If CO2 cars are replaced with hydrogen cars, will it rain more?

Question

My understanding is that hydrogen powered cars do not emit CO2 but instead emit only water vapour. If millions of cars on the roads today are replaced with cars that emit only water vapour does that mean that the extra water vapour in the atmophere will produce more rain? or will we have a more humid climate? What would be the envirnmental implications of hydrogen cars?

Answer 1

I live in the UK

It rains constantly I don't think I would notice the difference

Answer 2

It won't really change anything. In addition to CO2, cars already emit a lot of water vapor and switching to hydrogen won't significantly increase the amount.

Answer 3

I suppose so, but not much more. Like 0.001% more. Because the amount of water vapor naturally in the air is FAR more than the amount of CO2 naturally in the air. The only reason our extremely small CO2 emissions are significant is that there is an extremely small amount of CO2 naturally in the air. That and the fact that natural mechanisms to remove CO2 are not nearly as quick and responsive as rain is at removing water vapor.

Answer 4

No.  The hydrogen will be taken from water.  Burning it will simply put that water back.

So it won't rain more.  But it may rain in slightly different places.  Not noticeably.   Global warming is also causing that to happen, and it's a lot more powerful force.

Answer 5

Can one imagine millions of fuel cell cars on the road putting out nothing but water as emissions? That will make one very slick road in the winter with all that ice all over the road from the emissions.

Answer 6

Absolutely not.  In fact, I am afraid it might even rain less.  

The hydrogen in hydrogen-powered devices comes from water that has been broken (which by the way takes a lot of energy).

Right now the biggest barrier to practical hydrogen applications is a way to store and transport the hydrogen.  It leaks out of every container or pipe they have tried to make.  

Being a very light gas, once it is gone, it is gone.  It floats away, perhaps even out of our atmosphere altogether.  To me this sounds like a very dangerous idea.  We destroy a quantity of water by breaking it down into oxygen and hydrogen, and then loose part of it so it can never be reconstitued again.  

I do not believe this is a wise path to follow.  Nowadays we have oil spills.  What if we had a "hydrogen spill"?  Have we forgotten that all life on earth is dependent on water?

Answer 7

It might have local impact

eg places with fragile dry ecosystems like Nevada, (imagine all the Las Vegas limos) or on poor housing on the side of arterial roads that are already suseptible to damp

Infernal combustion & jet engines also emit significant amounts of water vapour already, mixed with particulates and nitroeus oxides these form a nasty cocktail.

but hydrogen is a very inefficient form of energy storage & transport. it would be better to use battery vehicles anyway