Overpopulation

"Population, when unchecked, increases in a geometrical ratio, Subsistence, increases only in an arithmetical ratio."

"The power of population is so superior to the power in the earth to produce subsistence for man, that premature death must in some shape or other visit the human race."

"What has caused the recent super-exponential rise in world population? Before the industrial revolution both fertility and mortality were comparatively high and irregular. The birth rate generally exceeded the death rate only slightly, and population grew exponentially, but at a very slow and uneven rate. In 1650 the average lifetime of most populations in the world was only about 30 years. Since then, [hu]mankind has developed many practices that have had profound effects on the population growth system, especially on mortality rates. With the spread of modern medicine, public health techniques, and new methods of growing and distributing foods, death rates have fallen around the world. […] On a world average the gain around the positive feedback loop (fertility) has decreased only slightly while the gain around the negative feedback loop (mortality) is decreasing. The result is an increasing dominance of the positive feedback loop and the sharp exponential rise in population […]."

"H. sapiens took around 250,000 years to reach a global population of 1 billion in 1820, and just over 200 years to go from 1 billion to 8 billion. This was largely made possible by our species’ access to cheap, easy, exosomatic energy, mainly fossil fuels. Fossil fuels enabled us to reduce negative feedback (e.g. food shortages) and thus delay and evade the consequences of surpassing natural limits. In that same 200 year period, fossil energy (FF) use increased 1300-fold, fueling a 100-fold increase in real gross world product, i.e. consumption, and the human enterprise is still expanding exponentially."

"We’ve just welcomed the 8 billionth member of the human race on this planet. That’s a wonderful birth of a baby, of course. But we need to understand that the more people there are, the more we put the Earth under heavy pressure. As far as biodiversity is concerned, we are at war with nature. We need to make peace with nature. Because nature is what sustains everything on Earth … the science is unequivocal."

"The Earth's population is plagued by famines, energy shortages, epidemics, environmental pollution, degeneration, terrorism, dictatorship, anarchism, slavery, excessive increase of waste materials, racial hatred, food shortages, destruction of rain forests, the "greenhouse effect", pollution of lakes, streams and oceans, hatred towards asylum-seekers; radioactive emissions, chemical pollution of water, air, plants, food, human beings and animals. Crime, murder, mass murders, manslaughter; alcoholism, hatred of strangers, oppression, hatred of one's fellowman, extremism, sectarianism, drug addiction, overpopulation, annihilation of animal species, war, violence, torture and capital punishment, general mismanagement, water contamination, eradication of plant species; hatred, vice, jealousy, lovelessness, lack of logic, false humanitarianism, lack of housing, increased traffic, destruction of arable land, unemployment, the collapse of health care, the collapse of care for the elderly, destruction of nature, the collapse of solid waste removal, and the lack of living space, among others. In spite of the many efforts, mankind's problems are not decreasing but, instead, continue to rise steadily in direct proportion to population increases."

"… technology use harnesses far more energy and materials than we could ever manage without it, and while doing so may make our lives much easier and more comfortable, it comes at the cost of increasing ecological overshoot. As we increase overshoot, we concomitantly increase all the symptom predicaments that overshoot causes. Technology use also has another nasty side effect. It reduces and/or eliminates negative feedbacks which once kept our numbers in check. Many diseases we once suffered from like smallpox, measles, whooping cough, tetanus, etc. have been temporarily eliminated by the technological development of vaccines. Our medical industry has also wiped out many other diseases through proper sanitation, use of antiseptics, anesthetics (allowing surgeries to correct most internal ailments), antibiotics, antifungals, and antivirals to kill or prevent many diseases, and many other innovations that allow us to live better, more comfortable lives. The development of indoor plumbing, electrical systems, heating and air conditioning systems, insulation, refrigerators and freezers, and cooking devices all allow us to accomplish daily tasks either much easier or provide more comfort to us by regulating temperature and humidity levels in our living spaces. Therefore, technology use reduces or removes negative feedback thereby promoting population growth which also promotes technology growth. However, in terms of reducing overshoot (and symptom predicaments such as climate change, energy and resource decline, pollution loading, and biodiversity decline), technology use is maladaptive. This will become painfully clear as time moves forward when more or different technology does not actually solve overshoot. Population decline is what will actually work to reduce overshoot, caused by the failure of our agricultural systems, increased disease caused by antimicrobial resistance and new viruses emerging, and increased failures of infrastructural systems caused by extreme weather events. Reduced technology use will be facilitated by this mechanism, and ALL species wind up experiencing die-off whether they use technology or not."

"Most non-domesticated life on earth is in decline and about 200 species a day are going extinct due to a wide range of environmental problems. Many humans are at risk of being harmed or killed by related problems this century. All of the many problems are caused by the same thing: humans have used non-renewable energy to explode their population from 1 billion to 7 billion in 100 years, and now consume so large a share of the earth’s resources that almost all non-domesticated species are in decline."

"We’re in serious trouble. Many red lights are flashing on the dashboard. Most people are now aware that something is seriously wrong, and each has their favorite lens through which to view the problems… The common denominator to all of these problems is overshoot. Very few people are able to see through the lens of overshoot because overshoot is a very unpleasant topic with no painless solutions and no way to avoid its consequences, and because humans evolved to deny unpleasant realities like overshoot."

"Human numbers are rising at roughly 1.2% a year, while numbers are rising at around 2.4% a year. By 2050 the world’s living systems will have to support about 120m tonnes of extra humans and 400m tonnes of extra farm animals."

"Baconian science is at the root of the apocalypse. We have been blessed by advances in medicine, agriculture and engineering. Science has done exactly what we asked of it and now we are set for annihilation. If European science had petered out after the discoveries of the seventeenth century, we would be less numerous and [the] Earth would not be warming."

"This moment is special because we have dramatically built up our population, technology, science, medicine, and democratic institutions as a direct result of vast amounts of surplus energy stemming from a one-time resource. The fossil fuel experience has made us dangerously confident about our cleverness and dominance over nature. What makes this century special, then, is that we will have to cope with a diminishing supply rate of the resource that has been of paramount importance to our high-tech existence."

"Humans collectively must ultimately face the uncomfortable question of whether Earth’s natural systems can support 8 billion or more people at a modern standard of living. Since the resource footprint of a U.S. citizen is at least four times that of the global average, the key question is whether the planet can support an increase in material throughput four times higher than present when the strain is apparent already. As noble as it may be to wish [for] a modern living standard for an eventual ten billion or more people, it is likely that committing to such a course could result in more human suffering than would transpire under the adoption of more modest goals. The responsible path is to reduce global resource dependencies and abandon the imperative for growth starting now."

"Even something as seemingly altruistic as health care selfishly focuses on human health, to the exclusion and often direct detriment of ecosystem health. Are we really doing ourselves favors in the long term by making the destructive human enterprise healthier, more populous, longer-living, and therefore better able to carry out its damaging activities? If this sounds abhorrently anti-human, it’s because the human enterprise is currently relentlessly anti-planet. Anything that is anti-planet will dismantle ecosystems that serve as critical life support for humans, spelling failure for the human enterprise. So it’s really the human enterprise that is anti-human by way of being anti-planet. […] The best way to assure long-term prosperity is to forge a non-human-centric partnership with nature that does not always put short-term human interests above those of non-human elements of nature. Even “good” activities like health care therefore miss the boat in terms of building a better tomorrow."

"Since growth is an absurd short-lived anomaly, what about leveling out in population, resource use per capita, and adopting a steady-state economy? The problem here is that the rate at which we are depleting one-time resources today is unsustainable. We’re simply spending our bank account without paying attention to the balance and without any source of additional income. Most clearly, forests and wild spaces are down by a factor of two in the last 60 years and will be gone within 60 years at current rates of depletion. Before even getting to steady-state conditions, inevitable near-term increases in population together with sought-after increases in standards of living around the world spell an even shorter lifetime for critical habitats. Meanwhile, fisheries are failing in domino fashion; aquifers are being depleted at rates alarmingly higher than replacement; soils are degrading and arable land is lost; fertilizer depends on a finite resource; habitat loss is resulting in species extinctions far in excess of natural rates. Even the plunder of mineral resources in the seemingly infinite crust is getting harder, only a fleeting century or so into our spree. Sustaining present levels for even a few more centuries is a dubious (i.e., unsubstantiated) proposition. It is practically absurd to imagine sustaining present practices for 10,000 years. Humans simply have not yet demonstrated an ability to maintain a technological society without utter reliance on grossly unsustainable inheritance spending."

"Earth has never in its history had to contend with 8 billion fire apes, intelligent enough to have leveraged power by exploiting and burning one-time resources. We now operate outside the bounds and protections of evolution: in breach of contract, without a map to success. What could possibly convince us that this fireworks show—which has not even come close to standing the test of time—can maintain anything like its current resource impact for the long haul? Humans have demonstrated convincingly that we can live in a primitive state for hundreds of thousands of years. Our present mode is a few-century flash, supported almost entirely by inheritance-spending. Arguing that we have found a new normal is a precarious position that I would not be eager to defend. Parties end. Fireworks shows end. Why would our flash be any different? It’s not just guesswork: what other outcome could result from rapid resource exploitation on a finite planet?"

"We face unprecedented pressures on resources and on our environment, as human population and standard of living both surge on a finite planet. Nature will not allow this trend to continue indefinitely."

"Human population will not be allowed to grow [indefinitely]. Even small growth rates will step up pressure on natural resources, and Earth can only support so much, long-term. Independent of what the “right” number is, once settled, we will not be able to dial it up without imperiling the hard-won success. Even under steady human population, any increase in resource use per person will also not be compatible. In general, growth leads to a dead end: to failure."

"As a jarring illustration of our tendency to value the human side over the prerequisite physical/ecological side, imagine that somehow we manage to emerge from the coming centuries having established a truly sustainable existence. All resources are renewed by nature at the rate of extraction for human needs; population is steady and at a level just tolerable to the planet in terms of indefinite support. Diverse ecosystems are left to thrive in their natural states. But imagine that we are still plagued by cancer and other maladies, so that life expectancy is, say, 90 years. Then what if a team of researchers hits on a cure for (most forms of) cancer? Hurray! At last! Unambiguously good, right? Well, not so fast. All other elements held the same, longer life spans translate to a higher population, putting additional resource burdens on the planet that it cannot handle in the long term. In order to adopt and implement the cure for cancer, we would have to either deliberately reduce population or lower the standard of living to accommodate the change. All other considerations of the complex society about economic impacts, equity of distribution, legal and political facets, or interaction with religious belief systems must take a back seat to the most fundamental and important question: is this change physically viable on this finite planet in the long term?"

"People tend to prefer the narrative that we, ourselves, are the superheroes, and that our superpowers are not from the fossil fuel suit, but are cognitive in nature. Yet we have the same neural hardware (if not slightly downsized) as our prehistoric ancestors. The main cognitive revolution happened about 70,000 years ago when humans started to believe in things that do not exist (like spirits or potential future gains) that allowed large-scale coordination and shared identity to outcompete evolution’s more biophysical tricks of sharp teeth/claws, speed, strength, camouflage, poison, or overwhelming numbers. Global spread of homo sapiens and megafauna extinctions quickly followed, and it is at this point that the human experiment began to smolder: something was off. About 10,000 years ago, agriculture started and the first visible flame ignited. About 300–400 years ago, the Enlightenment lit a fuse by developing a scientific approach to understanding the world. It was not long before the fuse found fossil fuels and we now witness the predictable explosion that ensued. The explosion is breathtakingly rapid on any meaningful timeline, only appearing in slow motion to the few generations experiencing the phenomenon and thus seeming “normal.” So we can trace some part of our current planetary dominance to human ingenuity, but perhaps the lion’s share actually is attributable to the energy bonanza—as suggested by the dramatic change in the pace of innovation before and after the fossil transition."

"A plausible scenario for ecosystem collapse... is based on the fact that we currently support 8 billion people on a fossil-intense agricultural system. We have over-leveraged that finite resource to "borrow" millions of years of eco-services (photosynthetic energy) and now host a population that probably never could have existed in ecological equilibrium. Even if fossil fuels were not going away, it seems likely we would see continued erosion of the globe's ability to support this current unsustainable mode. We have already lost about half of the wild animal life in my lifetime: is that halfway to collapse? Take away the fossil fuels, and I imagine over-hunting and rapid deforestation will take an enormous toll on ecosystem health."

"[It] is truly alarming from an ecological point of view: not only has the human population grown like gangbusters, but the level of affluence per person has soared by an even larger factor."

"The dream of eventually having 10 billion people living at American standards completely ignores the glaring fact that we seem to be circling the drain even at today’s impact level (i.e., overshoot). How could we possibly entertain the factor-of-five increase in resource demand that would accompany a realization of “the dream?” It seems delusional… and likely to turn into a nightmare if pursued."

"Human population is going up… We’re not exactly doing the planet (or ultimately ourselves) any favors presently. Will adding more humans that subscribe to our current cultural model somehow make the situation better? Will improving standards of living (thus increasing resource demand) mysteriously turn things around? It’s hard to see how—not without enacting a whole new model."

"Increasing the standard of living of a growing population makes today’s ecological pressures look adorable."

"It is easy to get caught up in the heady whirlwinds of modernity. We have accomplished amazing feats in these past few centuries, and our extrapolative minds envision a continued acceleration. Given that our life span overlaps only a portion of the tale, it is easy to lose the context that our boom (the Industrial Revolution and what followed) is almost entirely due to fossil fuels. This energy surge in turn powered a surge in material access and economic activity (and human population) in what is perhaps fittingly described as a fireworks show."

"There is no way we could keep going as we have been. The increase in human population in the 1990s has exceeded the total population in 1600. The population has grown more since 1950 than it did during the previous four million years. The reasons for our recent rapid growth are pretty clear. Although the Industrial Revolution speeded historical growth rates considerably, it was really the public health revolution, and its spread to the Third World at the end of the Second World War, that set us galloping. Vaccines and antibiotics came all at once, and right behind came population. In Sri Lanka in the late 1940s life expectancy was rising at least a year every twelve months. How much difference did this make? Consider the United States: if people died throughout this century at the same rate as they did at its beginning, America's population would be 140 million, not 270 million."

"Babies are the enemies of the human race... Let's consider it this way: by the time the world doubles its population, the amount of energy we will be using will be increased sevenfold which means probably the amount of pollution that we are producing will also be increased sevenfold. If we are now threatened by pollution at the present rate, how will we be threatened with sevenfold pollution… distributed among twice the population? We'll be having to grow twice the food out of soil that is being poisoned at seven times the rate."

"It's going to destroy it all. I use what I call my bathroom metaphor. If two people live in an apartment, and there are two bathrooms, then both have what I call freedom of the bathroom, go to the bathroom any time you want, and stay as long as you want to for whatever you need. And this to my way is ideal. And everyone believes in the freedom of the bathroom. It should be right there in the Constitution. But if you have 20 people in the apartment and two bathrooms, no matter how much every person believes in freedom of the bathroom, there is no such thing. You have to set up, you have to set up times for each person, you have to bang at the door, aren't you through yet, and so on. And in the same way, democracy cannot survive overpopulation. Human dignity cannot survive it. Convenience and decency cannot survive it. As you put more and more people onto the world, the value of life not only declines, but it disappears. It doesn't matter if someone dies."

"We are a plague on the Earth. It’s coming home to roost over the next 50 years or so. It’s not just climate change; it’s sheer space, places to grow food for this enormous horde. Either we limit our population growth, or the natural world will do it for us, and the natural world is doing it for us right now."

"The success of modern medicine is today so great, that millions of people are kept alive - if not cured - who in earlier days, and with less scientific aptitude, would normally have died. In this developed skill and knowledge, and in this aptitude in the care of the physical mechanism, is today to be found a major world problem - the problem of overpopulation of the planet, leading to the herd life of humanity and the consequent economic problem - to mention only one of the incidental difficulties of this success. This "unnatural" preservation of life is the cause of much suffering, and is a fruitful source of war, being contrary to the karmic intent of the planetary Logos. With this vast problem, I cannot here deal. I can only indicate it. It will be solved when the fear of death disappears, and when humanity learns the significance of time and the meaning of the cycles."

"As we slide seamlessly from 7 billion to 8 billion humans, each generation more powerful, polluting, and destructive than the previous, I have to wonder whether one century is too much time to allow a “natural” progression into negative population growth, or whether the biodiversity damage a century like this one will inflict could be incalculable and irreversible, if not terminal for us. Think about the honey bees and hummingbirds. Think about the sudden absence of insects we are seeing all over the world, and how that soon may affect populations farther up or down the food chain. Now, Mr. Biotech Billionaire, are you serious about populating the world with thousands or millions of bicentiniarians [sic] and tricentinarians [sic]?"

"Whereas the unconscious operations and blind forces of the planet have provoked turbulent changes over the last 4.5 billion years of earth’s evolutionary history, now change is being directed by a conscious and volitional agent – "humanity." We cannot speak of humanity equally, to be sure, as the problem was caused by the industrialized capitalist West and the poorer nations who contributed least to climate crisis will be hit the hardest. But nations such as China, India, and Brazil are major contributors, and the cumulative impact of 7.5 billion people on the planet is causing extinction and collapse everywhere. The stability of the Holocene is now gone, changes are accelerating beyond our understanding and control, and chaos waits at our door."

"The geometric growth rate of humans is unprecedented and never in the history of the earth has a single species grown to such bloated proportions, completely out of balance with living systems. The problem is only worsening. On conservative estimates, the human population is expected to swell upwards to 8–10 billion by 2050, and perhaps expand significantly by 2100. Human population growth represents a crisis of the highest order, but of course, it is only one aspect of multiple crises -- including species extinction and climate change -- merging together in a perfect storm of catastrophe that forms the daunting challenges facing humanity in the Anthropocene."

"Currently, the operation of our present industrial civilization is almost wholly dependent on access to huge amounts of fossil fuels. It is important to understand that fossil fuels, especially oil, are not simply used to manufacture and propel passenger automobiles or trucks. They also facilitate the mass assembly of tractors, plows, irrigation pipes, and pumps and then turn around and power them also. They constitute the chemical base of many crucial fertilizers and pesticides. They are also the building blocks of agricultural plastics. They refrigerate perishables. In short, the modern industrial agriculture system could not function without copious amounts of fossil fuel. In the absence of fossil fuel-based industrial agriculture, world food production would plummet to a scale completely inadequate to sustain our current population size, let alone the net addition of over 80 million more people each year. The other side of the coin is that when humans co-opt the extraordinary power found in fossil fuels, we become “overpowered” – and that is how we are over-powering the Earth’s biosphere. We cannot destroy rainforests at the rate of several football fields per minute, trawl the deep oceans, attempt mass-scale aqua-culture, fragment habitat with asphalt roads, or construct miles and miles of urban sprawl without the power of fossil fuels. In summary, fossil fuels underwritten both our population size and growth and our discretionary (over)consumption."

"In my opinion, you have out-of-control population growth, and you have fewer and fewer [resources]—we are heading for the biggest train wreck our civilization has ever come across ever. Ever. And I think that within 40 or 50 years, we’ll be there. If your population curve is on an exponential growth, and the resources are on an exponential decline, what happens first is you get increases in wealth discrepancy, which means that you get rich pockets of gated communities with security guards outside them, and you get more and more poverty outside that area. And the resources go down, and people start having resource wars over water and food and agriculture and arable land, and then you have Joburg in 2050. And you can see signs of it everywhere. It’s just overpopulation and lack of resources. We just aren’t in control of our destiny."

"... Reverend THOMAS MALTHUS' prediction made in 1798—that man would reproduce himself into a condition of "misery and vice" because of the growing imbalance caused by the multiplication of his own numbers by geometric progression, while his food supply was increasing arithmetically—is as valid today as when it was made. He was a visionary and saw clearly the monster of overpopulation. The only error in his prediction was one of a "few seconds on the clock of human occupancy of the earth". We, agriculturists, can buy at most a few decades of time in which to bring population growth into successful balance with food production."

"It seems self-evident that our fundamental predicament of ecological overshoot is a direct result of humanity’s growth with too many people consuming too many resources and producing too many waste products for a finite planet dependent upon healthy ecological systems. And while this doesn’t require much explanation for those who acknowledge that we live upon a world with finite resources and limited capacity to compensate for our waste production, there are still many who believe that Homo sapiens’ rather unique cognitive abilities and technological prowess can and will ‘solve’ the many challenges we appear to be encountering as we reach and surpass the planetary limits of our relatively recent explosive growth, global expansion, and industrialisation."

"All living species must take from nature to survive, and we are no different. But unlike other species, there seems to be no end to our quest for food, comfort, shelter, sex — the fundamental necessities of survival that are now pursued in overdrive, far beyond our existential needs. We are compelled to progress, and have extracted resources from the land since we first stood on two feet. The entire twentieth century has been a revving up of this large consumptive engine, and this insatiable human striving has assaulted the very planet that sustains us. In a very short period of time, humankind, with its population explosion, industry and technology, has become an agent of immense global change. What this civilization leaves in the wake of its progress may be an opened and emptied Earth. But in performing these incursions, we also participate in the unwitting creation of gigantic monuments to our way of life."

"Global biodiversity decline is best understood as too many people consuming and producing too much and displacing other species. Wild landscapes and seascapes are replaced with people, our domestics and commensals, our economic support systems, and our trash."

"During the past hundred years, Homo sapiens population increased from 2 billion to nearly 8 billion and the United Nations (2019) projects an increase of 3 billion more by 2100, unless steps are taken to reduce this population growth. Ignoring this projected increase means ignoring a major driver of the unfolding biodiversity crisis; accepting current bloated human numbers as an appropriate status quo means accepting a biologically impoverished planet."

"Thomas Malthus, an eighteenth-century economist, once predicted that because our population size increases exponentially while our food supply increases arithmetically, our population will one day exceed our ability to sustain it. While this has now been disproven with the creation of processed foods and genetically modified organisms, [Peter] Farb’s paradox may hold true. Because Earth’s population is growing, we increase our food production. Then, because we have a surplus of food, people are more well-nourished, leading to higher life expectancies and lower infant mortality rates, and people are able to have more children. This cyclical paradox is not healthy for our planet because while we may be able to sustain our growing population’s appetites, our other important resources, such as water and oil, are dwindling. To have a sustainable population size, we should be reproducing at a replacement rate, much like Denmark and Japan are."

"Today [hu]mankind is locked into stealing ravenously from the future. Famine in the modern world must be… one of several symptoms reflecting a deeper malady of in the human condition—namely, diachronic competition, a relationship whereby contemporary well-being is achieved at the expense of our descendants. By our sheer numbers, by the state of our technological development, and by being oblivious to differences between a method that achieved lasting increments of human carrying capacity [agriculture] and one that achieves only temporary supplements [reliance on fossil fuels and other mined substances], we have made satisfaction of today's human aspirations dependent upon massive deprivation for posterity."

"We are already living on an overloaded world. Our future will be a product of that fact; that fact is a product of our past. Our first order of business, then, is to make clear to ourselves how we got where we are and why our present situation entails a certain kind of future. […] It is the story of a world that has again and again approached the condition of being saturated with human inhabitants, only to have the limit raised by human ingenuity. The first several rounds of limit-raising were accomplished by a series of technological breakthroughs that took almost two million years. These breakthroughs enabled human populations repeatedly to take over for human use portions of the earth’s total life-supporting capacity that had previously supported other species. The most recent episode of limit-raising has had much more spectacular results, although it enlarged human carrying capacity by a fundamentally different method: the drawing down of finite reservoirs of materials that do not replace themselves within any human time frame. Thus its results cannot be permanent. This fact puts mankind out on a limb which the activities of modern life are busily sawing off."

"Scarcely more than two generations had tasted the fruits of industrialization when the growth of population was still further accelerated by truly effective death control. The role of microorganisms in producing diseases was discovered. In 1865 the practice of antiseptic surgery began. It serves... as a reasonable demarcation of the beginning of an era filled with related breakthroughs in medical technology: hygienic practices, vaccination, antibiotics, etc. The total effect of this recent series of achievements has been to emancipate mankind more... from the life-curtailing effects of the invisible creatures for which human tissues used to serve as sustenance. Like other prey species newly protected from their predators, we have been fruitful and have so multiplied that we have much more than "replenished" the earth with our kind."

"People displayed either persistent ignorance of the carrying capacity concept or naive faith that carrying capacity could always be expanded, [and] that limits could always be transcended. Such an assump­tion seemed to underlie the stubborn refusal of capitalists and Marx­ists alike to acknowledge that the myth of limitlessness had, at last, become obsolete. There was also the assumption that further ad­vances in technology would necessarily enlarge carrying capacity, not reduce it. Enlargement of carrying capacity had been the role of tech­nology in the past; however… there has been a reversal of this role in the industrial era. Technology has en­larged human appetites for natural resources, thus diminishing the number of us that a given environment can support."

"[Hu]man[s]... have imagined... [themselves] to be more unlike other mammals than [t]he[y] really... [are], so when human behavior has shown these same characteristics, various other explanations have been put forth which have obscured the significance of population pressure itself. In the twentieth century, with human numbers enlarged and resource draw­down becoming significant, [hu]man[kind] went to war. [T]he[y] rioted in the streets. [T]he[y] committed more... crimes of violence. [...] [Their] political atti­tudes polarized and [t]he[y] created totalitarian governments, some of which gave license to sadistic tendencies. A generation gap widened and deepened. In spite of earnest efforts by humane activists to inhibit racism and to rectify economic inequality, disparities between people remained and animosities became more virulent. Standards of de­cency in behavior toward others and expectations of considerate self-­restraint were eroded and degraded in many places."

"We need to realize the "load" with which we humans burden the planet's ecosystems consists of more than just a population number. People living by different cultures not only reproduce at different rates; they impose very different per capita ecological impacts. Culture includes a population's technology and people's ways of organizing themselves. Each of us living in a "developed" country (i.e., industrialized far beyond anything conceivable to Malthus) has an enormously greater resource appetite and environmental impact than does each resident of a so-called "developing" country. For our grossly unsustainable manner of living, 6 billion is far too many."

"Life has now entered a . This is probably the most serious environmental problem, because the loss of a species is permanent, each of them playing a greater or lesser role in the living systems on which we all depend. The species extinctions that define the current crisis are, in turn, based on the massive disappearance of their component populations, mostly since the 1800s. The massive losses that we are experiencing are being caused, directly or indirectly, by the activities of Homo sapiens. They have almost all occurred since our ancestors developed agriculture, some 11,000 y ago. At that time, we numbered about 1 million people worldwide; now there are 7.7 billion of us, and our numbers are still rapidly growing. As our numbers have grown, humanity has come to pose an unprecedented threat to the vast majority of its living companions."

"We are in the sixth mass extinction event. Unlike the previous five, this one is caused by the overgrowth of a single species, Homo sapiens."