hydrogen cells

[1animal2]

a little concern i have about hydrogen cells! these are meant to be the fuel of the future especially for cars. they are meant to be a clean renewable power source. to my knowledge they combine hydrogen and oxygen to create water vapour. just i vaguely remember reading somewhere that water vapour is the most potent greenhouse gas of the lot and that the reason one of the planets in our solar system(forget which one)is so hot is mainly due to water vapour creating a runaway greenhouse effect!
can anyone tell me if this is correct and also if hydrogen cells is a technology the powers that be are still concentrating on developing?
thanks

[Gef]

Sine the hydrogen is produced from water in the first place there will be no overall effect. Hydrogen cell technology is something for the future but the problem is that it needs electricity to produce the hydrogen.

[brachiopod]

If that were the case, then the fact that that two thirds of this planet's surface is water, means we''d be totally forked - hydrogen cell or no hydrogen cell.

[Loosehead]

Water vapour is not the most "Potent" green house gas. The runaway greenhouse to which you refer is on Venus. The clouds of Venus are mostly sulphuric acid. The sun's heat is trapped and kept in, hence Venus is the hottest planet even though it is not the closest. Someone else can go into how it got that way!

[jake-the-peg]

As Loosehead says water vapour is a greenhouse gas. It's complicated but if the atmosphere becomes too saturated with water vapour you get rain and there's less water vapour in the atmosphere.

Unfortunately as the temperature rises the atmosphere's capacity to store water vapour rises. Some believe Venus' water contributed to it's current state:
http://www.astro.washington.edu/larson/Astro15 0b/Lectures/Venus/venus.html#atmosphere


Remember that as well as CO2 fossil fuels also produce water vapour now. and although I don't have the figures to hand I'd imagine that human production of water vapour is likely to be nothing compare to a warm day over the Pacific.

Even so hydrogen is by no means a shoe-in for the fuel of the future role. There are a lot of storage and safety questions that need good answers and it faces strong competion from battery technology at the low end.

In other words I could imagine a world with cars running on battery power by not container ships doing the same.

[jimmy654]

http://www.futurecars.com/futurecars/hydrogen_ fuellcell_cars1.html