Overshoot And The Population Conundrum

The human enterprise is in overshoot, depleting essential ecosystems faster than they can regenerate and polluting the ecosphere beyond nature’s assimilative capacity. Overshoot is a meta-problem that is the cause of most symptoms of eco-crisis, including climate change, landscape degradation and biodiversity loss. The proximate driver of overshoot is excessive energy and material ‘throughput’ to serve the global economy. Both rising incomes (consumption) and population growth contribute to the growing human eco-footprint, but increasing throughput due to population growth is the larger factor at the margin.... Mainstream approaches to alleviating various symptoms of overshoot merely reinforce the status quo. This is counter-productive, as overshoot is ultimately a terminal condition. The continuity of civilisation will require a cooperative, planned contraction of both the material economy and human populations...

Introduction: Contrasting approaches to population

My thesis in this paper is that modern techno-industrial (MTI) society is in a state of dangerous ecological overshoot—i.e., that there are too many people consuming and polluting too much on a finite planet.... Planet Earth is also an island in space with a limited productive land area, but it is threatened by rampant ecological degradation (including accelerating climate change), continuous conflict over habitable territory, evidence of incipient energy and food shortages... Nonetheless, there are no national or global plans for population management.... In short, the ‘population question’ is still largely a taboo subject... Earth’s population of 7.9 billion people is still growing by more than 1% (80 million people) per year...

The growing list of so-called ‘environmental problems’ is empirical evidence that we humans are literally depleting and contaminating the biophysical basis of our own existence. We are the problem. The destruction of essential natural capital erodes the functional integrity of the ecosphere and undermines life-support functions vital to human survival. The long-term costs are incalculable. Ecological economist Herman Daly has suggested that overshoot coincides with uneconomic growth; i.e., with growth that impoverishes rather than enriches.... The acceleration of climate change is merely the most popularised single symptom. (Humans tend to think in simplistic, reductionist terms).

Most important, while over-consumption and population growth have long been recognised as co-drivers of overshoot (Ehrlich and Ehrlich, 2014; Ehrlich and Holdren, 1971), population growth is currently the major contributor to total consumption growth and associated negative ecological impacts in all four income categories....

... 'peak population' and subsequent population decline in high-income countries should be cause for celebration. Population growth in the richest nations generates almost an order of magnitude greater demand for biocapacity than an equivalent numerical gain in low-income countries.

In the real world, of course, the population is still growing and there is zero international interest in sizing the global economy to fit within carrying capacity.... Perhaps this is to be expected. Despite our much-vaunted high intelligence, H. sapiens is not primarily a rational species. We tend to be foolishly short-sighted and are prone to selfishness... emotions, instinct, cognitive dysfunction and acquired habits—often operating beneath consciousness—dominate personal and political behaviour.... For example, humans share with all other organisms the inherent propensity to expand to fill all accessible habitats and to use up available resources, but with the major difference being that our technological prowess is constantly upgrading the resources that are 'accessible' and 'available'.

The human population, at present average levels of consumption, exceeds the carrying capacity of the ecosphere and is well into overshoot, as revealed by eco-footprint analysis and myriad other data (solid red line). However, consumption continues to grow, depleting resource stocks and undermining remaining biocapacity. A truly rational species would have maintained its population below carrying capacity (solid green line), consistent with one-planet living... This option is no longer available. As we near peak population, the global community must choose between cooperation to manage a controlled population contraction within the remaining regenerative capacity of the ecosphere (dashed red line) or enduring a violently chaotic systems collapse in which billions will suffer.

Humanity's techno-hubris is exceeded only by collective denial and ignorance of systems behaviour.

The as-yet-unacceptable alternative—acknowledging overshoot and recognising that a major reduction of both population and economic throughput (consumption and pollution) is the only way to eliminate it—is barely beginning to take form... The overall goal must be to establish and maintain the necessary conditions for a smaller human family (one to two billion people) to enjoy both economic and ecological security through 'one-planet living'.