Biosphere Contents

1. Organic Matter

Human activity has substantially reduced global primary productivity

Humans are estimated to have reduced global net primary productivity available to natural ecosystems by 23.8%, of which 53% relates to the direct harvest of material for uses such as food, fuel and shelter, 40% relates to land-use-induced changes in productivity, and 7% relates to human-induced fires (Haberl et al. 2007). This represents the largest diversion of the Earth's net primary productivity to a single species in the history of the planet and has clear implications for the prospects of future population growth. Although the main effect of this has become evident from the clearing of tropical rain forests over the last forty years, this process has been going on since the late Stone Age in the temperate forests.

Pictures of ecosystems affected by human activity

What effect has human activity had on global primary productivity?