E.O. Wilson, HALF-EARTH (2016)

E.O. Wilson, Half-Earth: Our Planet’s Fight for Life, Liveright, 2016, 259p

This is one of Wilson’s last four or five books, the first one following The Meaning of Human Existence in 2014. These books seem slighter that most earlier Wilson books, but this one has an especially striking theme: that to prevent mass extinctions, to preserve the Earth’s biodiversity that humanity’s survival depends on, we must save half the planet’s land-surface from human development. Keep it wild.

The idea sounds audacious but is not as implausible as it might sound, since large swaths of Earth’s land surface are unsuitable for human development anyway. He does not advocate splitting the planet down the middle, or any other such simplistic scheme. And in the six years since the book has been published, its ideas have gradually crept into the common currency of environmentalists and preservationists. E.g. here’s Kim Stanley Robinson in the Guardian: Empty half the Earth of its humans. It’s the only way to save the planet in 2018.

Key Points

  • Much of the book consists of Wilson setting the stage, with broad overviews of life on Earth, what naturalists do, tours of ecosystems, how much is known and how much more there is to know. The damage humanity has already done. How to think about humanity in the context of the planet’s history. The prospects for how smarter technology might allow humanity to thrive without further damaging the planet.
  • The central thesis comes 2/3 of the way through the book, via a lengthy list of specific “best places in the biosphere” worth preserving. It begins with, as it happens, “The Redwood Forests of California” (part of which is a few blocks from my home). The only others in the US are “The Longleaf Pine Savanna of the American South” and “the Madrean Pine-Oak Woodlands” of Mexico and the southwestern US. (Wilson doesn’t point this out, but most of the rest of the continental US has already been cut down, over the centuries, for agriculture and grazing.) More of the list in Ch. 15, below.
  • Wilson does use the expression “sixth extinction” and references Kolbert’s book in the notes at the end.
  • But (in Ch 9) he warns against the “Anthropocene ideology,” the idea to let nature take its course, that humanity will survive even if so many other species go extinct.



  • I’ve already quoted the book’s opening paragraph, What is man?, here.
  • Author regards this as last of a trilogy, following SOCIAL CONQUEST and MEANING OF HUMAN EXISTENCE, which he summarizes on page 2.
  • This book proposes that half the planet’s surface be preserved to save the life-forms that compose it, 3.1. “We would be wise to find our way as quickly as possible out of the fever swamp of dogmatic religious belief and inept philosophical thought through which we still wander.” 3.3.
  • Half-earth is a goal, not a process; psychologically a goal is better.

Part I, The Problem

1, The World Ends, Twice

  • 65mya the asteroid hit, ending the Mesozoic, beginning the Cenozoic, which in turn is divided into seven epochs, p8t. The Holocene began, affecting all three levels of life: ecosystems, species, and genes. Extinction events are rare; they occur at about 100my intervals. Many have suggested we are now in the Anthropocene.

2, Humanity Needs a Biosphere

  • The biosphere has upper and lower boundaries. It’s razor-thin compared to the bulk of the planet. Quotes Job, p12. We are fragile; he recalls the Rule of Threes (we can survive three minutes without air, etc) in survival training, p13. All species are weak and dependent, e.g. wolves and trees.
  • Habitats can suffer from alien species, ‘invasive’ p15. The evidence is against the idea that invasive species will settle down and become stable, p16.

3, How Much Biodiversity Survives Today?

  • Another name might be the Eremocene, the Age of Loneliness. Of estimated 2 million species, we know of 5500 mammals (only a few dozen left to discover), 10,000 of birds, 9000 of reptiles, 32000 of fishes, 6600 of amphibians, 270,000 of flowering plants.
  • But there is much left to discover. Estimates are we won’t be complete until the 23rd century.
  • What most people know, 26.7: a dozen or so common insects and that’s about it. “The millions of species that support the living world and ultimately our own survival have been reduced to ‘critters’ and ‘bugs.’ Within this black night of ignorance we have suffered a massive failure of education and media attention.”

4, An Elegy for the Rhinos

  • 27,000 remain. A century ago, millions. Hunted for their horns, for Chinese medicine.

5, Apocalypses Now

  • A fungus that kills frogs. The threat of invasive species. Birds on pacific isles, Hawaii. The dodo, in 1662. Other examples.

6, Are We As gods?

  • Is this collateral damage that we should accept (cf Stuart Brand); aren’t we ‘getting better’? Hollywood portrays a galaxy to colonize. What do we want? List of ideal, p48 (long and healthy life, status, dignity, etc.) – but these are also the goals of your family dog.
  • We think that “Our individual organismic selves, our tribe, our species, are the culmination of Earth’s achievement. Of course we think this way. So would members of any other species capable of self-reflection at the human level.” But while we’re wrecking the planet, we should reflect on our transcendental goals, those above self and tribe, p50, “They are fundamentally biological in origin….” But the lesson is we are not as gods….

7, Why Extinction is Accelerating

  • There are a few species that would not be missed, e.g. parasites.
  • HIPPO summarizes activities that destroy species:
    • Habitat destruction; invasive species; pollution; population growth; overhunting, p58.
  • We should reach 11 billion by end of the century.
  • Species that decline are not necessarily less vigorous; just bad luck.
  • Most species that went extinct gave rise to daughter species.

8, The Impact of Climate Change: Land, Sea, and Air

  • Experts advise not letting global temps to rise more than 2d C. The 2014 agreement.
  • But the tragedy of the commons prevails, with fishing in the open sea. Resultant damage to coral reefs.

9, The Most Dangerous Worldview

  • Some say don’t worry, we’ll adapt, that man will prevail, the wilderness will no longer exist. Even foreordained. The history of the human race… doubling of population. The idea of conservation began in 1872. Now there’s a new Anthropocene ideology, 74m, which says let things take their course: that the needs of people prevail. Erle Ellis, 75b. others believe extinct species can be brought back to life. But author thinks these people have least personal experience with the wildlands; “the most dangerous worldview is the worldview of those who have not viewed the world” p79.

Part II, The Real Living World

10, Conservation Science

  • Thus the “Anthropocene worldview” is a mistaken philosophy, due in part to a mistaken emphasis on ecosystems, as opposed to species and genes, 83m.
  • Example of WWF (the World Wildlife Fund), of which author was a part, how it expanded its scope. Example of Great Smoky Mtn NP, with tallies of species before and after certain policy changes, pp90-93.
  • There are no quick fixes; the precautionary principle is to proceed carefully—study, discuss, plan, p89b.

11, The Lord God Species

  • There are two kinds of scientists: those who go into science to make a living; or those who find a way to make a living so that they can go into science. Naturalists are in the second group. They gossip about discoveries. An unlimited number of discoveries remains. Example passages (Wilson usual poetic language, e.g. p97, “I’m paddling a canoe through the back channels of another coastal floodplain forest, this one surrounding the Choctawhatchee River…”). Holy grails are those missing links, dinosaurs that morph into birds, etc, 97.4. Or fantasies of discovering species thought extinct, e.g. something that would cause one to say, Lord God, what is that? Almost every naturalist has found at least one.

12, The Unknown Webs of Life

  • We need to understand how species relate to ecosystems. Many are not well understood. Examples discovered only in 2013, p103. Shortcomings of Anthropocene enthusiasts, p104. Examples of food webs, the binding ties of ecosystems, p104ff: vampire hunters; zombie masters; swindlers; slave makers; giant killers.

13, The Wholly Different Aqueous World

  • Most of the sea is still intact; take a journey. There are more phyla in the sand in the surf zone of a beach, than in a forest, p115t. “Meiofauna.” Out in the open water of the sea is the “pleuston”, the surface of the water where many organisms live, 115-6. Yet there are very few insects at sea.

14, The Invisible Empire

  • Namely, the human body, with hundreds of species of bacteria in just our mouths and esophagus’s. This is the ‘microbiome’.
  • Five kingdoms gave way to three domains, 123.6. Monera, Protista, Fungi, Plantae, and Animalia; now there are bacteria, archaea, and the Eukarya (including most of the original five).
  • The bottom of the ocean. What happens to a wooden boat that sinks into the sea.
  • Even if the end of the world, that layer of life would survive, and might go on to repopulate the surface, p130.

15, The Best Places in the Biosphere

  • The point of no return exists only for humanity. The Anthropocene worldview affects even The Nature Conservancy, p134. But there are millions of other species on the planet, that would survive our demise.
  • Author surveyed other naturalists and compiled a list of the ‘best places’ to preserve biodiversity.
  • List begins page 136: Beginning with the redwood forests of California. With others in the American south, the mountains of Mexico, Cuba and Hispaniola, the Amazon River basin, the Guiana shield, the table-top mountains (‘tepuis’) of Venezuela and western Guyana; a high region in Peru; the cloud and summit forests of Central America and the Northern Andes; the Paramos, high-grasslands of South America; the Atlantic forests of South America; the Cerrado, the savannah of east-central Brazil; the Pantanal, wetlands of Brazil and Bolivia; and the Galapagos. That’s just the Americas.
  • More in Europe and around the world, pp142-151.

16, History Redefined

  • History is not a prerogative of the human species. The average lifespan of a species can be tens of millions of years, or half a million years for mammals. The average is about a million years, after which a species changes enough to be called something different, or splits into two or more. Or vanishes, like 99% of past species. P157:

The human species, of course, has an evolutionary history, which reaches very far back in time beyond traditional recorded history. We, too, are the twig-end of a phylogeny. The multitudinous stories of human cultures are epics in the usual sense, but you will understand that the traits of human nature that have molded these stories are also products of evolution. … This is the reason that history makes no sense without prehistory, and prehistory makes no sense without biology.

  • Our key adaptation is our minds. We will keep exploring, because “exploration of the unknown is in our genes” p158.3. Our taxonomy. Examples. Now compiled electronically, in digital databases – 162m. Much is left to be done; but there is a shortage of experts.
  • There are two groups of biologists: one tribe believes that for every problem in biology there exists an organism ideal for its solution; the other tribe, the naturalists, believe that for every organism there exists a problem for the solution of which it is ideal, p165t.

Part III, The Solution

  • Summary p167: increase the area of inviolable natural reserves to half the surface of the Earth or greater.

17, The Awakening

  • Earth is a Goldilocks planet, but evolution stalled in Antarctica. We favor short-term decisions over long-range planning, a Darwinian propensity, p170.9. The world’s water crisis. Humans now use 38% of the planet’s productivity, 172.6. We gamble that we’ll figure something out, later.

18, Restoration

  • Most conservation projects require human intervention. Two examples, in which the author was personally involved…

19, Half-Earth: How to Save the Biosphere

  • All nations have some protected areas. Total, about 15% of the land area, and 2.8% of the ocean area. In order to halt the acceleration of species extinction, we need to aim for higher. “The extinction rate our behavior is now imposing on the rest of life, and seems destined to continue, is more correctly viewed as the equivalent of a Chicxulub-sized asteroid strike played out over several human generations.” 187.4

20, Threading the Bottleneck

  • It’s not about splitting the planet in half; the key involves ecological footprints. Is human overpopulation a threat? But that trend is declining. Estimate 10 billion by 2100, and a flip in reproductive strategy from r-selection (many poorly prepared offspring) to K-selection (fewer well-prepared offspring).
  • What about consumption? Technology will improve, 191. We will do virtual tours, stream videos. From extensive economic growth, to intensive economic growth, 192.9. A shift from quantity to quality. [[ These themes echo Pinker ]]
  • Hope to avoid climate change, perhaps via geoengineering. Artificial life and minds. 195. Hybridization, genetic modifications.

If people are to live long and healthy lives in the sustainable Eden of our dreams, and our minds are to break free and dwell in the far more interesting universe of reason triumphant over superstition, it will be through advances in biology. The goal is practicable because scientists, being scientists, live with one uncompromising mandate: Press discovery to the limit. Hand the baton from one to the next, if necessary, but never let the effort die.”

  • There will be whole brain emulation, WBE. Though people are afraid because Hollywood movies, 198b. (p199.3 mentions of 2001, Star Wars, The Terminator, I, Robot, Avatar, and Transcendence.) The brain evolved to survive, 202.8
  • The “bnr” industries – biology, nanotechnology, robotics will be the spearhead of the modern economy. Can reduce the need for travel. We will increasingly understand how the world works; “We will come awake.” 205.7

21, What Must Be Done

  • True altruism, the logic goes, is limited to family, tribe, race, nation p210, with extensions about patriotism and Olympic sports.
  • But a higher form exists, through group selection: “if altruism toward other members of the group contributes to the group’s success, the benefit the altruist’s bloodline and genes receive may exceed the loss in genes caused by the individual’s altruism” p210t.
  • Darwin quote. 211.8:

Despite all of our pretenses and fantasies, we always have been and will remain a biological species tied to this particular biological world. Millions of years of evolution are indelibly encoded in our genes. History without the wildlands is no history at all.

  • Last lines, p212:

We have come a very long way through the barbaric period in which we still live, and now I believe we’ve learned enough to adopt a transcendent moral precept concerning the rest of life. It is simple and easy to say: Do no further harm to the biosphere.

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