"Conservation Is Not a Failure"
A new paper argues that success depends on measuring what works.
Ecologist Stuart Pimm is not exactly an optimist. After studying the rates and patterns of species extinctions for decades, he estimates that humans are accelerating extinctions by a thousandfold. His 2001 book, humbly titled The World According to Pimm, totted up the planet’s profits and losses from humanity and found us in serious debt.
But Pimm emphasizes that these ongoing catastrophes are not inevitable, and has long argued that conservation can work — if it collects, and follows, the necessary evidence. His latest review paper, published in the Proceedings of the Royal Society B, is a useful look at what’s known, what’s not known, and what’s needed to get to something like success. In an essay that accompanies the review, Pimm and his co-author John Gittleman write:
Conservation is not a failure — it’s actually achieving real results. But those results are uneven, sometimes inefficient, and often poorly tracked. The biggest limitation isn’t a lack of tools or knowledge about what works; it’s a lack of clear goals, consistent measurement, and transparency.
Pimm and his colleagues focus on the goals and targets adopted in late 2022 by the parties to the Convention on Biological Diversity, especially the goals of halting “human-induced extinction of known threatened species” and, by 2050, reducing the extinction rate and risk of all species by tenfold. Though these are admirably measurable ambitions, they note, the targets intended to get us there are pretty vague, except for the much-discussed drive to protect 30% of the planet’s lands and waters by 2030. (My friends in conservation social science would remind us that “measurable” doesn’t necessarily mean “quantifiable” — qualitative data is data, too.)
With such goals in mind, Pimm and his co-authors attempt to summarize global progress toward protecting habitats and halting extinctions. Protected areas have expanded significantly in recent decades, they write, but they’re disproportionately located in cold, dry, and remote places. Where they exist, they do seem to work, reducing land conversion by an estimated 50% even when places unlikely to be converted under any circumstances are excluded from the calculation.
Meanwhile, humans are still accelerating extinction rates, but conservation efforts have helped avert some imminent extinctions and, in hundreds of documented cases, slowed or even reversed population declines.
Much is unknown, of course, and much is not known widely enough. Pimm and his coauthors suggest that conservation researchers focus on four especially pressing knowledge gaps: habitat destruction in oceans and drylands (much more difficult to monitor via remote sensing than the felling of forests); the extent of meaningful forest restoration worldwide (versus the plantations of non-native tree species sometimes advertised as restoration); and the real and potential contributions of Indigenous- and other community-led conservation efforts (widely recognized but, as I’ve previously written, incompletely documented, making them vulnerable to sidelining by governments and conservation institutions).
Pimm and his colleagues warn against sweeping claims about the dire state of biodiversity. They condemn as “fanciful” the Living Planet Index, published by the World Wildlife Fund and the Zoological Society of London, which combines the population trends of tens of thousands of vertebrate species to estimate recent declines in global biodiversity. (The most recent index, published in 2024, estimated a 73% decline in biodiversity abundance between 1973 and 2020.) The practice of combining thousands of datasets to produce a single number is not only “irresponsible,” Pimm has said elsewhere, but “depresses people to no end” by obscuring the genuine, if limited, progress made in many places worldwide.
Pimm and his colleagues direct their advice to governments and large conservation groups, but there are lessons here for grassroots groups, too: any organization can benefit from setting measurable goals, consistently tracking progress, and communicating both successes and failures. Such efforts, assembled and distributed by projects like Conservation Evidence, can help humanity stop accelerating extinctions and instead accelerate recoveries — of populations, species, and the habitats they need.
Conservation At Work
For a deep dive into the many assumptions underlying the global goals and targets adopted under the Convention on Biological Diversity in late 2022, check out this thoughtful new paper in People and Nature.
Helen Pearson, longtime editor at Nature and a terrific science journalist, has a new book out called Beyond Belief: How Evidence Shows What Really Works. An excerpt published in Slate features an appearance by Bill Sutherland of the Conservation Evidence project. Anyone want to buy a bat bridge?
Worrisome evidence of a mental health crisis among conservation practitioners has sparked a valuable discussion in Mongabay: Jeremy Hance’s initial story in March led to a commentary by conservation leaders Vik Mohan and Nerissa Chao, a reflection by Mongabay founder Rhett Ayers Butler, a commentary by several young members of the Conservation Optimism movement, and another commentary, by conservationists Jen Miller and Kelly Guilbeau, on the work already underway to build a “culture of care” within the profession. Miller and Guilbeau are co-founders of Revive, a Society for Conservation Biology working group focused on emotional resilience, and their article points to several other groups and resources.
Did the reintroduction of wolves to Yellowstone National Park create a transformative trophic cascade? The story is a restoration parable —thanks to a 2004 study that was repackaged as a viral video — but recent evidence suggests that the Yellowstone wolves created not a trophic cascade but a “trophic trickle.” Here’s the latest critique and the original researchers’ defense.
Benji Jones, a senior correspondent at Vox, has an excellent explainer about the connection between gun sales and conservation. The initiated will know that the federal excise tax on firearms, ammunition, and archery equipment used to fund state wildlife agencies is a pillar of the North American Model of Wildlife Conservation — a game-centric model now in serious need of expansion, if not fundamental reimagining. Earlier this year, the Oregon Legislature took a significant step toward reforming the NAM when it passed a 1.25% increase in the statewide lodging tax to fund the implementation of the State Wildlife Action Plan.
Finally, try this in your town: my friend Sarah Fox recently hosted a delightful conservation storytelling event for our community called “Bear Rubs, Oak Cavities, and Other Love Stories from the Gorge.” Sponsored by the Columbia Land Trust, it celebrated the critters and people who shape our place — and ended with the tale of a conservation meet-cute for the ages. 😍
It's honestly a boost to read that there are folks who care that conservation workers are burned out and depressed. Just knowing it's not just being shrugged at... helps.
Thanks for this, Michelle. It's a bit of clarity in the noise/news of ecological loss and the push for conservation. I imagine there's a real tension in many cases between the urge to do something about a particular species or habitat and the years it could take to acquire enough data/understanding for the right course of action. And then there's waiting for the research funding... Not that this justifies those bat bridges, but it's another reflection of how complicated things are.