How many humans can the earth system sustain under different scenarios of “development status” that exist in current societies?

There is a need to link current limits in natural systems (e.g. freshwater resources, agricultural productivity, natural versus altered habitats, ability of ecosystems to tolerate pollutants, etc) to the size of the human population, recognising that the earth system does not have infinite resources. This can help contextualise current conflicts, anticipate future ones and indicate limits to growth that should inform all individuals. This is a politically-sensitive topic that needs to be addressed from local to global scales in order to understand the consequences of global change in the future.

One comment

1. Erik Buitenhuis says:

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   I agree that the I=PAT formulation (impact=population*affluence*technology, in which for technology read for instance the carbon intensity of the economy) is still a useful way of looking at global environmental problems and that the discussion is dominated by technology, only because it’s more challenging to discuss population decrease and less resource intensive lifestyles. I note, however, that studies in the USA have shown that reported happiness has been decreasing for decades despite increased affluence, and both the living planet index and my personal experience agree that it is indeed possible to lead a sustainable high quality lifestyle.