The 30 Percent Goal: Is Bigger Always Better for Biodiversity?

Original publication by Fred Pearce for e360.yale.edu on 7 December 2022

A school of yellowtail in Mexico’s Cabo Pulmo National Park, a small protected area rich in marine life. 
OCTAVIO ABURTO-OROPREZA / ILCP / TRIBUNE NEWS SERVICE VIA GETTY IMAGES

The UN biodiversity conference now meeting in Montreal is considering a proposal to commit to putting 30 percent of land and sea under protection by 2030. Some ecologists warn that focusing too much on the size of protected areas risks missing what most needs saving.

In 2009, the U.S. government turned more than 190,000 square miles of pristine ocean centered on the Mariana Trench in the remote Pacific into one of the world’s largest protected areas. The same year, Mexico completed a management plan for the Cabo Pulmo coral reef in the Gulf of California, covering just 27 square miles.

Which action achieved the most? As the biggest United Nations conference on biodiversity in a decade gathers in Montreal this week, it is a crucial question.

The conference has big plans to protect biodiversity by more than doubling the area of the planet under protection to 30 percent of both land and ocean by 2030. By going big, the Mariana Trench protected area is a model of what is planned. But many ecologists say that by throwing a protective arm around an ecosystem under no current threat, it accomplishes little. Whereas Mexico’s tiny Cabo Pulmo National Park, though only slightly more than one ten-thousandth the size, has done much more, bringing marine life back to a coral reef once lauded by French marine explorer Jacques Cousteau as “the world’s aquarium,” but then ravaged by fishing.

Size maybe isn’t everything.

As well as pledging to put 30 percent of land and sea under protection, the draft text of the Global Biodiversity Framework being discussed at the Montreal Conference of the Parties to the UN’s Convention on Biological Diversity (COP15) also calls for 20 percent of damaged ecosystems to be “under restoration,” reducing alien species invasions by 50 percent, and establishing a funding stream of $200 billion per year to do it all.

New protected areas should be chosen not for their size, one biologist says, but for their ecological value.

Such bold and measurable targets are aimed at giving international biodiversity commitments the same high profile as those on climate.

Many ecologists applaud the ambition and would like even more. The American biologist Edward (E.O.) Wilson, who died a year ago this month, famously called for half the world to be set aside for nature. In June this year, a major international assessment, headed by James Allan, an ecologist at the University of Amsterdam, reckoned that 44 percent of the land surface needs “conservation attention” in order to prevent “major biodiversity losses.”

Another study, published the same month, estimated that currently protected areas, even if properly policed, were insufficient to protect about half of the non-flying land mammals analyzed. “Hundreds of mammal species appear to have no viable protected populations,” says lead author David Williams of the University of Leeds. They include some animals not formally recognized as threatened, including the white rhinoceros.

But while more protected areas are needed, some ecologists warn that a fixation on maximizing their size to achieve the 30-percent target is the wrong approach. They fear perverse consequences, including wasted money, missing out on what most needs protecting, and causing counterproductive conflicts with Indigenous and local communities.

Any expanded network of protected areas should be “based on biodiversity rather than total area,” says Williams. “The worry is that one big target like 30 percent subsumes different objectives.”

Key biodiversity areas that fall outside protected lands
PROTECTED PLANET

The first draft of the framework included targets for protecting specific ecosystems and quantified objectives for species and genetic diversity, says Sandra Diaz of the National University of Córdoba Argentina, who was involved in advising the process. But these precise objectives have been replaced by “vague aims,” she complained in Nature last month. “Formally protecting a proportion of the planet’s most pristine ecosystems will by itself fall far short,” she warned.

There is history to this. Too many protected areas have already been created that do little more than replicate existing biodiversity protection, says Christian Hof, an ecologist at the Technical University of Munich. “The uncoordinated expansion of protected areas can result in wasted resources, if care is not taken to protect as many species communities and environmental conditions as possible.”

New protected areas should be chosen not for their size, he says, but for their ecological value. That value may derive from the number of species a protected area contains or the uniqueness of the collections of species found in it. Further value may come from maintaining and enhancing connections between biodiversity hotspots — so that animals can make their seasonal migrations or retain areas for hunting, and natural processes such as river flows can function properly.

“Lots of Greenland is protected, but isn’t threatened, so what is that protection actually doing?” asks a scientist.

Williams says that existing protected areas are often “too poorly connected to provide robust and resilient protection” for the species they contain. This summer, a team headed by Robin Naidoo, lead scientist at WWF-US, quantified that concern. It mapped globally important areas for current animal movements and found that two-thirds of them are unprotected. Moreover, about a quarter are in natural landscapes suitable for agricultural expansion.

Such wildlife corridors often have an importance out of all proportion to their size, meaning they may be sidelined by governments pushing to meet percentage protection targets. And that importance will likely increase. “Connectivity among protected areas will become even more important when species that are currently under protection shift their ranges to track changing climatic conditions,” says Hof.

While the draft framework mentions the importance of connectivity, there is no target or “headline indicator” to require and track progress in achieving it, says Naidoo. This is despite a recommendation for such an indicator from an expert workshop convened in April by the UN Environment Programme and others and attended by scientists from more than 100 countries.

The Stolby Nature Reserve in eastern Russia.
ALEXANDER MANZYUK / ANADOLU AGENCY VIA GETTY IMAGES

Other neglected forms of connectivity that need protecting to maintain biodiversity include places that are hard to fence off for protection, such as the world’s diminishing number of wild, undammed rivers and border zones between ecosystems, such as coastlines. Lacking protection, “intact coastal regions are now rare,” says Brooke Williams of the University of Queensland. Most are in just three countries with Arctic shores: Canada, Russia, and Greenland. The draft framework being discussed in Montreal calls for better “connectivity” between land and sea protection but lacks a target for addressing it.


Many ecologists voice concern that the push to maximize areas being protected could incentivize protecting ecosystems that are largely intact and under low threat of disturbance. Such protection is easy to achieve at scale, because there are few competing commercial demands on the land. But it may not deliver much for nature. This lure is already creating a distortion of conservation priorities. “Lots of Greenland is protected but isn’t threatened, so what is that protection actually doing?” asks Williams.

Piero Visconti, an ecologist at the International Institute for Applied Systems Analysis (IIASA) in Laxenburg, Austria, cites U.S. “protection” of remote wilderness in Alaska and Australia’s extensive designation of protected areas in its remote arid interior. Recent additions there have resulted in 50 percent of the land area of Australia now being “protected.” While that puts the country well ahead of the proposed 2030 international target, it still leaves arguably the country’s greatest biodiversity treasure, the Great Barrier Reef, at dire risk from pollution, shipping, and other threats. In November, a UNESCO team said the reef should be added to the list of World Heritage Sites “in danger.”

There is growing concern about whether top-down protection by governments is the best way to address biodiversity issues.

Similar questions have been raised about the recent rush by the United States, Britain, France, and other governments to declare as protected areas vast expanses of remote and pristine ocean, such as the Mariana Trench region. Luiz Rocha at the California Academy of Sciences has noted that such initiatives “protect areas that nobody uses [but] invariably exclude the only areas that would benefit from spatial protection, those close to the shore.” A 2018 study found that the U.S. has fully protected only about 1 percent of the waters around its continental shores, but 43 percent of remote waters under its control, mostly in the Pacific Ocean.

In theory the Global Biodiversity Framework, like past commitments from the biodiversity convention, will require protected areas to be “ecologically representative.” But Williams says “it is not clear the degree to which anyone [has] really checked this. The headline is normally the total area protected.” So some ecosystems get much more attention than others.

Iconic tropical rainforests often attract greater protection than dry tropical forests in the same countries that are at much greater risk from conversion to agriculture. This bias can push ecological destruction into unprotected areas. For instance, increased protection of the Brazilian Amazon in the early (pre-Bolsonaro) years of this century appeared to encourage deforesters into the country’s Cerrado region of minimally protected dry woodlands, which lost trees four times faster than the Amazon in the decade from 2008.

Ana Buchadas of the Humboldt University of Berlin recently estimated that tropical dry forests covering an area twice the size of Germany have been lost globally since 2000, along largely unprotected frontiers in the Gran Chaco and Cerrado regions of South America, parts of Southeast Asia, and increasingly in Africa.

A flock of rheas gather in a soybean field in Brazil’s Cerrado region, where farms have expanded into unprotected dry tropical forest. 
YASUYOSHI CHIBA / AFP VIA GETTY IMAGES

Many other underappreciated “Cinderella ecosystems” have been marginalized when countries set conservation priorities. In a global analysis with Munich colleague Matthias Biber and Alke Voskamp, of Senckenberg Biodiversity and Climate Research Centre in Frankfurt, Hof found that protected areas on land are rarest in hot deserts such as the Sahara and the Arabian peninsula. Deserts contain many rare species uniquely adapted to the dry conditions, yet policymakers often regard them as ecologically worthless. Hence the growing enthusiasm in some countries for planting trees to “green” deserts and capture carbon.


A more fundamental question that many believe should be asked in Montreal is how well the present model of protection works. There is growing concern among ecologists and others about whether top-down protection by governments is the best way to deliver effective biodiversity outcomes. In many developing countries, supposedly protected areas are little more than “paper parks” with minimal on-the-ground policing or management. And where park authorities are engaged, the result is often conflict with local communities.

In the run-up to COP15, a coalition of Indigenous rights groups, including Survival International and Amnesty International, condemned the 30-percent target as likely to “devastate the lives of Indigenous peoples.” It would encourage the continued adoption by governments of “exclusionary protected areas” that have in the past resulted in “widespread evictions, hunger, ill-health, and human rights violations,” the groups said in a joint statement.

Some worry a rush to achieve a 30 percent target will encourage state takeovers of lands being conserved by Indigenous communities.

Research backs up this concern. A recent land-use modeling study by Roslyn Henry of the University of Edinburgh and colleagues found that a “strictly enforced” 30 percent target for land protection that excluded farming from newly protected areas could cause up to 200,000 additional deaths annually from malnutrition by 2060, depending on how much of those areas was in low-income regions.

In any case, there is instead a growing realization that the most effective on-the-ground protection of biodiversity is frequently offered by locals themselves. Though often still seen by park managers as threats, the evidence is that Indigenous and local communities are often nature’s best defenders — especially when they have established collective rights to the land and its resources. Advocates of this bottom-up approach to conservation say it is no surprise that Indigenous lands contain an astonishing 80 percent of the world’s biodiversity.

“For Indigenous peoples and local communities, state-protected areas are a double-edged sword,” says David Kaimowitz, chief program officer at the Tenure Facility in Stockholm, which helps rural communities secure their land rights. “On the one hand they help them avoid threats from mining, logging, and agribusiness. But they often lose control over their territories. Governments usually refuse to recognize their land rights, and sometimes even expel them.”

An aerial view of an observation tower used by Indigenous Uaxactun in Guatemala to keep watch over their forest. 
ACOFOP

The international community has been slow to recognize the virtues of Indigenous conservation, says Kaimowitz. For instance, since its creation in 1990, the giant Maya Biosphere Reserve in northern Guatemala has seen areas under formal government protection widely illegally deforested, while neighboring forest lands controlled by local Mayan communities have repelled invaders far better, while providing a livelihood for forest communities.

A similar story is playing out in the governance of marine protected areas (MPAs). It is becoming clear that those MPAs that engage local fishing communities as partners rather than adversaries — by permitting rather than banning their activities — achieve the best conservation outcomes. “How MPAs are governed may be at least as important to conservation outcomes as the size of the area and the specific fishing regulations in place,” concluded Robert Fidler of Florida International University and colleagues in a study published in May.

The concern now is that a rush to achieve a 30 percent target for protected areas on land and at sea will encourage unilateral state takeover of lands already being managed and conserved by Indigenous communities, though often without a formal “protected” label attached. Nature, as well as those communities, could be the loser.

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