Fred Pearce writes:

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.

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. [Continue reading…]