Guest Blog by Sarah Gibbens: Here's What You Need to Know About Half-Earth Day

“Here’s What You Need to Know About Half-Earth Day”
By Sarah Gibbens
Originally published on October 23, 2017 by National Geographic

Scientists say saving the world’s species from mass extinction is possible, but it requires urgent action. Here’s how you can get involved.

Species are declining faster than ever, yet 86 percent of them may still be unknown. Studies say the extinction rate is now so high the Earth is entering its sixth mass extinction—but one group of scientists has a plan for how to keep it from getting worse.

Half the planet. That’s the amount of protected marine and land habitats some scientists say is needed to save 80 percent of the world’s species.

It’s one of environmentalists’ most ambitious conservation dreams. For a time, it remained little more than a theory. But now a group of prominent scientists have a plan for how to actually reach this goal, and they plan to unveil it Monday at an event called “Half Earth Day.”


Red-fan parrot, Deroptyus accipitrinus, Houston Zoo. Photograph from National Geographic.

Red-fan parrot, Deroptyus accipitrinus, Houston Zoo. Photograph from National Geographic.


The concept was first penned by famed biologist E.O. Wilson in his book Half-Earth: Our Planet’s Fight for Life. (Read more about the book here.) At 88 years old, Wilson has spent decades fighting for biodiversity (a term he also helped popularize).

Wilson credits an early edition of National Geographic magazine with inspiring him to save the ecosystems he says are now under a massive threat from human development and climate change.

So it’s fitting that the first time his foundation reveals its “Half-Earth” plans would be at the Washington headquarters of National Geographic, which is cohosting the event with the biologist’s E.O. Wilson Biodiversity Foundation.

On Monday afternoon, “Half Earth Day” will feature two large-scale events in which the public can participate.

The first is titled Conservation in Action and will discuss models of land and ocean conservation happening on large scales. The latter event will feature E.O. Wilson himself, musician Paul Simon, and author Sean B. Carroll, who plan to discuss practical steps that can be taken to conserve the environment on such a massive scale. More information on how to see a live stream of each discussion can be seen here.

At a session earlier in the day, scientists will attempt to map out how to set aside half the Earth for conservation

So what exactly are they trying to achieve?

In his book about the concept, Wilson explains that 80 to 90 percent of all species could be saved if half of the Earth’s habitats are set aside for wildlife.

“What we’re imagining is a spectrum of purely wild places,” said Paula Ehrlich, the CEO of the foundation. She referenced habitats as small as monarch gardens constructed in a person’s backyard to wildlife corridors that join two large protected habitats and allow species to move easily between the two.


Ring-tailed lemur, Lemur catta, Lincoln Children’s Zoo, Nebraska. Photograph from National Geographic.

Ring-tailed lemur, Lemur catta, Lincoln Children’s Zoo, Nebraska. Photograph from National Geographic.


Wilson’s concept is based off a theory he established in the 1960s with ecologist Robert MacArthur called island biogeography. The theory held that larger and more diverse habitats would give species a greater chance for survival.

Wilson’s foundation now plans to turn these theories into practical steps by outlining exactly where they think these protected habitats should be established. According to Ehrlich, they made these maps based on species range, distribution, and risk for human impact. She hopes that once people are aware of what needs to be protected, they’ll act.

The foundation also plans to lobby members of Congress to enact more protections for wild environments and species. Members of the public who feel motivated to contribute to the Half-Earth project in some way are asked to sign a pledge on the initiative’s website.

Sarah Gibbens is an associate digital producer at National Geographic.