case): I'm not a chemist, just a computer scientist from the Netherlands.

[Borek]

Unrealistic thermodynamically, doable only with additional energy (which we still mostly produce from burning fuels, thus producing additional CO₂).

[Corribus]

It's always a dangerous game predicting whether a reaction will happen just by looking at it, but in this case two things immediately jump out:

(1) Any reaction that involves taking a lot a gas to create less gas (or no gas, in this case) is going to be entropically unfavorable.

(2) If solid elemental carbon was easy to make, we maybe wouldn't be having so many wars over fossil fuels.

Which isn't to say this isn't possible. Plenty of unfavorable reactions are industrially important. If you find a way, share the secret. We will be rich