Sub-zero water splitting marks a new dawn for solar hydrogen production
Just as burning fossil fuels cause dangerous reconfiguration of earth's atmosphere, I think that the idea of a hydrogen economy requires careful thought. Hydrogen shares with helium a unique property, that it is at escape velocity at the temperatures of the upper atmosphere. It seems unfathomable now, but if we converted all earths water into hydrogen and oxygen without containment, the planet would become a dead rust ball. It's not that these technologies should not be pursued, merely that adopting any technology on a planetary scale, should require some incredibly serious consideration.