Which is the more powerful greenhouse gas water or CO2?

Question

If we move to a Hydrogen based economy and cut down our carbon emisions will we make the greenhouse problem worse by realeasing so much more water vapour into the atmosphere?

Answer 1

From wikipedia:
"Water vapor is a natural greenhouse gas and accounts for the largest percentage of the greenhouse effect. Water vapor concentrations fluctuate regionally, but human activity does not directly affect water vapor concentrations except at very local scales."
But your question is a good one becuase this effect alone make prediction impossible and so in my opinion there is a lot of hype for very little scientific basis. I don't believe the water created by hydrogen cars will amount to much. The hydrogen still needs to be created and that generally takes power

Answer 2

If we use hydrogen, the most likely source will be electrolysis of water, splitting the two hydrogen atoms off from their oxygen. When we burn the hydrogen, it combines with free oxygen to make water again. We have therefore contributed no more water to the system than was there in the first place.

However, that aside, although water vapour has a very powerful greenhouse impact, whereas we can go on adding methane and CO2 almost indefinitely, there is a limit to how much water the atmosphere can hold; too much, and it just condenses and falls as rain or snow.

Answer 3

water is not a greenhouse gas. CO2 and methane are the 2 worst greenhouse gasses

Answer 4

I don't think water vapour is a green house gas, in fact there was an unproven theory that it reflects heat of the sun.

so the answer is CO2

Answer 5

water isn't a green house gas but it might give us more rain

Answer 6

CO2

Worst is methane no water

Answer 7

Co2 by far more harmful.