Photo : Getty

Humanity has pushed Earth to the brink with more than a million species threatened with extinction. There are a number of ideas for how to stop the collapse of nature, but among the most radical is the idea of conserving half the planet.


Conservation means protecting land and the ocean, of which there are many approaches. But the general gist is to set aside half of all the planet so nature can thrive free from human interference. According to a United Nations report issued last month, 15 percent of Earth’s land is currently protected along with 7.8 percent of the oceans.

The concept of cordoning off 50 percent of the planet , perhaps not shockingly known as Half Earth, has been around for decades, but it has gained steam in recent years thanks in part to a book by legendary biologist E.O. Wilson and endorsement earlier this year by members of the United Nations Convention on Biological Diversity. But a new paper finds that taking a Half Earth approach could substantially impact a billion people. The biggest portion of people impacted come from low and low-middle income countries, underscoring the need for a just conservation strategy that doesn’t screw the poor.


Nature has faced a withering decline in recent years in the face of urban expansion, deforestation, the climate crisis, and a host of other human activities. That decline comes with real risks to humans since we rely on nature for everything from flood protection to fisheries and livelihoods. If it disappears, we wouldn’t be far behind.

Wilson and other researchers have settled on a Half Earth approach to conservation by arguing that it provides equilibrium for most species on Earth. Their modeling suggests conserving half the planet will protect up to 85 percent of species. Degrade 90 percent of the planet and only 50 percent of species would make it through.

Avoiding that outcome (or worse) would seem to be in humanity’s best interest. But for all the talk about helping nature, the actual human toll—which includes good and bad outcomes—of doing so has been largely absent from the conversation around Half Earth .


“We noticed that the Half Earth proposal was gaining increasing traction among conservationists and policy makers, but that the debate was remarkably silent on the potentially very large social implications of such a proposal,” Chris Sandbrook, one of the authors of the new study and geographer at the University of Cambridge, told Earther.

The new findings in Nature Sustainability are a way to start shining a light on those implications. The researchers looked at 846 ecoregions (areas with similar ecosystems) of the world and considered two approaches. The first called for conserving half of all of them while the other looked at conserving half where it was feasible. In the second case, “feasible” meant areas where there was half an ecoregion that could still be conserved or restored. That automatically cut down some options like the eastern U.S. or most of the Indian subcontinent because humans have already altered so much of the landscape. But in all cases, the analysis looked to minimize the number of people impacted by conserving half the Earth.


T he findings show that a billion people could be impacted in the conservation free- for- all scenario. That number falls to “just” 170 million in the feasible conservation scenario. But in both cases, countries classified by the World Bank as lower-middle income disproportionately bear the burden.

In the first conservation scenario, a whopping 53 percent of the people impacted live in lower-middle income countries like India, Egypt, Indonesia, and the Philippines. Upper-middle income countries like China also bear a heavy human burden in both scenarios (and, in fact, they bear basically the same burden in the feasible conservation scenario as lower-middle income countries).


It is , of course, possible that some of the “burdens” turn out to be good. Nature is associated with mental well-being, though the exact connections are still being teased out. There are also the aforementioned benefits like offering flood protection from storm surge and soil conservation that are very real. But conservation also has a history of dispossessing indigenous groups from their land— land that they often manage as effectively or better than their Western conservationist counterparts.

“We need to address the environmental crises in an environmentally and socially just way, both for the ethical implications and for increasing the likelihood that these conservation measures succeed in tackling the environmental issues,” Sandbrook said.


Any effective global conservation strategy will have to take these realities into account. Otherwise, they’ll contribute to the same problems that have been screwing people and ensure the 21st century is just as crappy and unjust as the ones that preceded it.