I'm still not convinced that it would be a good idea. I'm not comfortable with the idea of trying to cover up warming caused by human emissions with even more emissions. Reduction of emissions is the only answer I agree with -- which capturing and this covering do nothing to encourage.

Clouds also help to trap heat near the ground, which is partially why the coldest days up here started on the clearest days. As such, any cooling caused by increasing the amount of water vapour in the atmosphere would be temporary at best and in the long run would be quite detrimental indeed.