Fifty-Fifty

A biologist’s manifesto for preserving life on Earth

- E. O. Wilson

1 We are playing a global endgame. Humanity’s grasp on the planet is not strong; it is growing weaker. Freshwater is growing short; the atmosphere and the seas are increasingly polluted as a result of what has transpired on the land. The climate is changing in ways unfavourable to life, except for microbes, jellyfish, and fungi. For many species, these changes are already fatal.

Because the problems created by humanity are global and progressive, because the prospect of a point of no return is fast approaching, the problems can’t be solved piecemeal. There is just so much water left for fracking, so much rainforest cover available for soybeans and oil palms, so much room left in the atmosphere to store excess carbon. The impact on the rest of the biosphere is everywhere negative, the environment becoming unstable and less pleasant, our long term future less certain.

Only by committing half of the planet’s surface to nature can we hope to save the immensity of life-forms that compose it. 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. The Half-Earth proposal offers a first, emergency solution commensurate with the magnitude of the problem: By setting aside half the planet in reserve, we can save the living part of the environment and achieve the â€‹quarter or one-third? Because large plots, whether they already stand or can be created from corridors connecting smaller plots, harbour many more ecosystems and the species composing them at a sustainable level. 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.