Half-Earth: Our Planet’s Fight for Life

Book cover of Half-Earth Our Plant's Fight for Life by Edward O. Wilson.

Half-Earth: Our Planet’s Fight for Life proposes an achievable plan to save our imperiled biosphere: devote half the surface of the Earth to nature.

In order to stave off the mass extinction of species, including our own, we must move swiftly to preserve the biodiversity of our planet, says Edward O. Wilson in his most impassioned book to date. Half-Earth argues that the situation facing us is too large to be solved piecemeal and proposes a solution commensurate with the magnitude of the problem: dedicate fully half the surface of the Earth to nature.

If we are to undertake such an ambitious endeavor, we first must understand just what the biosphere is, why it’s essential to our survival, and the manifold threats now facing it. In doing so, Wilson describes how our species, in only a mere blink of geological time, became the architects and rulers of this epoch and outlines the consequences of this that will affect all of life, both ours and the natural world, far into the future.

Half-Earth provides an enormously moving and naturalistic portrait of just what is being lost when we clip “twigs and eventually whole branches of life’s family tree.” In elegiac prose, Wilson documents the many ongoing extinctions that are imminent, paying tribute to creatures great and small, not the least of them the two Sumatran rhinos whom he encounters in captivity. Uniquely, Half-Earth considers not only the large animals and star species of plants but also the millions of invertebrate animals and microorganisms that, despite being overlooked, form the foundations of Earth’s ecosystems.

In stinging language, he avers that the biosphere does not belong to us and addresses many fallacious notions such as the idea that ongoing extinctions can be balanced out by the introduction of alien species into new ecosystems or that extinct species might be brought back through cloning. This includes a critique of the “anthropocenists,” a fashionable collection of revisionist environmentalists who believe that the human species alone can be saved through engineering and technology.

Despite the Earth’s parlous condition, Wilson is no doomsayer, resigned to fatalism. Defying prevailing conventional wisdom, he suggests that we still have time to put aside half the Earth and identifies actual spots where Earth’s biodiversity can still be reclaimed. Suffused with a profound Darwinian understanding of our planet’s fragility, Half-Earth reverberates with an urgency like few other books, but it offers an attainable goal that we can strive for on behalf of all life.

Liveright / W.W. Norton (ISBN 978-1-63149-082-8)


The ongoing mass extinction of the natural world ranks with pandemics, world war, and climate change as among the greatest threats that humanity has imposed on itself. To lose so much of Earth’s biodiversity is to both destroy our living heritage, and to risk the stability of the planet, today and for all future generations.

“The crucial factor in the life and death of species is the amount of suitable habitat left to them.”—E.O. Wilson (1929 – 2021)

Our survival is inextricably entwined with the survival of all species that call our planet home. Yet our current destructive trajectory is resulting in mass extinction of species and irreparable damage to our world. With his Half-Earth call-to-action, E.O. Wilson has inspired a “moonshot” and created the groundwork for one of the grandest conservation efforts of our time, the Half-Earth Project.

Half-Earth is a call to protect half the land and sea in order to manage sufficient habitat to reverse the species extinction crisis and ensure the long-term health of our planet. The Half-Earth Project is bringing this goal to life.


Why one-half? The crucial factor in the life and death of species is the amount of suitable habitat left to them. As defined by the theory of island biogeography, a change in area of a habitat results in a change in the sustainable number of species by approximately the fourth root. As reserves grow in size, the diversity of life surviving within them also grows. As reserves are reduced in area, the diversity within them declines to a mathematically predictable degree swiftly – often immediately and, for a large fraction, forever.

When 90% of habitat is removed, the number of species that can persist sustainably will descend to about a half. Such is the actual condition of many of the most species-rich localities around the world. In these places, if 10% of the remaining natural habitat were then also removed, most or all of the surviving resident species would disappear.

If, on the other hand, we protect half the global surface, the fraction of species protected will be 85%, or more. At one-half and above, life on Earth enters the safe zone.


Half-Earth is a call to protect half the land and sea in order to manage sufficient habitat to safeguard the bulk of biodiversity. Advances in technology now allow us to comprehensively map the geospatial location and distribution of the species of our planet at high enough resolution to drive decision-making about where we have the best opportunity to protect the most species. This is the work of the Half-Earth Project.

Learn more about the science of the Half-Earth Project.

COP15 and the E.O. Wilson Biodiversity Foundation

The E.O. Wilson Biodiversity Foundation is an official observer at CBD COP15. The delegation is led by Paula Ehrlich, President & CEO, E.O. Wilson Biodiversity Foundation, and Co-founder, Half-Earth Project. For more information, email Joel R. Johnson, jjohnson@eowbfdev.wpengine.com


“A Biologist’s Manifesto for Preserving Life on Earth.” By E.O. Wilson, Sierra Club Magazine, January/February 2017.

“The Global Solution to Extinction.” By E.O. Wilson, Opinion, The New York Times, March 12, 2016.


“Could We Set Aside Half the Earth for Nature?” By Jeremy Hance. The Guardian. June 15, 2016.

“Half Earth: E.O. Wilson On How To Save The Planet.” Interview with E.O. Wilson. Radio Boston (WBUR). May 5, 2016.

“Half-Earth: Our Planet’s Fight for Life by Edward O Wilson – Review.” By Robin McKie. The Guardian. April 11, 2016.

“In ‘Half Earth,’ E.O. Wilson Calls for a Grand Retreat.” By Claudia Dreifus. New York Times. February 29, 2016.

“E.O. Wilson on Half-Earth, Donald Trump, and Hope.” By Jeremy Hance. Mongabay. January 17, 2017.

“The Year in Reading.” Contributors include Paul Simon. The New York Times Book Review. December 19, 2016.

“We Are All Noah Now.” By Thomas L. Friedman. The New York Times. September 7, 2016.

“E.O. Wilson Goes to Washington.” With Andrea Seabrook. NPR’s All Things Considered. May 22, 2016.

“Endangered Species: E.O. Wilson Visits Hill to Urge New Thinking on Conservation.” By Amanda Reilly. Environment & Energy Daily. May 19, 2016

“How to Save Life on Earth, According to E.O. Wilson.” By Jeffrey Brown. PBS Newshour. April 28, 2016.

“Why We Need a ‘Moon Shot’ to Catalogue the Earth’s Biodiversity.” By Quentin Wheeler. Huffington Post. April 22, 2016.

“Back to Nature.” By Christine J. Griffiths. Science. 351. March 17, 2016.

“Nature, All or Nothing” By Mary Ellen Hannibal. Huffington Post. March 16, 2016.

“‘Half-Earth: Our Planet’s Fight for Life,’ by Edward O. Wilson.” By Kate Galbraith. San Francisco Chronicle. March 10, 2016.

“Conservation: Glass Half Full.” By Stuart Pimm. Nature. March 10, 2016.

“A Wild Way to Save the Planet.” By Jedediah Purdy. New Republic. March 6, 2016.

“Nature’s Fair Share? Behind the Call to Hand Back Half of Earth.” By Fred Pearce. New Scientist. March 4, 2016.

“To Stave Off Extinction, Protect ‘Half-Earth.’” Science Friday. March 4, 2016.

“Has Human Influence Already Defined a New Epoch?” Science Friday.

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