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.

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.

“Unless humanity learns a great deal more about global biodiversity and moves quickly to protect it, we will soon lose most of the species composing life on Earth.” – E.O. Wilson

Why Half?

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.


Which Half?

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.

E.O. Wilson

Edward O. Wilson is currently Honorary Curator in Entomology and University Research Professor Emeritus at Harvard University, Chairman of the E.O. Wilson Biodiversity Foundation Board of Advisors, and Chairman of the Half-Earth Council. He is generally recognized as one of the leading scientists in the world. He is also recognized as one of the foremost naturalists in both science and literature, as well as a synthesizer in works stretching from pure biology across to the social sciences and humanities.

More about E.O. Wilson
Publications and awards (updated 9/2020)
In the news

Half-Earth: Our Planet's Fight for Life by E.O. Wilson


So how do we do this?
How do we make caring for the rest of life part of our common humanity and the way we live our lives?

The Half-Earth Project brings together deep scientific research, experienced leadership and inspirational engagement as never collaboratively convened before, creating fresh goal-driven energy where existing efforts are losing ground. It addresses gaps in our current approach to our shared species extinction crisis and all of the cascading effects, and creates a compelling campaign for re-invigorated action.


The Half-Earth Project is championing research to better understand our world, support conservation efforts, nurture future biodiversity stewardship, and perpetuate conservation efforts worldwide. We are working continuously to discover and identify our planet’s species and support regional biodiversity research and scholarship.


The Half-Earth Map is providing leadership to inform the identification of which places we can best manage for conservation in order to protect the most species. The Knowledge Platform is fostering greater understanding and action about how we can get to Half-Earth. Model conservation efforts are also showcased to inspire and inform best practices to get to Half-Earth.


The Half-Earth Project is engaging people everywhere to join us and participate broadly to achieve the goal of Half-Earth. We are tracking progress towards the goal of Half-Earth as an inspiring moonshot we can all work together to reach.

Half-Earth Project Team

Motivated by the species we are working to protect and the health of our shared planet, the Half-Earth Project team is a gathering of expertise from around the world necessary to achieving this grand goal.

Our Team
Our Half-Earth Council
Our Supporters

The Half-Earth Council

The Half-Earth Council is composed of thought-leaders across the wide-ranging fields of expertise necessary to comprehensively address the extinction crisis and support a movement culture that works to protect half the Earth for the rest of life. The Half-Earth Council has scientific leadership at its core. Members of the Council include population, sustainability and restoration specialists; public and private conservation leaders; indigenous peoples advocates; biodiversity-minded economists; business engagement experts, creative media producers and celebrity icons.

    E.O. Wilson
    Half-Earth Chairs
    Greg Carr

    Gorongosa Restoration Project

    Kris Tompkins

    Tompkins Conservation

    Sean B. Carroll

    Howard Hughes Medical Institute,
    University of Wisconsin

    Laura Turner Seydel

    Turner Foundation, Captain Planet

    Jeff Sachs

    UN SDSN, Earth Institute
    Center for Sustainable Development at Columbia University

    Mathis Wackernagel

    Global Footprint Network

    John Seager

    Population Connection

    Robin Kimmerer

    SUNY College of Environmental Science and Forestry

    Mike Phillips

    Turner Endangered Species Fund

    Louie Psihoyos

    Oceanic Preservation Society

    Tom Lovejoy

    UN Foundation, George Mason

    Sylvia Earle

    Mission Blue

    Dawn Wright

    Chief Scientist, Esri

Donors and Supporters


11th Hour Project
Brad & Shelli Stanback Donor Advised Fund
Burt’s Bees Greater Good Foundation
Environmental Systems Research Institute, Inc. (Esri)
ESF College Foundation
Ettinger Foundation
Falconwood Foundation, Inc.
Fidelity Charitable Gift Fund
Fred Stanback Donor Advised Fund of Foundation for the Carolinas
Gordon & Betty Moore Foundation
Greg C. Carr Foundation
HW Fund at The San Diego Foundation
James M. & Cathleen D. Stone Foundation, Inc., a Donor Advised Fund of the Boston Foundation
Libra Foundation
Life Technologies Foundation
Mariposa Fund
Nathan M. Ohrbach Foundation
National Geographic
National Science Foundation
Park Foundation
San Francisco Foundation
Silicon Valley Community Foundation
Sulentic Family Foundation
Schwab Charitable
Turner Foundation
University of North Carolina at Chapel Hill
Charitable Gift Trust
Wildlands Network
W.W. Norton
Zanina Fund of the Jewish Community Foundation


Dr. Elizabeth Albright
Marcia Angle & Mark Trustin
William F. Allen
John W. Anderson, III
Jonathan Arnold
T.A Barron
Ed Bass
Gregory C. Carr
James Cashel & Anne Ching
Jack & Laura Dangermond
Thomas and Sara de Swardt
Sarah Bess Dworin
Gerry Ehrlich
Harrison Ford
Neal Fowler
Steve Remmer Fox
Valerie Gates
Ivan Gayler
Jeremy Grantham
Anthony Hobart
Kanya Honoki
Tom Johnson
Thomas Kaplan
Victoria Keziah
Courtney Lorenz
Jane Marcus
Mark Moser
Gordon & Courtney Nichols
Bill & Donna Patterson
Tom & Kristi Patterson
David Prend
Robert Rowe
Roger Sant
Aaron Santell
Paul Simon
Richard Slawson
Karen Slovin
Charles Smith
Natalie Soonthornswad
Gary Staab
Fred Stanback
Tom Steyer & Kat Taylor
Brad & Shelli Stanback
Ashley Gordon Stone
James Stone
Mark Tercek
Jeff & Laurie Ubben
Bill Veghte
Craig Venter
Dr. David Welborn & Ann Hunter-Welborn
Quentin Wheeler
Edward & Irene Wilson
Paul Wintner
Robert & Blaikie Worth