Graph of the Day: Global biocapacity per capita, 1961-2012

By Jim Galasyn
27 March 2016 (Desdemona Despair) – The Global Footprint Network has published their latest ecological footprint analysis for the world and for individual nations. Not surprisingly, the ecological footprint of human civilization continues to rise at a steady rate of about 235 million global hectares per year. Over the period from 1961 to 2012, humanity’s ecological footprint has nearly tripled. During this time, Earth’s biocapacity declined at a steady rate of about 55 million global hectares per year. Biocapacity is defined as the amount of biologically productive land and sea area available to provide the resources that a population consumes and to absorb its wastes, given current technology and management practices (Methodology and Sources). From the biocapacity data and the known human population, it’s easy to compute biocapacity per capita, which looks like this: Biocapacity per capita is declining at an exponential rate. Extrapolating the curve fit shows that it will fall to half of its 1961 value by around the year 2020. By the year 2100, biocapacity per capita will fall to about one-sixth of its 1961 value, which means that each human will be supported by about 17 percent of the ecosystem services that each human was supported by in 1961. This curve is likely to be related to other measures of habitability discussed in a recent Desdemona post. Clearly, the biocapacity-per-capita metric is closely related to arable land per capita:

Currently, the world has 0.2 hectares (0.49 acres) of arable land per person, down from 0.4 in 1962. Extrapolating the exponential curve, we’ll be down to 0.1 by around 2050, and 0.05 by 2100. So, every 50 years, arable land per capita declines by half. By the year 2100, each person will be supported by just 0.05 hectares (0.12 acres) of agricultural land. (Is the epoch of habitability on Earth drawing to a close?)

Also, it’s likely that biocapacity per capita is related to Schramski’s Ω metric, phytomass per capita (Human domination of the biosphere: Rapid discharge of the earth-space battery foretells the future of humankind). You can get the data and related graphs here: Global Footprint Network for World 2016.