Holy Biomass Grail
Converting to a “hydrogen economy” given current mechanical efficiences will mean increasing the already unsustainable human agricultural footprint by around 50%.
The fossil fuels burned in 1997 were created from organic matter containing 44 ? 1018 g C, which is >400 times the net primary productivity (NPP) of the planet?s current biota. As stores of ancient solar energy decline, humans are likely to use an increasing share of modern solar resources. I conservatively estimate that replacing the energy humans derive from fossil fuels with energy from modern biomass would require 22% of terrestrial NPP, increasing the human appropriation of this resource by ~50%.