Hydrogen cars - will it really reduce greenhouse emittions?

[Darwin420]

I have been thinking about this for a while. People say that Hydrogen fuel cells will be the new technology that will reduce greenhouse gases, thus, prevent global warming from getting a lot worse.

Here is what I have been thinking if the hydrogen fuel cell works like this:

hydrogen + oxygen ---> water vapor + electricity

and considering the fact that water vapor is one of the top greenhouse gases next to carbon dioxide, wouldn't this new "break through technology" be doing the exact same thing to our environment?

It is analogous, if everyone substituted cars ran by gas with cars with hydrogen, the same effect would happen to the environment. Or would it?

But then again this is a very simplistic idea, and it boggles my mind no one has mentioned it, so most likely, there is a reason why no one mentioned it.

The only other thing I can think of that would might prevent this technology from doing the same thing that current cars do, is that the water is put back into the hydrogen cycle.

But really, I do not know, any ideas folks?

[mith]

Oh it's simple

cars using hydrogen = cars not using petroleum = less emission of carbon.

Assuming it takes millions of years to remake petroleum(I guess we're disgregarding plant carbon fixation)whereas the hydrogen production cycle is much faster(synthetic methods) you'll have less buildup of gases.

Of course this is all baloney if people decide to drive more because it is less polluting. You're still gonig to be using resources to produce the hydrogen.

[Darwin420]

Oh it's simple

cars using hydrogen = cars not using petroleum = less emission of carbon.

Assuming it takes millions of years to remake petroleum(I guess we're disgregarding plant carbon fixation)whereas the hydrogen production cycle is much faster(synthetic methods) you'll have less buildup of gases.

Of course this is all baloney if people decide to drive more because it is less polluting. You're still gonig to be using resources to produce the hydrogen.

I see what you are saying, and I understand that. However, when you say cars using hydrogen = less emissions of carbon, that is absolutely correct. BUT, that is not my point - hydrogen cars still emit green house gases (water vapor), and if everyone switches to hydrogen cars, we are going to have a similar problem. I did not look at the average emittion of water vapor from these cars, but I am sure they emit less green house gases than gas cars, but still - similar problem.

My original point had nothing to do with consumption of resources, but thanks for the insight.

[canalon]

I truly suspect that considering the fact that water regulation in the atmosphere is better at getting rid of excess than CO2. And if I am not wrong clouds increase greenhouse effect, but also reduce the amount of solar heat, so I am not sure if water is as bad as CO2. Plus many places could do with a more humid atmosphere

I guess that what mith say would be a first thing, and my second problem is how you are producing the H2, because if you burn oild to do it, that is going to be pointless. Although I remember that H2 storage was suggested to even out the peak and holes of solar and wind electricity. Basically you would produce H2 when the wind or the light is here, and slowly "burn" it to produce electricity with a continuous output (so lots of wind, you store H2, less, you use the stored H2). That looked pretty neat to me. I can see a wind mill in my garden to produce the fuel for my car

[Darwin420]

Good point