The panorama is so vast that it gave rise to three scientific magazines devoted to the Anthropocene (see the large research programmes on Global Change coordinated within the Future Earth Programme, www.futureearth.org.)
Over three quarters of the earth’s biosphere have already been dramatically transformed in anthropogenic biomes. This – as Erle C. Ellis, an ecologist at the University of Maryland states in his essay “Ecology in an Anthropogenic Biosphere”, published in the scientific magazine Ecological Monographs – has occurred because of many factors including, for example, population growth and profound changes in the use of soil and geomorphology of the original environment.
Data on energy and material flows transferred from natural systems to social ones, in other words to industrial metabolisms of our societies, are all too well known (see www.materialflows.net) and have a huge impact on the preservation of natural capital of the Earth system. By natural capital – as pointed out by the most recent scientific literature – we mean living and non living components of ecosystems that contribute to generate goods and services that humankind can utilize.
In such research and application fields, great attention is being given to a very important indicator, useful to understand human-induced changes to the evolution dynamics of natural systems and material and energy flows circulating within them. We are talking about Human Appropriation of Net Primary Productivity (HANPP), which was first investigated by Stanford University’s great ecologists such as Peter Vitousek, Paul Ehrlich and Pamela Matson, with a work published in 1986 on Bioscience, “Human appropriation of the products of the photosynthesis”.
Net Primary Production (NPP) measures the net quantity of solar energy being transformed by plants through photosynthesis into organic matter and thus made available to other levels of the food chains in the whole biosphere. A significant part of NPP is then used by our species, through soil conversion and biomass production (HANPP). Therefore, this is a very significant indicator of the scale of human activities and it is strictly linked to the socioeconomic metabolism measured by other indicators such as material flows.
The scholar Steven Running at the University of Montana, in his work appeared on Science, suggested that HANPP be considered as a new planetary boundary in the international debate and political actions for sustainability to be added to the planetary boundaries already indicated by illustrious scientists in the two publications on Nature in 2009 and on ScienceExpress in 2015, and already dealt with in Renewable Matter issue 2 in the interview with Johan Rockström, director of the Stockholm Resilience Centre.
The latest data reveal that human appropriation of NPP went from 13% of 1910 to 23% of 2005. By 2050 it could soar to between 29 and 44%.
Besides stealing vital organic matter from the rest of life on Earth, human appropriation of net primary productivity alters the composition of the atmosphere, the wealth of biodiversity, the energy flows through food chains as well as the supplying of important services to ecosystems. This is the reason why it represents a valuable indicator to assess the preservation of natural capital.
Running S.W., “A Measurable Planetary Boundary for the Biosphere”, Science, v. 337, 2012; doi: 10.1126/science.1227620
Krausmann F. et al., “Global human appropriation of net primary production doubled in the 20th century”, Proceedings of the National Academy of Sciences, v. 110, n. 25, 2013; doi: 10.1073/pnas.1211349110
Haberl H. et al., “Human appropriation of net primary production: patterns, trends and planetary boundaries”, Annual Review of Environment and Resources, v. 39, 2014; doi: 10.1146/annurev-environ-121912-094620