Random Science Fact of the Day:
Incidentally, water is synthesized via any organic combustion reaction (in which a hydrocarbon such as methanol, or rocket fuel, is ignited and allowed to react with excess oxygen gas). The other product of such a process is carbon dioxide.
This is why water vapor is the most abundant greenhouse gas by at least a factor of four and why carbon dioxide is the second-most abundant. Yes, water vapor is the most abundant greenhouse gas.