Some efforts to preserve or rewild natural habitats are shifting productive landscapes to other parts of the world—and this could drive an even steeper decline in the planet’s species, according to a team of conservation scientists and economists led by the University of Cambridge.

Researchers from over a dozen institutions worldwide have come together to call on the global community to acknowledge the “biodiversity leak”: the displacement of nature-damaging human activities caused by designating certain areas for protection or restoration.

They argue that rewilding productive farmland or reducing forestry in industrialized nations that have low levels of biodiversity may do more harm than good on a planetary scale.

Exploratory analysis by the team suggests that reclaiming typical UK cropland for nature may be five times more damaging for global biodiversity than the benefit it provides local species, due to the displacement of production to more biodiverse regions.   

While this “leakage” has been known about for decades, it is largely neglected in biodiversity conservation, say the researchers. They argue it undermines actions ranging from establishing new nature reserves to the EU’s environmental policies.

“It is amazing we are so far behind on addressing, or even acknowledging, leakage effects in biodiversity conservation,” said University of Vermont professor and study coauthor Brendan Fisher. “In every other domain in our lives, we think about the net effects of a decision. When we buy a house, a car, even a book, we think both about the benefit of that good and the cost. Yet, so often in conservation, we forget that the costs might happen to someone else, someplace else or at a later time.”

, the experts point out that even the UN’s landmark Global Biodiversity Framework—aiming for 30% of the world’s land and seas to be conserved—makes no mention of the leakage problem.

“Every time we plot out a new protected area, demand a new agriculture practice that decreases yield, or protest a logging concession, we need to think about how the impacts of these decisions reverberate through markets and into other parts of the world,” Fisher, a Gund Institute for Environment Fellow and Professor in the Rubenstein School of Environment and Natural Resources, said. “If protesting a logging concession in the United States increases demand for pulp from the tropics, then we are unlikely to be helping biodiversity.”

Coauthor Ben Balmford of the University of Exeter said, “This issue demands far greater attention from a sector that seeks to shape how 30% of an ever-hungrier and more connected planet is managed.”

‘Leakage’ is already a major issue for carbon credits tied to forest preservation, say researchers. But they argue it’s a real problem for biodiversity conservation efforts too.

While protected areas can slow deforestation inside their borders, there’s evidence it can simply shift to neighboring areas. Production can also be displaced much further. Efforts to protect the Pacific Northwest’s old-growth forests resulted in increased logging in other North American regions, for example.

The researchers explored how leakage caused by protected areas could affect global biodiversity by applying real-world food and biodiversity data to two hypothetical conservation projects.

They found that rewilding a sizeable area of Brazilian soybean farms would push production to nations such as Argentina and the United States, but because Brazil is so important for biodiversity, the local conservation gains could be around five times greater than the displacement harms.

The experts offer a number of ways to help plug the biodiversity leak. They call on governments and the conservation sector to take leakage far more seriously when making environmental policy at national and global levels.

They also point out that leakage could be reduced if conservation projects work with others to reduce demand–especially for high-footprint commodities such as red meat.

There’s scope to limit leakage by targeting conservation to areas high in biodiversity but where current or potential production of food or timber is limited, say researchers. One example is restoring abandoned tropical shrimp farms to mangroves.

However, we should also be much more cautious about restoring natural habitats on currently productive farmland in less biodiverse parts of the world, they argue.

Beyond planning where to conserve, major conservation initiatives should work with partners in other sectors to support local farmers, so that overall levels of production are maintained in the region despite protected areas. The team cite examples ranging from forest-friendly chocolate to herding practices that protect snow leopards. Meanwhile, where local yield increases are difficult, larger-scale programs could establish long-range partnerships with suppliers in the same markets to make up shortfalls in production.

Gund Institute for Environment Director and Rubenstein School of Environment and Natural Resources Professor Taylor Ricketts, and Gund Institute for Environment Global Affiliates Robin Naidoo of World Wildlife Fund and Alexander Pfaff of Duke University, were coauthors on this research. Alexander Pfaff was a 2024 Gund Institute Macmillan Scholar in Residence.

Gund Institute for Environment Global Affiliate Andrew Balmford of the University of Cambridge was the lead author on this research, and a 2024 Gund Institute Macmillan Scholar in Residence.