Eternal rainfall
There’s a popular cliché in noir and science fiction: it’s always raining. But might that not become a reality in the future?
Our cars are currently putting greenhouse gases in the atmosphere, heating it up. Advocates of hydrogen power claim that the only thing coming out of the muffler of a hydrogen car will be clean water vapor. Isn’t that actually worse?
This water vapor will increase atmospheric humidity. When this goes up, the likelihood of rainfall increases. So we’d be replacing the smog clouds of today with rainclouds and constant rainfall? Woohoo?
Add to that that water vapor is also a greenhouse gas, and an increase in it should raise temperature and maybe create more water vapor.
But maybe water vapor from humanity is really small enough to be ignored, compared to the huge natural sources of water vapor? Like the sea, or so.
Hmm… wikipedia has a note on water vapor, and it says predictions are that actual relative humidity will remain nearly constant: http://en.wikipedia.org/wiki/Greenhouse_gas#The_role_of_water_vapor
Water evaporates into water vapor quite slowly. As opposed to an engine that forcefully creates water, heats it into steam, and pushes it out the muffler.
As a result of your post, sir, I’ve just bought shares in an umbrella manufacturer. Hooray!
If your investment bombs, please don’t sue me.