How to Stop the Sixth Extinction: A Critical Assessment of E. O. Wilson’s Half-Earth

By Kamran Nayeri, May 14, 2017

“The only solution to the ‘Sixth Extinction’ is to increase the area of inviolable natural reserves to half the surface of the Earth or greater.  This expansion is favored by unplanned consequences of ongoing human population growth and movement and evolution of the economy now driven by the digital revolution. But it also requires a fundamental shift in moral reasoning concerning our relation to the living environment.” (Wilson, 2016, p.167)

Introduction

The anthropogenic Sixth Extinction is an existential threat to much of life on Earth, including the human species.  In this essay, I critically examine the renowned entomologist, naturalist, and conservationist E. O. Wilson’s proposal in his recent book, Half-Earth: Our Planet’s Fight for Life(2016), to stop and reverse it.  In section I, I will outline what is meant by biodiversity and why it matters, and provide the basic facts about the Sixth Extinction and its salient causes.  In section II, I will outline Wilson’s proposal identifying tensions in his arguments for its efficacy.  In particular, I will show the tension between Wilson’s love for the natural world and his knowledge of biology and ecology on one hand and his inadequate understanding of human history, in particular, the capitalist civilization, which results in wishful thinking.  The Half-Earth proposal is necessary but not sufficient for stopping and reversing the Sixth Extinction. Finally, I conclude with a brief outline of what I consider to be necessary in order to make Wilson’s proposal effective.

I

Biodiversity and why it matters

In 2011, Boris Worm and his fellow researchers at Dalhousie University devised a new way to estimate the number of species, both known and undiscovered.  By this method, the number of species in the animal kingdom that exists today was estimated to be “at a quite reasonable 7.7 million” and the total number in the Eukarya, which include plants, algae, fungi, and many kinds of eukaryotic microorganisms, came “to approximately 8.7 million, give or take a million.” (Wilson, 2016, pp. 22-23)  Still, Wilson adds that the “Dalhousie method might undershoot the mark.” (ibid. p. 23)  On May 24, 2016, Kenneth Locey and Jay Lennon reported in the Proceedings of the National Academy of Sciencesthat using a global-scale compilation of microbial and macrobial data, they have uncovered relationships of commonness and rarity that scale with abundance at similar rates for microorganisms and macroscopic plants and animals. They then use other techniques to show that the world is home to about 1 trillion microbial species.  (Locey and Lennon, 2016, for a discussion, see, Pedrós-Alió and Manrubia, 2016)  To appreciate this biodiversity, we must recall how life originated on Earth and has evolved, and to remember that despite many possible planets that could harbor life we still know of no others that actually do. Life on Earth is still a unique experience in the universe as far as we can tell today.  Homo sapiens who possess the amazing power of contemplation and reasoning that has enabled us to understand and appreciate the emergence and development of life on Earth could not have evolved without the expansion of biodiversity of life following The Age of Reptiles that ended 65 million years ago.  We still depend and will continue to depend on the flourishing diversity of life that provide us with life support (Wilson, 2016, pp. 11-18, Washington, 2013). 

Mass extinctions of species: a rare phenomenon

It would be no surprise that some of these species go extinct as species extinction is a natural evolutionary phenomenon. In fact, ninety-nine percent of species that existed in 3.8 billion years of life on Earth have disappeared.  However, as Wilson points out (ibid. p. 63), the great majority of these didn't simply die-off. They evolved into multiple new species each fit to a niche in the changing environment. What is more relevant to our concern is the truly apocalyptic extinction event in which 50–90% of species were eliminated relatively quickly.  These are the Ordovician, 490–443 million years ago (mya), Devonian (417–354 mya), Permian (299–250 mya), Triassic (251–200 mya), and Cretaceous (146–64 mya) periods. The last of these ended the Age of Reptiles and began the Age of Mammals.   On average, the five apocalyptic extinction events have been spaced out by some 100 million years and it has taken about 10 million years for biodiversity to recover after such apocalyptic extinction events.  

How do we know that the biosphere is experiencing an anthropogenic Sixth Extinction?   By comparing the extinction rate before the rise of humans and its rate after their spread across the globe.  Paleontologists and biodiversity experts have estimated that before the emergence of humanity about two hundred thousand years ago, the rate of species extinction was one to ten species per one million per year (E/MSY).  This is called “the background extinction rate.” In contrast, since the spread of humanity extinction rate has accelerated up to 100 to 1,000 E/MSY today. Thus, scientists conclude that we are in the process of the Sixth Extinction.  However, the situation may be even direr: one recent study concludes  "that typical rates of background extinction may be closer to 0.1 E/MSY. Thus, current extinction rates are 1,000 times higher than natural background rates of extinction and future rates are likely to be 10,000 times higher.” (De Vos, et. al., 2015)

Causes of the Sixth Extinction

Paleontologists and biodiversity experts associate the acceleration of the rate of species extinction with the spread of humans and our increasingly larger “ecological footprint.” The "ecological footprint" is a murky concept colored by the context of its use.  For our purpose, let’s define it as ecological impact due to Our Way of Life.(see, endnote 1)  I will come back to this a little later. 

Evidence for anthropogenic extinction events goes back 50,000 years to the time when humans were migrating out of Africa and spread across the planet.  Extinction rates increase as the number of people and our “ecological footprint” increase and greatly accelerate in the past two centuries with the spread of industrial capitalism and exponential population growth (Sodhi, et. al. 2009). 

As I will explain in a moment, humans, still few in numbers, began to hunt megafauna into extinction in prehistory soon after migration out of Africa that began 80,000 to 50,000 years ago.  But when our ancestors became producers with the advent of agriculture, the mode of production also became the mode of articulation of Our Way of Life and how it degraded and destroyed ecosystems accelerating the global extinction rate.  

Hunter-gatherers 

Although hunter-gatherers hunted and fished for a million years, there are no indication that they contributed to the extinction of species.  That is, until about 50,000 years ago when humans were established on every continent except Antartica.  Then the big games start to go missing: 

“Australia lost most of its large animals first, about 46,000 years ago. North and South America saw a similar extinction wave 13,000 years ago. New Zealand, meanwhile, kept hold of its big-bodied animals until a mere 700 years ago…What links these points in time is simple: They mark the moment when humans arrived.” (Lynas, 2011, p. 33)

Not all experts agree that the hunter-gatherers were solely responsible.  They also blame climate change as the Ice Age began to come to a close. The larger species had a harder time to adapt. But in the last and best-documented mass extinction of the flightless birds and other animals in the Pacific in the Old Stone Age there is no doubt that humans were solely responsible.  Wright puts it this way: 

“The perfection of hunting spelled the end of hunting as a way of life. Easy meat meant more babies. More babies meant more hunters. More hunters, sooner or later, meant less game.  Most of the human migrations across the world at this time must have been driven by want, as we bankrupted the land with our moveable feasts.” (Wright, 2004, p. 39)

Wilson describes the extinction of land birds of the Pacific Islands in more detail:

“The land birds of the Pacific Islands have been the victims of another kind of apocalyptic force.  In sheer numbers of species lost, they have been the hardest hit of all vertebrate animals. The wave of extinction that began thirty-five hundred years ago with the arrival of humans in the western archipelagos—Samoa, Tonga, Vanuatu, New Caledonia, Fuji, and the Mariana—continued to nine to seven centuries ago through the colonization of the most remote islands of Hawaii, New Zealand, and Easter Island.  A few of the surviving species teeter on the brink of extinction today. Two-thirds of the non-passerine pacific birds, however, close to one thousand species, were extinguished. Thus some 10 percent of the birds species on Earth were wiped out during a single episode of colonization by relatively few groups of people.” (Wilson, 2016, pp. 38-39)

The first farmers and agrarian societies

The Agricultural Revolution that laid the foundation for civilization was based on a radically different attitude towards nature. While hunter-gatherers saw themselves as part of the ecosphere and largely co-existed with their natural surrounding, the early farmers gave up the hunter-gatherers’ ecocentric worldview for an anthropocentric worldview which justified a growing need for domination and control of nature.  On one hand, the early farmers and pastoralists domesticated plants and animals for exploitation, and on the other hand, they drove off or destroyed species that posed any potential danger to their way of life.  At the same time, they began replacing existing ecosystems with human-made landscapes on ever-larger scale and scope.  

While the transition to farming was driven largely by external factors (e.g. climate change) and early farmers were worse off than hunter-gatherers for an extended period, eventually, some succeeded to improve their lot by producing an economic surplus through the exploitation of animals and plants using improved techniques. This economic surplus made population growth possible and it laid the foundation for social stratification, subordination, and exploitation.  Thus, the Agrarian Revolution that was based on alienation from nature as manifested in the rise of anthropocentrism, laid the basis for social alienation.  In a most remarkable historical irony, anthropocentrism laid the basis for class societies where the ruling elites lived off the exploitation of nature facilitated by the exploitation of subordinated social classes and groups. 

Domination and control of nature (including subordination of classes and groups of humans) required the development of forces of production: technologies and know-how that gradually developed in the modern era into sciences (Bunch and Hellemans, 2004).  However, until the rise of capitalist modernity, agrarian societies remained largely depended on the exploitation of animals and plants and the pace of change was slow.  Thus, the population grew slowly and their way of life was less destructive of biodiversity, or when it was disastrous and some civilizations collapsed due to the ecological crisis, like the first agrarian civilization in Sumer, the scope of the disaster was limited. Moreover, it should be recalled that even in 1,400 much of the world was still not incorporated in regions of agrarian civilizations (Wolf, 1982).  The elites of the civilized parts of the world called people who lived outside their realm barbarians. They included foragers, pastoralists, horticulturalists, and small-scale farmers who often used semi-nomadic forms of swidden agriculture and still hunted and gathered some of their produce.

Capitalist modernity

The English Industrial Revolution (1760-1820), revolutionized forces of production and unleashed the powers that made the anthropocentric industrial capitalist civilization global.  In 1800 when the world population was about 0.9 billion, only 3 percent lived in urban areas. By 1900 the world population had increased to 1.65 billion of whom almost 14 percent were urbanites, although only 12 cities had 1 million or more inhabitants. In 1950, world population had reached 2.67 billion and 30 percent of them resided in urban centers. The number of cities with over 1 million people had grown to 83.  The world has experienced unprecedented urban growth in recent decades. In 2008, the world population was 6.7 billion evenly split between urban and rural areas and the number of cities with 1 million or more was 400. As of this writing in 2017, it has reached 7.5 billion and is expected to reach close to 10 billion by 2050.  Human population growth has become exponential due to three factors: 1) increases in food production and distribution, 2) improvement in public health (water and sanitation), and 3) medical technology (vaccines and antibiotics), along with gains in education and standards of living in many developing nations. 

If we use population growth and per capita income as proxies for “ecological footprint" (as Wilson does, see below), Angus Maddison’s calculations shed some light on how it has increased between the years 1,000 and 2,000: 

“[W]orld population rose 22-fold. Per capita income increased 13-fold, world GDP nearly 300-fold. This contrasts sharply with the preceding millennium when world population grew by only a sixth, and there was no advance in per capita income.

“Since 1820, world development has been much more dynamic. Per capita income rose more than eightfold, population more than fivefold.”  (Maddison, 2006, p. 19)

To understand how this progress of the anthropocentric industrial capitalist civilization has accelerated the Sixth Extinction let’s consider Haydn Washington’s (2013) discussion of energy flow and the food chain. Ultimately, all species live off energy that arrives on Earth via sunshine.  Through photosynthesis green plants (primary producers) convert solar energy into sugars. They consume about half of it for their own livelihood. What remains is called Net Primary Productivity (NPP).  The NPP is the basis for all animal life. Herbivores eat plants to gain energy for their livelihood (primary consumers). Some carnivores live off herbivores (secondary consumers).  Still, other omnivores eat secondary consumers (tertiary consumers).  The final link in the food chain is the decomposers that live off the organic matter of plants, herbivores, and carnivores.  In each step in the food chain, about 90% of the energy is lost. 

Washington citing Boyden (2004) writes: 

"The human species is now using about 12,000 times more as much energy per day as was the case when farming started; 90 per cent of this is a result of industrialization, 10 per cent to our huge growth in numbers.... The NPP of the land amounts to about 132 billion tonnes dry weight of organic matter in 1986. (Vitousek et al, 1986) Of these the then human population of 5.7 billion humans consumed directly just over 1 billion tonnes as food. In addition humans co-opted 43 billion tonnes (32 per cent) of total NPP in the form of wasted food, forest products, crop and forestry residues, pastures and so on.  Vitiusek et al. (1986) conclude:

“‘We estimate that organic material equivalent to about 40% of the present net primary product in terrestrial ecosystems is being coopted by human beings each year.  People use this material directly or indirectly, it flows to different consumers and decomposers than it otherwise would, or it is lost because of human-caused changes in land use.  People and the associated organisms use this organic material largely, but not entirely, at human direction, and the vast majority of other species must subsist on the reminder.  An equivalent concentration of resources into one species and its satellites has probably not occurred since land plants first diversified.’

“They also note that ‘humans also affect much of the other 60% of terrestrial NPP, often heavily’, thus our impact is not just limited to the 40 per cent of NPP we co-opt directly. The estimates in this classic 1986 study are conservative, and we are now 25 years further down the path of expanding population and impacts. However, other scholars use different methodologies and come up with different figures.... Whichever figure one uses, this remains a huge percentage of the net primary productivity of the planet that humans are appropriating.  Of course this appropriation is also increasing as population, and possibly more importantly per capita consumption , continues to increase. The high and increasing appropriation of NPP by humanity is clearly a fundamental stress on ecosystem health. NPP is the foundation of all ecosystems, so if we pull out too many blocks from the foundation to put on the ‘human pile’ eventually other structures (natural ecosystems) collapse.  And indeed they are..." (Washington 2013, p. 12-13).

Of course, there are multiple anthropogenic causes of the Sixth Extinction. Conservation biologists often use the acronym HIPPO for a quick recall of the most ruinous.  In the order of importance, these are habitat destruction, invasive species (introduced by humans), pollution, population growth and overhunting. (Wilson, 2016, pp. 57-58)

How can this assault on the world ecosystems have gone largely unnoticed by the public until the recent decades?  The answer lies in the anthropocentrism of capitalist modernity.  Sociologists Catton and Dunlap (1980, p. 34, Table 1, column 1) summarize the “dominant western worldview,” that is, the modernity as an ideology, as follows:

• People are fundamentally different from, and superior to, all other creatures.
• People are masters of their destiny and can use the rest of nature in any way they choose. (see, endnote 2)
• The world is an endless resource and thus provides unlimited opportunities.
• Human ingenuity will solve all problems, and progress needs never cease.

II

Wilson’s proposal to stop and reverse the Sixth Extinction

Wilson predicates that by the end of the century the Sixth Extinction becomes unstoppable. In the past mass extinction events, anywhere between 50 to 90 percent of existing species went extinct.  Thus, humanity faces an existential crisis: How can we stop and reverse the Sixth Extinction?  

Wilson’s proposal begins from his critique of the conservation movement which has won many battles but will lose the war against the Sixth Extinction because, as he notes, it lacks a comprehensive plan of action. Wilson argues that what needed to set aside at least half of the Earth’s land and sea as wildness reserves that cannot be disturbed by human activity.  (Wilson, 2016, pp. 185-188)  Earlier in the book, Wilson actually identifies the precise regions of the Earth that must be included in such Half-Earth wildness reserves. (ibid. pp. 133-154) These regions are selected because they are already least disturbed parts of the planet and they contain at least 85 percent of the world’s known species.  

However, while Wilson’s case for the necessity of setting aside at least half of the planet for wildness is based on the best available knowledge in conservation biology and ecology, he fails to show its sufficiency. As I explained in part I, the extinction rate has accelerated since the rise and spread of the anthropocentric industrial capitalist civilization. Can we hope to return to the pre-human background extinction rate of one to ten species per million per year while keeping the present capitalist civilization intact?  Wilson simply dodges this crucial question. Instead, he attempts to make the case for the efficacy of his proposal focusing on prospects for a reduction of the “ecological footprint” in the rest of the century, the immediate cause for the acceleration of the rate of extinction.  To simplify, Wilson focuses on the two major contributing factors to the rapid increase in the “ecological footprint”: population growth and per capita consumption. (see, endnote 3)  

Although the human population has grown exponentially since 1800 contributing to the acceleration of the extinction rate, it has stabilized in the more economically advanced regions where “women have gained some degree of social and financial independence.” (Wilson, 2016, p. 190)  Still, world population continues to grow rapidly in some regions “including Patagonia, the Middle East, Pakistan, and Afghanistan, plus all of sub-Saharan Africa exclusive of South Africa” due to high fertility (on average three surviving children for each woman).  The 2015 revised UN population report estimates that by 2100, the world population would be 11.213 billion and it may then stabilize.  Wilson realizes that forecasted population growth may be contributing to the acceleration of the extinction rate, especially since the bulk of this increase in population would be in the Global South where people need a higher standard of living.  He tries to get around this problem by arguing that the “ecological footprint” will shrink because of “the evolution of the free market system, and the way it is increasingly shaped by high technology.” (ibid. p. 191)

“The products that win competition today, and will continue to do so indefinitely, are those that cost less to manufacture and advertise, need less frequent repair and replacement, and give highest performance with a minimum amount of energy. Just as natural selection drives organic evolution by competition among genes to produce more copies of themselves per unit cost in the next generation, raising benefit-to-cost of production drives the evolution of the economy.  Almost all of the competition in a free market economy, other than in military technology, raises the average quality of life.” (ibid.)

Of course, in the conservation and ecology movement, Wilson is by no means alone in placing his hope for saving the world in technology and the magic of the capitalist market.  As Foster and Clark note in “The Planetary Emergency”:

“Faced with such intractable problems, the response of the dominant interests has always been that technology, supplemented by market magic and population control, can solve all problems, allowing for unending capital accumulation and economic growth without undue ecological effects by means of an absolute decoupling of growth from environmental throughput.” (Foster and Clark, 2012) 

Wilson naturalizes the “free market economy” by comparing it with the evolutionary natural selection. He argues capitalism is on the verge of transition to “intensive economic growth” using natural resource-saving technologies thereby reducing the “ecological footprint” despite increases in the population and the likely increases in per capita consumption.  

What is the specific basis for Wilson’s optimism? He cites the so-called Moore’s Law, the observation by Gordon Moore in a paper published in 1965 that the number of transistors in a dense integrated circuit doubles approximately every two years, as evidence for the new economy he envisions.  It is true that given lower costs and improved performance of integrated circuits widely used in electronics, some economists had argued that the “information economy” would herald a new and improved phase of economic growth.  However, leading macroeconomists and scholars of productivity growth (like Robert Gordon, 2000) disagreed and they have been vindicated by the subsequent course of the U.S. and the world economy. 

Wilson also quotes a passage from The Royal Society’s People and the Planet report (2012) about “decoupling economic activity from environmental impact.” He points to synthetic biology, nanotechnology, and robotics as the drivers of the new economy and the supposed decoupling.  But The Royal Society report merely aspires for such decoupling, not that it is an impending fact: “Decoupling economic activity from material and environmental throughputs is needed urgently for example by reusing equipment and recycling materials, reducing waste, obtaining energy from renewable sources, and by consumers paying for the wider costs of their consumption.” (The Royal Society, 2012, p. 8).   Finally, Wilson’s enthusiasm for synthetic biology, nanotechnology, and robotics as the pioneer of decoupling may be misguided as well.  It is true that there are technology enthusiasts who argue for never ending economic progress (it is anthropocentric capitalist modernity after all. See, for example, the report by Roco and Bainbridge, 2002, commissioned by the National Science Foundation and Department of Commerce).  But then again, other experts neither envision a new wave of economic growth nor a decoupling of growth from intensive natural resource use. (e.g., see, Gordon, 2016; Krugman, 2016). (see, endnote 4) In fact, there are good reasons to believe capitalism will continue increasing the “ecological footprint” because it is driven by the requirement of ever more accumulation of capital, hence ever more quest for growth through the commodification of society and nature.  Thus, efficiencies gained by improvement in science and technology may end up increasing consumption not reducing it as first noted by William Stanley Jevons in the case of the British coal industry in the nineteenth century (for a discussion, see, Foster, Clark, and York,  2010) 

So, it is fair to conclude that Wilson's case for shrinking the “ecological footprint” by relying on the workings of the capitalist economy is spurious.  

Thus, Wilson must rely on a change in ethics. Preservation of biodiversity, he tells us, “also requires a fundamental shift in moral reasoning concerning our relation to the living environment.” (ibid., p.167) But what is the basis for this “moral reasoning?” and how does it fit with the anthropocentric capitalist modernity that Wilson embraces? He does not say.  Let us now turn to issues that Wilson needed to tackle but did not. 

III

How to save biodiversity and the world
Returning to wildness

As I outlined earlier, civilization has been built on the basis of domestication which is the subject of the two-volume book Darwin published in 1868, The Variation of Animals and Plants under Domestication (Volume 1, Volume 2).  Domestication can be defined as “the evolutionary process whereby humans, modify, either intentionally or unintentionally, the genetic makeup of a population of plants or animals to the extent that individuals within the population lose their ability to survive and produce offsprings in the wild" (Blumler and Byrne 1991, p.24, cited in Barker 2006, p. 2). Wilson’s discussion of biodiversity loss focuses on how humans have marginalized or eradicated wild species.  But he fails to discuss the role of domestication in increases in the rate of extinction. Driscoll and his co-authors note the foundational role of domestication in the rise and spread of civilization which is responsible for the Sixth Extinction:

“Domesticating animals and plants brought surpluses of calories and nutrients and ushered in the Neolithic Revolution. However, the Neolithic Revolution involved more than simple food production; it was also the growth of an agricultural economy encompassing a package of plant and animal utilization that allowed for the development of urban life and a suite of innovations encompassing most of what we today think of as culture. Much of modernity is an indirect consequence of artificial selection. The plow has come to symbolize the Neolithic Revolution, but viewing history in the light of evolution we see that it was intelligently designed changes to the genetic composition of natural biota that made the real tools. In some sense, Neolithic farmers were the first geneticists and domestic agriculture was the lever with which they moved the world.” (Driscoll, et. al., 2011). 

Clearly, artificial selection competes with and undermines natural selection in many ways. Gray wolf population in the lower 48 states in the United States stands at 5,178 in 2017 due to hunting, largely to protect ranchers interests.  Gray wolf is a keystone species for its unique and crucial role in how the ecosystem functions.  Without the gray wolf, the ecosystem is degraded and other species are lost as well.

The process of artificial selection has led to the prominence of relatively few species of plants and animals in the world today: only a dozen crops (banana, barley, maize, manioc, potato, rice, sorghum, soybean, sugar beet, sugar cane, sweet potato, and wheat) make up more than 80 percent of the world’s annual crop production (Diamond, 1997, p. 132) and only five farm animals, cow, sheep, goat, pig, and the horse, make up the bulk of the large domesticated species. (Barker, 2006, p. 1)

While wild megafauna, often keystone species, are rapidly going extinct humans are raising, slaughtering and consuming many billions of farm animals each year at a huge cost to the biosphere.  In 2011, for example, the capitalist meat industry dominated by a handful transnational firms slaughtered more than 58 billion chicken (more precisely, 58,110,000,000), nearly 3 billion ducks (2,917,000,000), more than 1 billion pigs (1,383,000,000) worldwide. Other farm animals slaughtered for food numbered in hundreds of millions each: 654,000,000 turkeys, 649,000,000 geese and guinea fowl, 517,000,000 sheep, 430,000,000 goats and 296,000,000 cattle (Heinrich Böll Foundation, 2014, p. 15; for a discussion see, Nayeri, 2014). (See, endnote 5)

There are other domesticated animals whose population have exploded and their range expanded globally at the expense of wildlife.  There are at least 525 million dogs in the world (Coren, 2012) and the house cats population is estimated to be between 220 million and 600 million. Feral cats population is estimated to be about the same, prompting some to estimate the world total cat population at 1 billion.  Cats and dogs are known invasive species.  One recent study estimates that free-ranging domestic cats kill 1.3–4.0 billion birds and 6.3–22.3 billion mammals annually. (Loss, et. al., 2013)   

Thus, to preserve biodiversity we must stop and reverse domestication (see, Singer, 1975/2002, for thoughtful suggestions).  But domestication also entails ethical dilemmas. 

Ethics of Biodiversity

As I noted earlier, Wilson calls for a new environmental ethics but does not elaborate. In another essay devoted to Wilson’s sociobiology theory, I characterized Wilson as “an ecologically sensitive modernist” thinker whose view of the future of the humanity is colored by what he learns from evolution but not informed by any explicit theory of history and society (Nayeri, 2015b).  For Wilson “overcoming religious and non-scientific view of the world in favor of a scientific one, of rational mind over irrational mind, is the road to human fulfillment. He calls this the New Enlightenment which is an extension of his humanism.”  But despite its historically progressive role humanism is a modern variety of anthropocentrism.  Thus, the naturalist evolutionary biologist Wilson writes: 

“[H]umanity is far and away life’s greatest achievement. We are the mind of the biosphere, the solar system, and—who can say?—perhaps the galaxy….We will soon create simple organisms in the laboratory. We have learned the history of the universe and look almost to its edge.” (Wilson, 2012, p. 288)  

As if responding to Wilson's high praise for human intellectual achievements, Darwin writes: 

“[T]he difference in mind between man and the higher animals, great as it is, is certainly one of degree and not of kind. We have seen that the senses and intuitions, the various emotions and faculties, such as love, memory, attention, curiosity, imitation, reason, etc., of which man boasts, may be found in an incipient, or even sometimes in a well-developed condition, in the lower animals. (Darwin, 1871/1981, p. 105, emphasis added)

Today, we know far more about the narrowing of supposed differences that are claimed to set humans morally above other animals, and we have begun learning about self-awareness, communication, even intelligence in non-animal species (see, for example, Pollan, 2013, about the current research on intelligence in plants). 

The point is that evolutionary theory like life itself is ecocentric but anthropocentrism is a cultural point of view associated with the rise of agriculture and the spread of class societies which is deeply embedded in civilization. 

Thus, even Darwin fell victim to anthropocentrism. Francis Darwin, Charles Darwin’s daughter, writes that while slavery and cruelty to animals moved her father the most, he was firmly opposed to “the anti-vivisection agitation.” (Rachels, 1990, pp. 212-14)

With the growth of our knowledge of the lives of non-human animals, the field of ethics in our relations with them has also advanced. Rachels (1990) has used Darwin’s theory to argue for moral consideration for all animals.  He recalls that before Darwin the doctrine of “dignity of man” (or his superiority over the rest of nature) was defended either by the claim that “man is made in the image of God” or by the notion that “man is a uniquely rational being.”  Rachels painstakingly debunks both of these arguments in light of Darwin’s evolutionary theory. To replace the “dignity of man” doctrine, Rachels proposes the concept of “moral individualism.”  “How an individual should be treated depends on his or her own particular characteristics, rather than on whether he or she is a member of some preferred group--even the ‘group’ of human beings...This means that human life will, in a sense, be devalued, while the value granted to non-human life will be increased.”  (Rachels 1990:5)  By “devaluation” of human life, Rachels means the process of dethroning human beings as the apex of creation. It should be understood in the sense of leveling of hierarchical value systems as in the case of the fall of Apartheid in South Africa.  It was not so much “devaluing” the lives of white South Africans as it was for equality of all regardless of the color of their skin (race is not a biological category but a social construct).

Gary L. Francione, a philosopher and ethicist at Rutgers University, has made a persuasive case for the abolition of animal exploitation by arguing that animals are “persons” not “things.” The key to his argument is the right to the principle of equal consideration for animals: the ethical rule that we ought to treat like cases alike unless there is a good reason not to do so.  According to this principle, any moral theory that allows similar cases to be treated in a dissimilar way would fail to qualify as an acceptable theory.  (Francione, 2008, pp. 44-45) Criticizing the utilitarian animal rights position of Bentham that is the basis of Peter Singer’s well known work, Animal Liberation (1975), Francione notes that Bentham never questioned the property status of non-human animals under consideration: “Bentham’s error was perpetuated through laws that purported to balance the interest of property owners and their property.” (ibid., pp. 45-46).  As in slavery, where it was impossible to balance the rights of the slave with those of the slaveowner, there is no way to balance the right of non-human animals with those of their human owners (for an application of the principle of equal consideration, see, Nayeri, 2015a). Thus, commodification and ownership of non-human animals inherently preclude the principle of equal consideration, hence it precludes the possibility of sound moral judgment in our relationship with them. Therefore, Francione calls for the abolition of animal exploitation in the same sense that abolitionists called for an end to slavery: by ending the possibility of them being property.

Of course, Francione’s argument while radical with respect to the horrific treatment of non-human animals owned by humans excludes ethical consideration of animals that are not owned by those who commit acts of cruelty against them as in commercial and “recreational” hunting and fishing. And it does not extend the principle of equal consideration to non-animal species.  Yet, the evolutionary theory makes it clear that every species evolve not to excel others but to fit a particular niche in the ecosystem it inhabits. It is anthropocentric and anti-Darwinian to expect other species to excel in capacities acquired by one species, namely the Homo sapiens. In the Darwinian theory, there are simpler and more complex species. There are no superior or inferior species. In particular, being a more complex species does not make one superior. As Wilson points out, from the perspective of life on Earth humans are unimportant whereas insects are crucial (Wilson, 2006, pp. 26-36). 

A recent movement that is pertinent to this discussion is Deep Ecology that has been identified with the work of the Norwegian philosopher Arne Naess.  Naess’s philosophy builds on Spinoza’s that held that God and Nature are one and the same (Naess,  2008, pp. 230-251). On this basis, Naess adopts an ecocentric approach that he calls Ecosophy T close to the worldview of foragers.  He argues that every living being, human or not, has an equal right to live and blossom (Naess, 1989, pp. 164-65), a right that is not conditional on how humans perceive it. According to Naess, each person has her own ecosophy (philosophy of nature) that can become ecocentric based on experience and contemplation. To suggest just one example of such ethical approach to nature he and Sessions proposed an Eight Point Platformfor the Deep Ecology movement that seeks to address the planetary crisis. They are as follows:

• The well-being and flourishing of human and non-human life on Earth have value in themselves (synonyms: intrinsic value, inherent value, inherent worth). 

• These values are independent of the usefulness of the non-human world for human purposes. Richness and diversity of life forms contribute to the realization of these values and are also values in themselves. 

• Humans have no right to reduce this richness and diversity except to satisfy vital needs.

• The flourishing of human life and culture is compatible with a substantially smaller human population. The flourishing of non-human life requires a smaller human population.

• Present human interference with the non-human world is excessive, and the situation is rapidly worsening.

• Policies must therefore be changed. These policies affect basic economic, technological and ideological structures. The resulting state of affairs will be deeply different from the present.

• The ideological change will be mainly that of appreciating life quality (dwelling in situations of inherent value) rather than adhering to an increasing standard of living. There will be a profound awareness of the difference between bigness and greatness. 

• Those who subscribe to the foregoing points have an obligation directly or indirectly to try to implement the necessary changes.

Naess and Sessions invited others to draft their own platform or adopt theirs with revisions as they like. There could be and there are many ecocentric views of the world and all can contribute to the healing of the 10,000 old humanity’s rift with the rest of nature.  

Transcending anthropocentric industrial capitalism

Despite noting the Anthropocene (The Age of Man) early in Half-Earth and criticizing the Anthropocene ideology in the conservation establishment (extreme versions of ecomodernism), Wilson fails to place his proposal to stop the Sixth Extinction in the context of the planetary crisis (for a discussion of the planetary crisis, see, Rockström, et.al., 2009; Steffen, et. al., 2015)  This reveals a fatal flaw for Wilson’s proposal.  Even if it is adopted, runaway global warming will surely increase extinction rates even in wildness reserves of the world.  The same argument is valid for the climate justice movement: if the Sixth Extinction is allowed to become unstoppable then humanity may face extinction even if the greenhouse gasses are brought under control.  Thus, it is the Anthropocene that must be stopped and undone.  

But would there be the Anthropocene without anthropocentrism and a succession of class societies built on its basis to extract wealth from nature through the exploitation of labor using ever more powerful forces of production?  

The current discussion about the Anthropocene as a new geological epoch is motivated by our belated recognition of humanity’s impact on the planet. Although the matter is still under consideration by the geologists and other scientists, there is an emerging consensus that the year 1950 can be the marker for the onset of the Anthropocene epoch because of the radioactive particles scattered throughout the planet after the explosion of two atomic bombs in Hiroshima and Nagasaki. But other markers such as plastic pollution, soot from power stations, concrete, and even the bones left by the global proliferation of the domestic chicken are also under consideration.  The modern day driver of the Anthropocene is worldwide capitalist accumulation which over the past 250 years has employed science and technology to unleash forces of production never imagined before.  To undo the Anthropocene we must transcend the anthropocentric capitalist civilization.  

To illustrate this argument in relation to Wilson’s proposal let's reconsider the “ecological footprint.” One problem with the use of per capita consumption is that it masks how much of the world “ecological footprint”  is due to the tiny minority who constitute the core of the world capitalist class. According to the latest Credit Suisse report (2016), the richest 3.5 million people worldwide (o.7% of world population) control $116 trillion, or 45.6% of the world’s wealth, or more than $1 million each (of course, even in this group a tiny minority control much of the world capitalist wealth).  The poorest 3.5 billion people (73% of the world population) control only $6.1 trillion of wealth, or less than $10,000 in wealth each (Of course, a majority in this group have no wealth or even negative wealth, debt).  Thus, it is obvious that core of the capitalist class that roughly make up 0.7% of the world population is responsible for almost half (47%) the world "ecological footprint." To reduce the “ecological footprint” we must end the capitalist drive for accumulation of wealth, hence the profit-driven economy and economic growth. Only by transcending the anthropocentric capitalist civilization can we stop and reverse the Sixth Extinction.  

Also, a recent study by the Pew Research Center shows that 71% of the world's population remain low-income or poor, living off $10 or less a day (Kochhar, 2015).  Clearly, the living standards of the bulk of humanity, mostly living in the Global South, must be lifted to meet their basic needs.  If we move from a culture of having to a cultural being, the extreme accumulated of wealth by the top 0.7 of the world population, the core capitalist class, can be distributed among the 71% of the world population that are locked into poverty and inadequate income for a decent life.  To stop the Sixth Extinction and ensure human development, we must transcend the anthropocentric capitalist civilization in the direction of ecocentric ecological socialism.

Ecological socialism and nature

Wilson’s proposal would set aside at least half of the planet as wildness reserves but will maintain an anthropocentric capitalist civilization in the rest of the planet which he hopes would become good stewards of nature.  But the notion of human stewardship of nature is anthropocentric, a subject-object relation that sets humans apart and above the rest of nature.  Let's recall that the Sixth Extinction is not caused by our mismanagement of our relationship with nature but because of the drive to dominate and control it to enrich successive anthropocentric class-based civilizations.  If we learn to reverse course towards an ecocentric human society that loves and respects nature we do not have to act as its stewards.  Nature does not need any stewards. It is primary and we are secondary in fact. 

Thus, a key challenge in the transition to an ecocentric ecological socialism would be to arrive at a de-alienated, non-malignant relationship with the rest of nature. Instead of being “good stewards” of nature we must become a significant part of the biosphere that understands and appreciate every other part of it with love and respect. This is not a manager and managed, a subject and object, relationship. It is a relationship with the rest of nature based on environmental ethics consistent with a culture of being which our forager ancestors practiced instead of a culture of having the characteristic of the anthropocentric capitalist civilization.  Without such a cultural revolution, any socioeconomic transition to an ecological socialism is bound to fail.  This cultural revolution is already part of the resistance to the anthropocentric capitalist civilization as reflected in the struggle of indigenous peoples of Bolivia who cherish the rights of Mother Nature to the Standing Rock struggle of Native Americans against the North Dakota Access Pipeline who rely on their still heavily ecocentric-influenced culture. In their prayers, they convey the wisdom of their ancestors (see, for example, the Haudenosaunee, Iroquois, Thanksgiving Address).  I cite these cases because they are not based on science-driven ethical principles as discussed earlier but on ecocentrist wisdom of indigenous peoples of the world. In fact, in an ecocentric ecological societies science would be a source of wisdom not of satisfaction of human curiosity and the anthropocentric drive to dominate and control nature. 

To undo the Anthropocene, hence the Sixth Extinction, climate crisis, and other planetary crises, a transition to a world with a significantly lower human population is needed. The maximum human population worldwide and in each bioregion must be based on the principle of do-no-harm to the ecosystems while ensuring adequate resources for human development. This radical lowering of the human population will require empowering women and democratic family planning.  Simultaneously, a radical economic restructuring must be undertaken to reduce the “ecological footprint” drastically in the Global North but increasing standard of living in the Global South and for the in-need-population in the Global North. Taking the case of the U.S. economy for illustration, in the sphere of production huge sections of manufacturing like the military-industrial complex, chemical, and petrochemical industries (fossil fuels), and industrial agriculture will be phased out as quickly as possible.  Finance, insurance, and real estate industries will be drastically downsized and what is left as necessary would be run by workers and consumer councils. This will eliminate management services industry. Wholesale and retail trade and international and national transportation will be eliminated or minimized as the economy become local and regional. Health care, education, culture, housing, and art and culture will expand but becomes decentralized as much as possible. Agriculture will be replaced by non-animal using permaculture and agroecology.  Technology will be cut back, leaving only what is needed for human development that is not harmful to nature.  Free time will increase for everyone. Work will be joyous as labor becomes de-alienated and creative. The social agency for ecocentric ecological socialist revolution, a worldwide movement, would be the youth and working people.  They alone can decide how quickly the transition can and should happen while remembering that we are racing against time! 

Of course, these suggested radical and massive changes are too general to anticipate all the challenges.  It will take much more to undo 10,000 years of anthropocentric class civilizations in favor of an ecocentric ecological socialist one.  Could this happen? 

If my argument in this essay is broadly correct, there is no other way out of the crisis of civilization.  It is entirely possible that a transition to an ecocentric ecological socialism in short order is beyond the capabilities of our species. Just one example to remind us of it: 56 years after Fidel Castro declared that the Cuban revolution is embarking on the road to socialism “A Dog Is Set on Fire in Manzanillo, Cuba” in early May.  What is worse, Cuba has no laws to prosecute those who set the dog on fire. Clearly, Cuban socialism is anthropocentric despite many advances in its “stewardship of nature.”  Despite 56 years of struggle for socialism, Cuba still has not yet joined the effort for an ecocentric ecological socialism.  

Time is the most scarce resource we face.  Global warming and catastrophic climate change may become self-sustaining within a couple of decades and if Wilson is correct the Sixth Extinction will become unstoppable by the end of the century—both are the existential threat to much of life on Earth, including our own species. But an ecocentrist will take solace in knowing that in the past five mass extinction events on average biodiversity returned after 10 million years. There is no reason to doubt that the same can happen again if Homo sapiens, the God Species, fail to act wisely in due time. The magic of life will go on until the sun burns out in about a billion year. 

Endnotes: 

1. Wilson defines it as “the amount of space required to meet all of the needs of an average person” in society.  “It comprises the land used for habitation, fresh water, food production and delivery, personal transportation, communication, governance, other public functions, medical support, burial, and entertainment.” (Wilson, 2016, p. 189)  For Rees and Wackernagel who originated the Ecological Footprint Analysis, it was a method “to estimate the resource consumption and waste assimilation requirements of a defined human population or economy in terms of a corresponding productive land area.” (Wackernagel and Rees, 1996,  p. 9).  Despite its popularity in the environmental studies fields and ecology movement, it suffers from definitional, theoretical, and methodological problems (se, e.g. Venetoulis and Talberth, 2008).”  
2. See, also, Plumb, 1964, p. 264; in relation to humanism, see, Abbognano, 1967, p. 70; in relation to science, see, Christian (2003, p. 350)
3. In this essay, I sometimes cite per capita income and sometimes discuss per capita consumption.  In reality, the two are slightly different measures because of savings.  But the difference is small in relative magnitude and for our purpose here unimportant. 
4. With some justification, one can characterize Wilson’s proposal to preserve biodiversity as ecomodernist (for ecomodernist statements see, An Ecomodernist Manifesto, 2015; Blomqvist, 2015; Shellenberger and Nordhaus, 2015; for their critique see, Angus, 2015; Trainer, 2016A, 2016B).  However, Wilson himself is most worried about the extreme versions of ecomodernist views propagated by those he calls Anthropocene enthusiasts (Wilson, 2016, pp. 47-52, pp. 71-82, pp. 95-100).  He summarizes their view as follows:  “Those who see the world through the lens of the Anthropocene enthusiasts work off an entirely different worldview from that of traditional conservationists. Extremists among them believe that what is left of nature should be treated as a commodity to justify saving it.  The surviving biodiversity is better judged by its service to humanity. Let history run its seemingly predetermined course. Above all, recognize that Earth’s destiny is to be humanized.” (ibid. p. 74).
5. There is also the “exotic meat” marketplace that in the United States includes alligator, alpaca, armadillo, bear, beaver, bobcat, caiman, crocodile, camel, coyote, capon, dove, frog, iguana, kudu, lion, llama, monkey, muskrat, opossum, otter, ostrich, pale, quail, turtle, venison and zebra meat. (see, for example, this online meat marketplace menu) 

Dedication: This essay is dedicated to Nuppy, my first cat friend and one of my most influential teachers. I lost Nuppy exactly nine years ago on the midnight of May 14, 2008.  He was fifteen and half years old. Aside from being an extraordinary cat, Nuppy taught me that cats are people too. Whenever I stand in the garden in awe in the presence of billions of other living beings surrounding me, I salute Nuppy who taught me that I am/we are only a tiny piece of a much greater existence.

References:

Abbagnano, Nicola. “Humanism,” in Edwards, Paul, ed. in chief, The Encyclopedia of Philosophy,Volume Three, pp. 69-72. 

An Ecomodernist Manifesto. 2015  

Angus, Ian. “Hijacking the Anthropocene,” Climate and Capitalism, May 2015. 

Barker, Graeme.  The Agricultural Revolution in Prehistory.  Oxford: Oxford University Press, 2006.

Baudrillard, J. (1987). Modernity. Canadian Journal of Political and Social Theory Revue Canadienne de Theorie Politique et SocialeXI(3), pp. 63-72. 

Blomqvist, Linus. “Nature Unbound, Decoupling for Conservation.” The Breakthrough Institute. September 2015. 

Boyden, S.  The Biology of Civilization: Understanding Human Culture as a Force in Nature, 2004. 

Catton, William, Jr. and Riley E. Dunlap. “A New Ecological Paradigm for Post-Exuberant Paradigm.”American Behavioral Scientist, 1980, pp. 15-47

Christian, David. Maps of Times: An Introduction to Big History,  2005.

Coates, John and Terry Leahy. “Ideology and Politics: Essential Factors in the Path toward Sustainability.”  Electronic Green Journal. 2006, pp. 1-22.  

Coren, Stanley. “How Many Dog Are There in the World?” Psychology Today. September 2012. 

Credit Suisse. The Global World Report 2016. 2016

Darwin, Charles. Variation of Animals and Plants under Domestication ( Volume 1, Volume 2). 1868. 

————————. The Descent of Man, and Selection in Relation to Sex. 1871/1981.  

De Vos JM, Joppa LN, Gittleman JL, Stephens PR, and SL Pimm. “Estimating the normal background rate of species extinction,” Conservation Biology, pp. 452-62, April, 2015.

Diamond, Jared. Guns, Germs, and Steel. 1997.

————————.  Collapse: How Societies Choose to Fail or Succeed.  2005. 

Driscoll, Carols. A. David W. Macdonald^, and Stephen J. O’Brien. “From Wild Animals to Domestic Pets; An Evolutionary View of Domestication.” Proceeding of the National Academy of Sciences of the United States of America, March 2011.

Foster, John Bellamy, Brett Clark and Richard York. “Capitalism and the Curse of Energy Efficiency: The Return of Jevons Paradox.” Monthly Review, November 2010.

Foster, John Bellemy, and Brett Clark. “The Planetary Emergency,” Monthly Review, December 2012.

Francione, Gary L. Animals as Persons: Essays on the abolition of Animal Exploitation. 2008. 

Gordan, Robert. “Does the ‘New Economy’ Measure Up to the Great Inventions of the Past?”  Journal of Economic Perspectives, Fall 2000. 

————————. The Rise and Fall of American Economic Growth. 2016. 

Heinrich Böll Foundation, Meat Atlas: Facts and Figures About Animals We Eat, January, 2014.

Kochhar, Rakes. “A Global Middle Class Is More Promise than Reality.” Pew Research Center. August 2015. 

Krugman, Paul. “Book Review: The Rise and Fall of American Economic Growth.” The New York Times, January 22, 2016. 

Levins, Richard. “Is Human Behavior Controlled by Genes? Review of Edward O. Wilson’s The Social Conquest of Earth.” August 2012.

Locey, Kenneth J. and Jay T. Lennon. “Scaling Laws Predict Global Microbial Diversity.” Proceeding of the National Academy of Sciences of the United States of America, Vol. 113, no. 21, May 24, 2016. 

Loss, Scott R., Tom Will, and Peter P. Marra. “The impact of free-ranging domestic cats on wildlife of the United States.” Nature. January 2013. 

Lynas, Mark. The God Species: Saving the Planet in the Age of Humans.  2011. 

Maddison, Angus. The World Economy: Volume 1: A Millennial Perspective, Volume 2: Historical Statistics, 2006. 

Naess, Arne.  Ecology, Community and Life Style.  Cambridge: Cambridge University Press, 1989. 

________.  "Spinoza and the Deep Ecology Movement," in A. Drengson and B. Devall (eds.), The Ecology of Wisdom: Writings by Arne Naess, Berkeley: Counterpoint, pp. 230-251, 2008. 

Nayeri, Kamran. “Economics, Socialism, and Ecology: A Critical Outline, Part 1,” Our Place in the World: A Journal of Ecosocialism. August 2013. 

————————. Economics, Socialism, and Ecology: A Critical Outline, Part 2,” Our Place in the World: A Journal of Ecosocialism. October 2013.

————————. “How Veganism Can Help Save the World.” Our Place in the World: A Journal of Ecosocialism. June 2014. 

————————. “On Bestiality (Zoophilia),” Our Place in the World: A journal of Ecosocialism. April 2015a.

————————. “An Ecological Socialist's Reflection on Edward O. Wilson's Sociobiology,” Our Place in the World: A Journal of Ecosocialism.  October 2015b.

Pedrós-Alió, Carlos, and Susanna Manrubia. "The Vast Unknown Microbial Biosphere." Proceedings of the National Academy of Sciences 113.24 (2016): 6585-6587.

PEW Research Center. “This capitalist drive for evermore wealth has a tendency to increase the “ecological footprint.”

Pollan, Michael. “The Intelligent Plant: Scientists Debate a New Way of Understanding Flora,” The New Yorker, December 2013. 

Plumb. J. H. The Pelican Book of the Renaissance. 1964. 

Rachels, James. Created from Animals: The Moral Implication of Darwinism. 1990. 

Rockström , Johan; Will Steffen, Kevin Noone, Åsa Persson, F. Stuart III Chapin , Eric Lambin , Timothy M. Lenton, Marten Scheffer, Carl Folke , Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes , Sander van der Leeuw, Henning Rodhe, Sverker Sörlin , Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark , Louise Karlberg, Robert W. Corell, Victoria J. Fabry , James Hansen, Brian Walker , Diana Liverman , Katherine Richardson, Paul Crutzen  and Jonathan Foley. “Planetary Boundaries: Exploring the Safe Operating Space for Humanity.” Ecology and Society, Vol. 14, Issue 2. 2009.

Roco, M.C. and W. S. Bainbridge. “Overview Converging Technologies for Improving Human Performance,” in Converging Technologies for Improving Human Performance.  2002. 

Shellenberger, Michael and Ted Norhaus. “Nature Unbound, A New Paradigm.” The Breakthrough Institute, October 2015.
Singer, Peter. Animal Liberation. 1975/2002. 

Sodhi, Navjot S., Barry W. Brook, and Corey JA Bradshaw. "Causes and consequences of species extinctions." The Princeton guide to ecology 1, 2009, pp. 514-520.

Steffen, Will. Wendy Broadgate, Lisa Deutch, Owen Gafffney, Cornelia Ludwig. "The trajectory of the Anthropocene: The Great Acceleration," Anthropocene Review, Januaray 16, 2015.

The Royal Society. People and the Planet Report. 2012. 

Trainer, Ted. “The Extreme Implausibility of Ecomodernism.” Our Place in the World: A Journal of Ecosocialism. March 2016A. 

——————. “On Decoupling of Economy and Nature: The Issues and Collective Evidence.” Our Place in the World: A Journal of Ecosocialism. July 2016B. 

Venetoulis, Jason ab=nd John Talberth. “Redefining the Ecological Footprint,” Environment, Development and Sustainability. August 2008, pp. 441-469. 

Vitousek, P., Ehrlich, A., and Matson, P.  “Human Appropriation of the Products of Photosynthesis,” BioScience, vol. 277, pp. 494-499, 1986. 

Wackernagel, Mathias and William Rees, Our Ecological Footprint. 1996.

Washington, Haydn. Human Dependence on Nature: How to Help Solve the Environmental Crisis. 2013. 

Wilson. Edward O. Creation: An Appeal to Save Life on Earth. 2006. 

—————————-. The Social Conquest of Earth. 2012.

—————————-. The Meaning of Human Existence. 2014.

—————————-. Half-Earth: Our Planet’s Fight for Life, 2016.

Wolf, Eric. Europe and the People without History. 1982. 

Wright, Ronald. A Short History of Progress. 2004.