Direct use of photosynthate by humans
(reasonably reliable estimates)


Photosynthetic stocks and productivity
Total terrestrial biomass

1244 Pg

Total terrestrial annual NPP

132 Pg

Total aquatic annual NPP

92 Pg



By analysis of food consumption:
Human population

5 Billion

Caloric intake

2500 kcal/per/d

Total OM used:

0.91 Pg



Calculated from -
food prduction, animal production, wood product use, fisheries output, etc... i.e. all inputs and all outputs, whether or not they get eaten:

Total OM used:

7.2 Pg

Percent NPP:

3.2%

from Vitousek et al. 1986. Human appropriation of the products of photosynthesis. BioScience 36: 368-373