[gus_massa]

The amount of water in the air is almost impossible to change because the evaporation and condensation keep the balance "constant". It actually depends on the average temperature and other factors so it's not a real "constant", but unless it's possible to cover all the seas it's impossible to reduce it.

The amount of CO2 changes more slowly, plants and cyanobacteria and some minerals absorb it, but it's a slow process. Natural decomposition, fires and fossil fuel power plants release it, but it's a slow process.

So it's easy to modify the CO2 amount in either direction. Burning fossil fuel to produce energy makes a lot of money. Carbon capture requires a lot of money. So you can guess which one is wining now.