Biodiversity Conservation Faces an Evidence Crisis: A Call for Reform

Biodiversity loss is continuing at an unprecedented rate, with species becoming extinct at between 100 and 1,000 times the average pre-human, or ‘background’, rate. Human activities are the main cause. Although there are hundreds of local, regional and international initiatives to conserve and sustainably use species and ecosystems, many conservation scientists worry that measures such as interventions to conserve individual species or incentives to create protected areas are not supported by strong evidence from research.

Biodiversity is disappearing at a pace unlike anything in human history. Species are going extinct at rates between 100 and 1,000 times higher than the natural background rate that existed before humans began dominating the planet. While human activity is the clear driver of this loss, there is a troubling gap in our understanding. Although there are hundreds of programs locally, regionally, and internationally designed to protect species and ecosystems, many scientists worry that these efforts lack a solid foundation of evidence. Interventions to save specific species or incentives to create protected areas are often implemented without rigorous proof that they work.

"It always astonishes me how, while drowning in an ocean of information, we still don't have the scientifically based answers to very simple questions," said Sandra Díaz, an ecologist at the National University of Córdoba in Argentina. This sentiment highlights a critical flaw: we have data, but we lack the synthesized knowledge needed to make effective decisions.

This week, scientists are gathering in Manchester, United Kingdom, for the annual conference of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). This organization serves as the global authority on biodiversity issues, functioning for the natural world much like the Intergovernmental Panel on Climate Change (IPCC) functions for the climate. The IPBES provides authoritative scientific assessments based on requests from governments.

Although improving the availability and use of strong evidence in policymaking may not generate headlines, it must be a top priority for the IPBES, just as it is for the IPCC. Last month, conservation scientists and practitioners met in Cambridge, United Kingdom, to discuss what the Wildlife Trusts, one of Europe's largest conservation organizations, has termed an "evidence emergency." The meeting produced a consensus on two critical points.

First, the quality of evidence used to create conservation policies needs significant improvement. For example, in northern India, decades of tree-planting schemes failed to increase forest canopy cover. This failure occurred because planners did not account for the underlying reasons why the forest cover was being lost in the first place.

Second, it remains difficult for non-academic practitioners to find reliable information about what strategies work and which do not. The vast academic literature is not organized in a way that allows these users to quickly find answers to their practical queries. "There's a tremendous amount of information in the scientific literature, but it's largely inaccessible," explained Shahid Naeem, an ecologist at Columbia University in New York City who was not present at the meeting. However, this situation is beginning to change. A solution inspired by the synthesis of literature reviews in medicine is now being deployed. A prominent example is the initiative Conservation Evidence, which is based at the University of Cambridge.