Abstract

Two insights are crucial to respond to the title question. First, understanding the challenge we face in time and extent, and secondly, understanding the factors causing the environmental crises (climate, biodiversity, pollution). Environmental crises are caused by the transgression of now six out of nine planetary boundaries, and by reaching or crossing several tipping points of the climate and biodiversity system. The time we have to avoid irreversible degradation processes and tipping cascades humans are not able to stop once they have started, we have about a decade A convenient tool to visualize the relationship between environmental impact and the forces driving them, is the so-called IPAT Formula, which is one (of many possible) ways to disaggregate the pressures: Impact = Population * Affluence * Technology or I = P * A * T (Ehrlich and Ehrlich 1991). As population refers to the absolute size (i.e., not the growth rate), affluence is defined as consumption per capita, and technology as impact per consumption, it is a tautology and cannot be wrong if the definitions are respected. Relying on Technology, and assuming that technological improvements allow combining higher affluence and reduced impacts, does not and will not work – “Green Growth” is an illusion.

As technology T can be ruled out as a decisive factor, this leaves us with Population P and Affluence A, i.e. the consumption per capita. Both factors are influential, but their relative weight has changed. In the second half of the 20th century population growth was the most important factor and hence the key indirect driver of environmental degradation, but since the turn of the century affluence has become dominating. In this respect, we could speak of a first and a second phase of the Anthropocene, and if the name is intended to spotlight the main drivers, call them Populocene and Consumocene. Current projections of population development and economic growth hint at an emerging even stronger dominance of consumption: while the world population is expected to grow by about a quarter by 2050, world GDP and hence consumption are projected to almost quadruple by 2050. Given this, the policy priority for steering the world back below the planetary boundaries are obvious: consumption increase must be halted, and average consumption levels reduced. However, the current distribution of consumption is highly uneven, and has become more so during the pandemic. Hence reducing the average while overcoming poverty – which also increased significantly during the COVID era – will require a significant redistribution of wealth between the center and the periphery within and between countries (unlike 20 years ago, the inequality within nations is now higher than the one between nations).

Adding the urgency argument to the scale argument, it is clear that the size of the population cannot be reduced significantly over the next decade, except through a nuclear war or deadly pandemic. Both are not sustainable solutions. Consumption and affluence, including redistribution, can be done in the short term – they do not require moonshot technologies nor mass killing, but rather the political will and the public insight in the necessities.