People are smarter than fish

During my holidays, and looking out over the horizon of the Atlantic Ocean (and perhaps after a few beers) I realised that people are smarter than fish.

Fish swim in the water (H2O) and get oxygen (O2) out of it to live.

On the other hand, we need to get hydrogen (H2) out of the water to save this planet.

It took a million years to make carbon (from plants, fish, …) down there in the earth. Can we burn all this carbon in a few hundred years and slowly destruct our world knowing the solution is so close to us ?

If fish can decompose water, why can’t we ?

* some chemical mistakes are made, probably too much OH in the beer.