Trading extinction?: Princeton researchers reveal the biodiversity trade-offs of global trade

Trade-induced farmland expansion is a major factor that drives threats to wildlife species. As countries increasingly import agricultural goods from abroad, they outsource much of the environmental damage and land clearing required to produce these products. This shift is fueling rapid agricultural expansion in ecologically sensitive regions, clearing forests for export crops such as palm oil and rubber.  A new study led by Princeton researchers reveals how these global trade markets are reshaping the geography of habitat loss - and consequently, the future of biodiversity. 

“We’ve known that international trade is important because it affects where people make changes to the environment,” explains lead author Alex Wiebe, a doctoral student in the Department of Ecology and Evolutionary Biology.  “But we haven’t had real expectations about how trade affects patterns of animal extinctions - does it speed them up, or slow them down, or both?”

The Data

The authors combined two methods for this study: First, the research team adapted a model originally used in epidemiology - the Susceptible-Infected-Recovered (SIR) model - to track how natural ecosystems are converted to farmland, and how that farmland is later abandoned. Second, the authors compiled a time series dataset of bird extinctions over the past five centuries (1500-present), which they used to evaluate how extinction patterns have changed over time in the real world.  The researchers then compared those patterns to the predictions of their theoretical SIR model.  

“It’s the first major time-series dataset on animal extinctions from the last few centuries,” says Wiebe.  “We haven’t had those kinds of data before because it is hard to say exactly when a species goes extinct, but we need to estimate those things in order to understand how patterns of extinction have changed over time.”

The Findings: International Trade a Double-Edged Sword

The findings reveal that approximately 131 bird species have gone extinct due to habitat loss since 1500.  However, this loss is part of a larger, more complex picture in which international trade has a double-edged influence on biodiversity. 

In some regions, international trade slows the pace of extinction, while simultaneously accelerating it in others.  Specifically, the researchers found that extinction rates in economically developed countries have been steadily declining after reaching their peak in 1900, while rates in developing countries have steadily increased over the same period.  The study found that these patterns are likely a reflection of the economic and ecological differences between countries, including their volumes of trade and the average range sizes of their species.  

“When a country expands its farmland quickly for crops that it can export, it can cause extinctions suddenly because high international demand can drive a fast pace of expansion,” explains Wiebe.  “We’ve seen this recently, for example, with four bird species that were driven to extinction from cropland expansion in a single part of northeastern Brazil just in the last 25 years.”

The Implications

This study highlights a critical policy challenge: countries that benefit economically from agricultural imports may also be indirectly driving habitat and biodiversity loss abroad.  As a result, the researchers recommend that high-income countries implement policies that monitor biodiversity in exporting countries and fund conservation efforts around the world.  Otherwise, a new wave of worldwide extinctions may be triggered if export-oriented agriculture continues to expand. 

“What is so chilling about our model is that it suggests that we may soon see a steep rise in the overall rate of species extinction due to globalization,” said senior author and Princeton professor David Wilcove. “That rate has been falling in recent decades, but as more countries from the species-rich tropics expand their agricultural and forestry exports, we can expect to see a sharp uptick in species extinction. More than ever, we need to carefully monitor biodiversity to ensure this rise does not happen.”

The paper, “Trajectories of biodiversity loss and extinction from trade globalization,” was published in Current Biology on September 8th, 2025.  The authors of the article include R. Alex Wiebe (Department of Ecology and Evolutionary Biology, Princeton University), David S. Wilcove (Department of Ecology and Evolutionary Biology, the High Meadows Environmental Institute, and the School of Public and International Affairs at Princeton University), and Cornia E. Tarnita (Department of Ecology and Evolutionary Biology, Princeton University).  This research was supported by the High Meadows Foundation.