Fig. 1: Schematic of potential pathways to synthesize food without agriculture.
From: Food without agriculture
Proteins, fats and carbohydrates can be synthesized from a range of carbon feedstocks via multiple chemical and biological pathways (arrows). The weight and colour of the arrows indicate the scale at which the different processes have been demonstrated and the energy required per mass unit output, respectively (see Supplementary Fig. 1 and Supplementary Table 1 for references). Dashed lines indicate where energy requirements remain highly uncertain. Circular labels on each arrow further indicate whether the process is typically continuous (C) or batched (B). NH3 is ammonia, H2 is hydrogen gas, MeOH is methanol and AcO- is acetate. In the context of this study, we exclude agriculturally produced carbon feedstocks.
