The other major failure of the Tilters is their assessment of overpopulation. On the positive side, most of the Tilters are at least willing to engage with the issue and to tell some difficult truths. Population is not an easy topic for people who care about human rights. Historically, some very nasty elements have used population as an excuse for “population control” policies constructed around a simmering racist metanarrative: the problem is really that brown people are too stupid and/or too sexual to control themselves. Those of us who come to the population discussion from the perspective of resource depletion, human rights, or feminism have to distinguish ourselves from the racist history entwined in the issue. When we say “overpopulation” we need to define what we mean and why it matters.

What I personally mean is that the earth is a bound sphere. The planet is finite. There are absolute limits to the numbers of individuals that any species can attain. That is what carrying capacity means: how many members of a species the environment can support indefinitely. Too many members and that species is drawing down resources, degrading the landbase for itself and for other species, and will most likely end in extinction. That is physical reality. For most of human history, we were very aware of the limits of our surrounding community. Hunter-gatherers know the ratio of productive adults to dependents that must be maintained to stave off hunger and ultimately degradation of the biotic community. Everything from abstinence to herbal abortifacients are mobilized, with infanticide as the fall-back plan. An Inuit woman whose husband died was expected to kill any children she had under the age of three.31 The Arctic is a harsh climate and too many dependents means the whole community will suffer. That’s actually true for all human societies, but in a more demanding environment the ill effects (hunger) of a skewed dependent-to-producer ratio will be felt immediately.

What broke the cultural knowledge of those relationships was agriculture. By drawing down entire ecosystems, humans were able to dramatically increase their numbers. Remember that agriculture is the replacement of biotic communities with monocrops for humans. Agriculture has let vast amounts of resources accumulate into more and more humans—sunlight, rain, rivers, soil. With the soil used up, the monocrops are now fertilized by fossil fuels. If you’re eating grain, you’re eating oil on a stalk. With the rivers drained and the water tables falling, the crops are now irrigated by fossil acquifers. The water is so inaccessible that oil drilling equipment is necessary to reach it. Huge swaths of our planet, once lush with forest, are nothing but scrub and salt. That profound drawdown is what is supporting our current numbers.

And here’s a problem in the discourse about the dilemma. Many sustainability writers take the current level of resource extraction as an unquestioned baseline. They assume the amount of grain now being produced can simply go on indefinitely. It can’t. It’s based on drawdown and long-term destruction of entire continents, a destruction that is about to hit bottom.

I appreciate how Brown understands that historically, soil destruction and salinization have brought down previous civilizations, and the grim possibility that this future awaits us. The United Nation projects a world population of 9.2 billion by 2050. Brown addresses this head on:

I do not think world population will ever reach 9.2 billion … The land and resource base is deteriorating and hunger is spreading. Simply put, many support systems … are already in decline, and some are collapsing. The question is not whether population growth will come to a halt before reaching 9.2 billion but whether it will do so because the world shifts quickly to smaller families or because it fails to do so—and population growth is checked by rising mortality.32

He states with the clarity of emergency, “If we cannot … stabilize population and climate, there is not an ecosystem on Earth that we can save.”33

Brown is equally clear that raising the status of women and eliminating poverty are key to lowering the birthrate. He writes, “If the goal is to eradicate hunger and illiteracy, we have little choice” but to lower our numbers. He includes debt relief, universal health care, primary education especially for girls, and access to family planning as basic steps toward reaching that goal. All that is worth fighting for. All of it would help move us toward a truly sustainable future. None of it is enough.

Capitalism, especially the corporate version, has got to be dismantled, to be replaced by democratically controlled economies. If that includes a market economy, the markets must be nestled inside subsistence economies. Tilters like Brown can identify poverty as a factor in population overshoot, but they don’t identify capitalism or civilization as the leading cause of poverty. Brown’s solution is that, along with their sunshine, “low-income countries” are supposed to sell off whatever is left of their so-called resources. Brown urges funding to allow the third world to “develop their unrealized potential for expanding food production, enabling them to export more grain.”34 Brown is worried that peak oil may interrupt “international flows of raw materials.” Such flows of raw materials are the model that has condemned the majority of the world to poverty and the earth to destruction. Those “raw materials” need to remain what they are: living forests, grasslands, rivers—soil-building communities that are the matrix of life. And the human members of those communities need relief from the relentless assaults of the globally powerful.

But what the planet needs most is relief from the relentless assault of agriculture. Like almost everyone alive today, the Tilters don’t realize that agriculture is biotic cleansing, drawing down species, ecosystems, and soil to temporarily increase the planet’s carrying capacity for humans. This is also the blind spot endemic to claims that shifting grain from animals to humans would solve world hunger: that grain is only temporary.

Brown proposes increasing food supplies by raising land productivity through fertilizers, irrigation, and higher-yield varieties. The disconnect in this thinking makes my head hurt. He knows that humans are destroying the climate with fossil fuels, yet his solutions depend on more of the same. The fertilizers are all derived from gas and oil; and their day is done. Irrigation results in soil death by salinization and has brought down a great number of preindustrial civilizations. It also results in river death by dewatering: a fish out of water is a dead fish. Eighty percent of China’s rivers, for instance, now support no life. Irrigation also brings devastation to the surrounding wetlands, which should be the most species-dense habitats on the planet and are now historic oddities. Water tables have dropped so far that half of India’s hand wells are dry, forcing people into desperate urban slums.35 Agriculture provides its final insult to the land when water tables drop below the reach of tree roots. Trees are the backbone of their biotic communities: without them, the world is emptied to a monoculture of dust. Oil drilling equipment, which requires the cheap power provided by fossil fuels, is then necessary to get the water.

Brown also suggests no-till agriculture. Somewhere in all of this he recognizes that plowing is destructive. Some forms of no-till agriculture require specialized equipment that can drill through plant residues, equipment that is both industrial and costly. Other no-till methods also use herbicides instead of mechanical means to kill the invading plants, plants that are nature’s desperate attempt to repair the world. Setting aside that such schemes will keep poor people dependent on industrial infrastructure, a cash economy, and the hierarchies behind both: do I really have to explain that coating the world in poison is a bad idea? There is no future for humans, for soil, for the winged and gilled in these proposals, or no future worth enduring. If we are going to face the truth about population overshoot, we need to actually face it.

No solutions that rely on agriculture will be real solutions. The soil will continue to collapse into sterile dust. Irrigation, the final tears of rivers, the last sigh of exhausted aquifers, will leave the land strangled with salt. The animals, from the awesome grace of the megafauna down to the tiny miracle of copepods—almost too small to see but aggregating into the largest animal biomass on the planet—have nowhere to go except the abyss of extinction, and not two by two but 200 at a time. This is what agriculture is: a funneling of biomes, once verdant with life and the resilient promise of more, into a monocrop of humans. The process is now nearly complete, its swan song a catastrophic failure of this once-living planet.

Despite the declarations of an inexplicably popular book, the world was not created for us. No marginally rational person would believe such insanity. As apex predators, we are utterly dependent on the work of millions of other creatures who took a cold rock and turned it into a home. “Go forth and multiply” is the clarion call of entitlement. We don’t have a right to more than our share. We will not save this planet as long as agriculture—its religion, its psychology, its entitlement—continues.

Eight billion people are dreaming, except that such a dream would be more like a nightmare. So how many people could this planet support sustainably? In 1800, the beginning of the fossil fuel age, there were one billion people. Many resource depletion writers choose one billion as a benchmark. Such people have faced some hard truths, but they have not gone all the way to the bottom. In 1800, vast swaths of the planet had already been destroyed by agriculture and overshot by humans. A truly sustainable number would be somewhere between 300 and 600 million. It may sound impossible; it may be impossible, given the time we have left. On the positive side, the same social and political processes need to be set in motion whether the goal is eight billion, one billion, or 300 million. If we can do it at all, we might as well do it right.

One positive fact about being alive is that we’re all going to die. If we can start reproducing at below replacement numbers, the problem would take care of itself. And it won’t even take that long. At just over two children per woman, population continues to rise because of the number of existing children who have yet to enter their reproductive years. But at one child per woman, the global population would decline to about a billion around 2110. That billion could be reached in fifty years if adult mortality triples—and the human race has faced far worse mortality rates over its history. Some places are already undergoing increased mortality, and though personal suffering is obviously involved, the societies as a whole are not collapsing into lawless disorder as the population contracts (see our discussion of Russia, below).

Currently there are seventy-five countries with populations reproducing at replacement levels (2.1 children per woman). Thirty-three countries, in fact, have negative population growth. In some cases, that’s due to high standards of living and civil rights for women, both of which have a huge impact on population levels. In other countries, though, the reasons are grim: disease, especially AIDS, the social strains of war and poverty, and ecological collapse. In very stark relief, these facts show us the possible futures—we voluntarily and peacefully address the social forces behind population overshoot, or nature will do it for us.

Projections, Population of the World

- - - - - UN scenario: fertility declining from 2.6 children per woman in 2004 to slightly over 2 children per woman in 2050. Source: Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat (2005). ———Scenario assuming that all fertile women are henceforth limited to 1 child. Source: Dr. Sergei Scherbov, research group leader, Vienna Institute of Demography, Austrian Academy of Sciences. CHART BY JONATHAN BENNETT

The questions we must face are: Will we—planetwide, species “we”—recognize the problem? Will governments and other major institutions set the necessary policies in motion? Or will the Catholic Church continue to condemn condoms? And will our planet be able to withstand the power shifts and strains until our numbers begin to decrease?