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 of the extreme inequality in our current consumption.
According to the Global Footprint Network, if all countries adopted the American lifestyle, we would require five planets to supply the necessary resources. Yet the American lifestyle is an understandable aspiration of those many poorer countries which live within their ecological capacity.
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.
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 efficiency 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 March 2018)
World Population Projections
Opposition to Family Planning
Source material and useful links