I know this is a financial forum, but look: - If you burn hydrogen, no greenhouse gases are produced, aside from a small amount of water vapour. - Fuel cells DON'T burn the hydrogen, they use it as part of a chemical reaction to generate electricity. - There's no way we're emptying the oceans. There's more ocean than land, it's very deep, and the level is also rising.
I'm still not an expert, so counter away, but using excess power to generate something useful from seawater sounds good.
