Re: Hydrogen
Cement is carbon-positive in manufacture, but is carbon-negative in use - the very process of it curing is re-absorbing the carbon expelled from it. See various references to Biosphere 2 where the ecologists' CO2/O2 monitoring numbers made no sense as they weren't construction engineers and had no idea of the carbon properties of the concrete they'd built the thing with.
Biting the hand that feeds IT
