Hydrogen combustion engines? increase?

Question

Water vapour is the #1 greenhouse gas and as the world warms so does the amount of water vapour in the atmosphere increase.

If all our motor vehicles were hydrogen burning then the greenhouse effect would be much worse than it is today because burning hydrogen produces water vapour.

It is true that the atmosphere can only hold so much water vapour before it precipitates - rains. But most of the time our atmosphere has nowhere near its maximum quantity so there is a lot of room for more water vapour in our atmosphere and, therefor, water vapour can violently increase global warming.

The amount of water vapour in the air would, in and of itself, increase the amount of viscious storms. The warmer the climate gets the more water vapour can be held and the cycle would seem to continue.

Right?

Answer 1

Not even close.   Here's what you're missing:

Gallon of gas releases about 20lbs of CO2 and also about 9lbs of water.   Both greenhousegas constituents were dredged up from stored reserves, sequestered.   Adding a new source and increasing the quantity of both GHGs in the atmosphere.  

2lbs of hydrogen releases 18lbs of water.   Which came from the surface originally.   No net increase of GHG in the atmosphere.

Answer 2

I think you should go back to the drawing board and study the subject a little more

Answer 3

Sounds somewhat reasonable, but what about clouds?   All this excess vapor will condense into clouds, which will reflect sunlight better than the ground, thus cooling the earth too.    Your question is one of the unknowns that people far smarter and with more information than either of us are working on trying to figure out.

Answer 4

The amount of water vapour in the air is a function of the enthalpy. This again is given by the level of energy... and the main source of energy at the surface of this earth is the sun.

To have the vapor contained in the air to condensate (rain) you need to have the volume of vapor saturated air to intermix with a mass of cold (and possibly dryer) air. This might decrease under our temperate climates as the ice cover of the arctic (which reflected the light, thus keeping the temperatures low) melts. As a result, less flow of much colder air would be available to create the condensation.

It is all physics and let me find the graph:

http://rtsoftwaredevelopment.de/html/tab...

(sorry could not find a good one in english)

Answer 5

Even though the humidity of the air in not 100% all over the world all the time, clouds still form and rain still falls, because local instabilities change the capacity of the air to hold water. The water cycles works VERY fast compared to the carbon cycle. Water vapor added top the air gets removed again in a few days. Carbon dioxide takes hundreds of thousands of years to be removed. And it isn't trees that do it. It is mostly life in the sea that takes up the carbon, dies, falls to the bottom, and gets buried by sediments and eventually subducted deep into the interior of the planet by plate tectonics. If humidity goes up, the amount of rain goes up right away. The amount of CO2 removed will not go up nearly so quickly because those processes are much slower.

Answer 6

Depends where the energy to make the Hydrogen comes from.  If you are removing energy from the biosphere (the "skin of the apple" that we live in) to make H2 and then returning it during combustion as warm water vapour the net effect is zero plus you are not creating "long term" green house gasses (it takes nature up to 200 years to process CO2 out of the atmosphere, the water cycle happens much faster) so there is a net benefit.