"If the earth must lose that great portion of its pleasantness which it owes to things that the unlimited increase of wealth and population would extirpate from it, for the mere purpose of enabling it to support a larger, but not a better or a happier population, I sincerely hope, for the sake of posterity, that they will be content to be stationary, long before necessity compel them to it." –John Stuart Mill

I have followed the population debate with great interest, but in general it seems to ignore a larger issue. Would we want a greater population even if it were sustainable? Moreover, the debate obscures the fact that we must reduce population and economic growth simultaneously, as folks like Bill Rees, David Pimentel, and others have pointed out for a long time. Efforts to lay blame on one or the other for our current crises only divide us when we need to be united in calling for a lighter footprint on the earth. Charges of racism or xenophobia against those who do not wish to ignore the population dilemma drive us further from a united and comprehensive solution to the problems.

I come at the conversation as one who has focused almost exclusively (and wrongly, I believe) on the overconsumption side of the IPAT equation. I made the hit PBS special Affluenza and co-authored the international best seller by the same name. Both laid the blame for our inequality and environmental crisis on overconsumption. In our defense, that was more the case then (1997) than it is a quarter century later. At the time, we, and the activist group Adbusters, pointed out that the typical American consumed ten times as much as a resident of China, thirty times as much as someone from India.

But in the meantime, China and India, to differing degrees, have narrowed the gap. Their combined consumption is now immense, exceeding that of the US, and China's total carbon footprint is now higher than ours. At the time, Bill Rees and his "ecological footprint" analysis suggested that we would need five Earths were the rest of the world to catch up to US consumption levels. Surely, the numbers are far more dire now, as many lower-income countries have leapt into the consumer society in the past twenty-five years.

Moreover, we know that carrying capacity in many countries (like Canada or Russia) is far higher than in China, India, or Sub-Saharan Africa, for example. Unless we assume the populations of these places will suddenly move north (with no immigration restrictions), the implications for wildlife and biodiversity in them are grim indeed. We can feed Earth’s existing population, and perhaps even ten billion, but at what cost?

Already, humans and their domesticated animals account for about 95 percent of the world's mammalian mass, and we are continually depriving other species of habitat for our "productive" industrial agriculture and expanding population centers, or killing them with our poisons. There is no doubt that empowerment of women has reduced, and can reduce, the rate at which population grows but it has not stemmed the overall explosion of people, just as more environmentally friendly technologies have not “decoupled” economic growth from environmental impact.

Without question, offering Nature "half" as E. O. Wilson suggested, or even achieving the “30 by 30” goal (30 percent left wild by 2030) that the Biden administration wishes, is rendered nearly impossible by the inexorable increase and surging appetites of people.

Moreover, as Fred Hirsch wrote in his 1976 Social Limits to Growth, many goods that humans desire are not assembly-line products: they are "positional" goods that increasing population renders more scarce—access to good land, to nature, to beaches, to green space, to silence, to beauty, for example. These quality-of-life concerns are not trivial. Increasing research shows that living in more natural settings with access to parks, aesthetically pleasing environments, and green space not only improves life satisfaction but also aids both physical and mental health, reduces crime, decreases polarization, and increases people's desire to stay where they are instead of continually migrating.

"Everyone needs beauty as well as bread," declared John Muir 150 years ago. "Give us bread but give us roses," demanded the immigrant millworkers of the 1912 Lawrence Textile Strike. "Beauty will save the world," wrote Dostoevsky.

Today, the beauty of the world, which is hardly only "in the eye of the beholder," but coveted by all races and classes, is being overwhelmed by the pressures of population. Our national parks are bursting at the seams, and quiet contemplation of nature's beauty, an important factor in mental health, is squeezed out, or poorly substituted for by videos on our phones. Moreover, sustainable methods of agroecology, needed to protect other species, cannot compete in pure production of calories with industrial agriculture. The “Green Revolution” unquestionably prevented famines and allowed greater population growth, but again at what cost to the Earth and the other species we share it with.

So let us not waste time fighting between consumption and population. Fifty years ago, the book Limits to Growth made clear that both are leading us over the edge to catastrophe. It is time now to advocate degrowth of both population and consumption, while making clear that a simpler, more sustainable life can also be a healthier, happier one (and the evidence for that is powerful).