In the animal world, species move through demographic cycles which typically follow a pattern of “boom and bust.” Rampant reproduction encounters a threshold known as “carrying capacity” beyond which the environmental resources essential to that species deteriorate, leading to a sharp decline in its population. Whether the carrying capacity has been breached through overpopulation or overconsumption is a matter for nature to resolve.
Humans possess the unique power to influence their own carrying capacity on planet Earth. They know the factors that will dictate its level – the global population, the economic capacity of individuals to consume resources, the technologies available and lifestyle choices.
Exercising wisdom in mixing this cocktail is proving highly problematic, largely because our politicians have proved incapable of acting on the warnings of our earth scientists. The extreme inequality that pervades humanity may be to blame for this dysfunction of national and global governance. Very affluent individuals and corporations consume excessive resources and have sufficient power to hold governments to ransom in resisting change.
Such are these extremes that, even if the global population was stabilised tomorrow, the roll-call of environmental threats – climate change, loss of biodiversity, water scarcity – would remain. Studies published by the Stockholm Resilience Centre suggest that four out of nine environmental boundaries critical to a sustainable planet have already been crossed.
Projections of the world population show that its growth will be located almost entirely within low income countries where consumption is a small fraction of that in mature economies. Action to reduce consumption in these richer economies will accelerate prospects for sustainability far more than action to reduce the global population.
The immediate priority is to find a narrower and less damaging range of consumption in which the less fortunate can live in dignity but which in aggregate remains within our planetary boundaries.
The obstacle is our global addiction to a measure of economic success which rewards consumption of resources rather than the sustainability of their use. Economic “growth”, as currently quantified, is arguably far more damaging to the planet than population growth, yet is relentlessly pursued.
The Sustainable Development Goals approved in 2015 include Goal 12: “ensure sustainable consumption and production patterns.” However, the targets make no reference to the necessary reforms in measuring economic “growth”.
more Population briefings (updated August 2021)
World Population Projections
Opposition to Family Planning
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