In the editor's note:

Note that even under the very best of conditions photosynthesis is less than 2% efficient at turning sunshine into biomass. The average is much lower than this. Humans as a single species already use around 40% of the available energy from this process, known as the Earth's primary productivity. To think that we could mimic photosynthesis industrially, and improve its efficiency seems hugely arrogant. Four billion years of evolution have been working towards the same end.