The terrestrial biosphere’s preindustrial Holocene Net Primary Production (NPP_Holocene) average has been determined at 55.9 Gton C/year. For a given year, the global Net Primary Production remaining after appropriation (NPP_eco) was estimated at 51 Gton C/year.

a.  [10 pts] Explain what is the Human Appropriation of Net Primary Production (HANPP) and how it influences the biosphere integrity.

b.  [10 pts] Calculate the control variable value (% HANPP) for the functional component of the biosphere integrity boundary and determine if the planetary boundary is transgressed.