Protecting Earth’s Species

“…the only way to prevent this [ongoing extinction] is to permanently protect half of our planet for nature by the year 2050 – in other words, ‘Half Earth.’”

The details of land conservation are complicated, and not only the economics and politics but the biology itself (see the section “The Science of Half-Earth”). Although Wilson’s goal is admittedly wildly ambitious, Hiss learns that “it is not only doable but is already being done.” The people getting it done are as varied as people can be, but they have in common a love for Earth and an understanding that our planet is not only our home but, in a sense, our family. Humans are a special kind of animal with an inborn empathy for other forms of life; Hiss and the people he portrays feel this acutely. This is a book especially for readers who share this intuition.

Such a sensibility is often attributed to indigenous people, and much of Rescuing the Earth is about indigenous people in Canada, the US, and Australia. Their stories are real-life, factual accounts of what indigenous people are accomplishing today by combining hard work, modern biology, and a reverence for tradition. In the words of Valerie Courtois, director of the Indigenous Leadership Initiative in Canada, “In the planning that gets taught in schools, first you mark off areas for industrial development, then you decide what to protect. But in the planning that gets taught by the land, we start out asking, ‘what needs to stay where it is for indigenous people to stay who they are.’”

“Although Wilson’s goal is admittedly wildly ambitious, Hiss learns that ‘it is not only doable but is already being done.’”

The history of indigenous people is a history of dispossession, but the “Half-Earth” vision does not mean that anyone has to move – quite the opposite. Canada and Australia in particular have returned large amounts of land to previously displaced native populations. Detailed studies have shown that lands managed by indigenous people in these programs have the same biodiversity as nearby areas protected by the government. So the fact that indigenous people live on (and potentially control) 25% of the world’s land offers significant first steps toward half-earth goals. This approach is essential in developed countries to reverse the pattern of famine and poverty that forces indigenous people into desperate actions that despoil their own land.

As the climate changes, plants and animals need unobstructed paths to migrate and adapt. With the warming climate, north-south corridors and passages to higher elevations will be needed to allow movement to cooler places. In many places, such as the American West, east-west pathways are needed to allow migration away from areas that will fall into permanent drought. But parks and wilderness preserves have been set aside in a disconnected, ad hoc way, often without careful thought given for the lifecycles of the local species. So part of Half-Earth is connecting the already preserved spaces.

“…studies have shown that lands managed by indigenous people in these programs have the same biodiversity as nearby areas protected by the government.”

There are a great many places in the developed world where natural spaces can be connected to create corridors for wildlife. Hiss tells of how in the U.S., a handful of enthusiasts are restoring the vast pine forests in the southeast, while others are creating a major expansion of the Appalachian Trail. In the west, people are forming a connecting link along the length of the Rockies into Canada. Each of these protected spaces were originally created through the efforts of just a few people, or even a single individual, motivated not to “save the Earth,” but by a personal connection with their own small part of it.

These small changes can add up to big benefits. Wildlife highways are often within sight and sound of actual human highways. The Trans-Canada Highway incorporates simple overpasses and tunnels for animals, paths that are camouflaged and off-limits to humans. Thirty thousand cars a day drive a stretch near Banff, but according to ecologist Tony Clevenger, “… for the animals it’s as if the cars aren’t even there.” Similarly, the Delmarva Oasis Plan to save the Atlantic Ocean and Delaware Bay shorelines where Virginia, Delaware and Maryland come together demonstrates how enlightened planning can create space for wildlife even right next to high-density urban areas .

Even today large tracts of the natural world remain untouched by humans. The great forested areas, Siberia, the Amazon, and the boreal forests of North American comprise most of the world’s remaining wilderness. While development threatens Siberia and the Amazon and is largely unchecked there, the North American Boreal is still mostly virginal. These intact preserves illuminate what a nation needs to succeed in protecting its natural heritage: unprotected land still available for protection, a tradition of conservation, the ability to afford to leave wild space undeveloped, and the practice of operating by rule of law.

“To save nature and to save ourselves, we must reconnect nature to people’s daily life.”

So it is up to nations like Canada, Australia, and the United States to lead the way. At present the US has protected about 15% of its land and 12% of its marine areas. This amounts to 10% of the world’s protected land by a country covering 6% of the world’s surface. But it is not enough. Some smaller industrial countries already have higher percentage – Germans for example have placed about 50% of their land in protected status, but they have little left to protect. The Biden administration has announced that it intends to double the protected area in the US in this decade, a “30 by ‘30” program that marks an important milestone on the way to Half-Earth.

To save nature and to save ourselves, we must reconnect nature to people’s daily life. People have an innate attraction to other species. Some of the first words that children learn are the names of animals that most will never see. Everywhere – in the wild, near farms, around urban centers, and near small towns – the job is the same. Set aside what is still whole, repair what we can, reconnect pieces that have been cut apart. As Hiss concludes, “. . . we’re able to construct a new ability, a human protection pattern that can safeguard the biosphere and its species.” Including our own.

The Science of Half-Earth

It was the work of biologist Edward Wilson that inspired Tony Hiss, and it is important to understand the science behind Wilson’s seemingly audacious goal of protecting half of earth’s land and sea for nature by the year 2050.

Biologists have found that as the area of a habitat is reduced, the percentage of species that can survive in what remains is also reduced—but surviving species will decrease more and more rapidly as the area shrinks.

If the area of a habitat is reduced by half, the fraction of species that can survive in what remains is about 85% of the original number of species that were found there. Note that this fraction is for the number of species, not the number of individual plants and animals within a species. In other words, a much greater percentage of individuals will be lost, likely even the majority of them, but about 85% of species will have enough individuals left to be able to avoid extinction. So holding habitat reduction to 50% is the goal of the Half-Earth Project.

The Half-Earth projection is not exact; it is an estimate. The actual area needing protection depends on the species and the details of their range. For example, some species may only need 30% of their original range to survive, while others may need 70%. But even saving a very large area may not be enough if, for example, it’s divided by a highway that keeps species from reaching their breeding grounds or from making their seasonal migrations. Protected spaces must be carefully designed according to the overall ecology of the area.

It would be a disaster to lose 15% of the Earth’s species and many more of its individuals, but we are on our way to something much worse. The Half-Earth Project acknowledges that a high level of extinction is already inevitable. But by identifying and protecting critical habitats, we can prevent an even more calamitous mass extinction. Right now plants and animals are going extinct at a rate hundreds, or even thousands, of times faster than they would if not for the impact of humans on their environments. And the full shock of climate change is yet to be felt.

The impending extinction has many drivers – overhunting and overfishing, pollution, and more – but the primary cause is habitat destruction. It is surprising that when 90% of a habitat is lost, more than half of the species can still survive. But note from the chart that at that point the species survival plunges into the sharp downward slope of the curve. The cliff quickly becomes so steep that all remaining species may completely die out. Many of the world’s regions with the greatest biodiversity are at exactly this point.

Madagascar, one of the world’s richest and most irreplaceable natural areas, has lost 90% of its forests to “slash and burn” agriculture. It is one of a handful of areas of that have been identified as a “hotspot” (see the section “Where Life is Hot”) — an environment with unusually great biodiversity that has lost most of its habitat and is under threat to lose even more. Such a biologically rich area is well suited to farming, hunting and fishing, and forestry. It is possible to for these activities to be done sustainably, but they cannot be permitted in any hotspot. These areas have already lost too much. They are the places that most need protection.

We have an even more urgent reason for preservation in the face of global warming. These natural areas are especially good at absorbing the excess carbon that‘s heating our planet, locking it away in great quantities in soil and deep waters. It is estimated that the earth’s soil contains far more carbon than all the planet’s atmosphere and plant life combined. Since the 1850’s, when the Industrial Revolution began the current period of global warming, the soil, forests and oceans have captured more than half of the extra carbon that humans released into the air.

In this way the planet has so far shielded us from the full effects of global warming. At some point — and perhaps very soon — these carbon-storing natural areas will be saturated, and the process may even be reversed, the stored carbon being released back into the air in enormous quantities. To protect ourselves from the worst effects of global warming, we must ensure that the large areas of land and sea that have so far been spared exploitation, like the boreal forests of Canada, are protected and preserved.

Where Life Is Hot

Just a few dozen small places on earth contain an enormous percentage of plant and animal species, many of which are found nowhere else. But these habitats are under severe threat. Protecting the planet from a catastrophic extinction crisis must necessarily begin with protecting these environmental “hotspots.”

Imagine being deep within a jungle in Ecuador, where the Amazon meets the Andes. Your campsite is in the middle of nowhere. Animals show up that might never be seen again. It’s all unexpected. You may hear jaguars, or dolphins jumping along in the river. Peering into the jungle, you just see endless green.

Comprising just 2.5% of the world’s land surface, these few dozen hotspots are home to 44% of all the world’s plants and 35% of all mammal, bird, reptile, and amphibian species.

You’re in the Yasuni Preserve, one of the most biodiverse places on the planet, with some 596 species of birds, 260 species of amphibians and reptiles, and where over 1,000 species of trees, shrubs and vines thrive.

Unfortunately, Yasuni also sits atop rich oil reserves, which is just one reason why this uniquely fertile habitat has already lost over 70% of its original area to human encroachment. Biologists call such biodiverse but severely threatened areas “hotspots.” Comprising just 2.5% of the world’s land surface, these few dozen hotspots are home to 44% of all the world’s plants and 35% of all mammal, bird, reptile, and amphibian species, many of which are found nowhere else on the planet.

In the race to prevent the next mass extinction, hotspots are the places we need to save first.

Fewer than 40 hotspots have been identified on land, most in humid tropical forests, and a smaller number have been designated in the oceans where research is greatly lagging. The loss of the remaining area of any one of these critical spaces would be disastrous, but even among these select few places, several, like the Yasuni Preserve, stand out as especially critical.

There are as many different insect species in just a couple of acres of the preserve as in all of North America.

Hotspots with the greatest number of species at risk include the Amazon, Philippines, Madagascar, Malaysia, Borneo, the eastern Himalaya, the Western Ghats in India, Sri Lanka and coral reefs. According to some biologists, the Cape Floral Kingdom in South Africa may be the world’s “hottest hotspot” because of the threats it is facing. A closer look at both the Yasuni Preserve and the Great Barrier Reef in coastal Australia illustrate what is at risk in all these hotspots and why.

Life on the Yasuni Preserve is so rich that it is hard for people raised in an industrialized society to even imagine. There are as many different insect species in just a couple of acres of the preserve as in all of North America. Covering only about one-tenth of one percent of the Amazon, Yasuni is home to one-third of all the Amazon’s species of birds. It is also home to several indigenous peoples, including the Tagaeri and the Taromenane, two tribes listed as “uncontacted” although some have been murdered by poachers.

The Yasuni Preserve’s rich oil reserves pose a grave threat, despite national and international recognition of the area’s ecological significance. Protection of Indigenous land from development is written into Ecuador’s constitution, with the exception of extracting oil. So far the government of Ecuador, even during successive administrations, has resisted both domestic and international campaigns to keep the preserve off-limits to exploitation. After initially agreeing to fully protect the Yasuni (and even collecting millions of dollars from foreign governments and philanthropists to do so), the land has been opened to road construction and drilling.

While the Yasuni might possibly have the greatest density of unique species on the Earth’s surface, neither it nor other species-rich land preserves can claim the distinction of the greatest concentrations of animal biodiversity. That distinction belongs to the coral reefs of the warm seas. People aren’t nearly as familiar with marine life as with life on the land. For example most of us could readily name ten kinds of birds, but for many people all fish are pretty much the same. It is probably surprising to learn that there are perhaps a thousand different species of coral. And as it happens, a great many of these species will be among the first victims of the ongoing extinction crisis.

The Great Barrier Reef is the world’s largest, comprising thousands of individual coral reefs. It is a critical habitat for many endangered species. But it is now facing destruction from the direct and indirect effects of greenhouse gases. Warming seas have bred a super abundance of predators that are destroying the reefs. And as the seawater absorbs more carbon from the atmosphere, it becomes more acidic, inhibiting shell formation. These and other related factors such as the massively increasing amounts of sunscreen we use have triggered frequent and massive die-offs of large sections of the reef, and equally worrying, have prevented the coral from re-growing.

It’s easier to relate to “save the Galapagos” or to “save the redwoods” or to save a town’s open space than it is to save an abstract percentage of a land area, even though the outcomes are the same.

Like the Yasuni Preserve, the Great Barrier Reef is protected, but only after a fashion. The 2050 Plan for the Reef by the Australian government addresses threats that have caused some of the great die-offs. The plan aims to improve water quality, reduce the over-abundance of predatory starfish, and restore damaged areas. But, like Ecuador’s plan for the Yasuni, the Australian government plan has done nothing to mitigate the primary threat, which for the reef is climate change. Australia lags only the United States in resisting meaningful action in response to the changing climate. But in 2022, following a series of apocalyptic wildfires, climate change became a top issue for Australian voters, leading to a change in government.

The Yasuni and the Great Barrier Reef illustrate an important truth: peoples’ willingness to protect nature is rooted in the familiar. Half-Earth aims to harness this tendency by restoring nature’s rightful place in our everyday lives, where its timeless value is undeniable. Protecting nature that’s “just outside the back door” focuses people on a viable goal with personal value. It’s easier to save a town’s open space than it is to save an abstract percentage of land area.

Yet the results can turn out the same. Many of the protected areas in the world were saved in just this way, through local action. But today it’s clear just how much life all around the planet is connected. Even the most remote regions like the Great Barrier Reef and the Yasuni are not safe from the changing climate or other global threats. Billions of animals died in the wildfires in overheated Australia, whether or not they were in preserves.

Our awareness of nature “just outside the back door” must expand. The primary, immediate, and vital need to save the Earth’s hotspots will not alone prevent the impending mass extinction. It is only part of the Half-Earth mission. The good news is that a surprising amount, a sufficient amount, of the natural world is still out there, waiting to be saved.

Greta