Human Appropriation of Net Primary Production (HANPP) [BIP]
Human Appropriation of Net Primary Production (HANPP) [BIP]
Indicator description
The concept of human appropriation of net primary production (HANPP) has first been proposed in a seminal study by Vitousek and colleagues in 1986; his estimate that humans appropriate 19-40% (depending on different variants) of the products of photosynthesis has been prominently used to illustrate the biophysical size of the human economy vis-à-vis the productive capacity of the biosphere (Daly 1992). Since, the HANPP framework and methods to quantify HANPP have been greatly advanced and standardized (see Haberl et al. 2014 for a review) and applied to research on e.g. the human domination of ecosystems, biodiversity research, research on trade-offs in the land system or planetary boundary reserach.
HANPP is an indicator that assesses the extent to which human activities affect flows of trophic energy (biomass) in ecosystems, namely net primary production (NPP), which is a key process in the Earth system. HANPP, measured in units of carbon per year, is the sum of two subcategories: HANPPluc and HANPPharv. HANPPharv is the quantity of carbon in biomass extracted (harvested) by humans or consumed by their livestock per year, including crops, timber, harvested crop residues, forest slash, forages grazed by livestock, and also biomass lost to human-induced fires. HANPPluc denotes alterations in NPP resulting from human-induced land use change, such as the conversion of forest to cropland or infrastructure land. HANPP and its components can be expressed as annual flow of carbon or as percentage of the potential NPP (NPPpot), i.e., the NPP that would prevail in the absence of land use.
From a societal perspective HANPP measures the combined effect of land conversion and harvest on biomass flows in terrestrial ecosystems of a defined area of land; in other words, the combined effect of human-induced land-cover change and land use. From an ecological perspective, HANPP is a measure of the impact of land use on the availability of trophic energy (biomass) for heterotrophic food chains. In that perspective, HANPP measures the changes in the amount of NPP remaining each year in ecosystems resulting from land use. From both perspectives, HANPP is indicative of the intensity with which humans use the land, but the socioeconomic perspective is focused on the activities causing change, whereas the ecological perspective is focused on the impact on the system under consideration. (cf. Krausmann et al. 2009, Haberl et al. 2014).
Embodied HANPP (eHANPP) is a derived indicator which measures the HANPP embodied in a product. The eHANPP method allows researchers to account for the HANPP resulting from the production chain of a product, or of the entire consumption within a defined entity, such as a national economy. It can be used to analyze global teleconnections in the land system.