We are in a race to save the world’s biodiversity – from the smallest insect to the largest mammal – in the face of an uncertain future. Last month, world leaders met at the 15th Conference of the Parties (COP15) to the United Nations Convention on Biological Diversity (CBD) in Montréal to discuss an action plan for halting the alarming rate of biodiversity loss. Approximately 1 million plant and animal species are at risk of extinction, and climate change is one of the primary reasons for that extinction threat, along with habitat destruction. But it is not too late to change course.
At COP15, close to 200 countries reached a monumental agreement to conserve 30% of Earth’s lands and waters by 2030 as a means of stemming biodiversity loss. The Biden administration’s own U.S.-based 30 by 30 plan is outlined in the America the Beautiful Initiative, which calls for a decade-long effort to support locally-led and voluntary conservation and restoration efforts across the nation’s public, private, and Tribal lands and waters. While the initiative outlines key strategies, including collaborative approaches with farmers and ranchers, there is a glaring gap in the plan: exactly where are the places that we should conserve.
In our study published in Frontiers in Ecology & the Environment, we identified locations in North America likely to sustain biodiversity under varying levels of climate warming. These areas are known as climate refugia. There are many ways to identify areas that are biologically valuable – from locations with many species to those with rare species to those that are relatively undisturbed. Yet all of these approaches only consider places that are currently important. In our study, we argue that to protect our future, we need to attempt to predict the future.
Our study’s findings sound an urgent call to action that beyond 2°C of warming, our options for conserving refugia will be greatly reduced. With this level of warming, the majority of refugia will occur only at high latitudes and elevations, drastically limiting conservation opportunities. Because the availability of refugia for plants specifically -- which account for more than 50% of terrestrial species -- is drastically reduced above 2°C of warming, we demonstrate that biodiversity is poised to reach a critical tipping point beyond which there may be cascading effects on other organisms. Such a transformation would negatively affect wildlife and humans alike.
We also found a partial mismatch between locations of refugia for amphibians and reptiles with those for one of their main food sources – invertebrates. This result is yet another warning sign that there are likely to be bottom-up consequences of climate change to biodiversity in North America.
To counteract this possibility, we need to build a conservation framework that includes stewardship, incentives, restoration, and protections that will withstand the test of time and provide refuge for all species as they adapt to the changing climate. Our research found that less than 15% of refugia for terrestrial biodiversity are currently protected in North America. As the federal government implements the 30 by 30 initiative, climate refugia should be carefully considered in conservation efforts.
Aiming to more closely align 30 by 30 conservation efforts with refugia represents a compelling strategy for efficiently spending limited conservation dollars and hedging our bets in the face of an uncertain future – these are places we are relatively confident will be resilient to climate change and thus provide protection to the wildlife and plants therein well into the future.
Currently, the majority of U.S. 30 by 30 proposals lack explicit consideration of refugia. Likewise, initiatives for protected area expansion in Canada have focused on conserving ecosystem services first and biodiversity second. Working across national borders will be critical for converging on broad-scale strategies to ensure that climatically suitable areas will be available for species shifting their ranges throughout North America. Additionally, adoption of new policies and renewed investments in current conservation programs that incentivize improved management and restoration of refugia on private lands are essential to achieving effective conservation in a changing climate.
The path to achieving forward-looking conservation targets is clear: we call on the Biden administration to adopt stringent climate change mitigation goals along with strategic incorporation of refugia into land management. These strategies will require coordination and collaboration within and outside of US borders, as demonstrated at COP15. Both biodiversity and humanity hang in the balance because of our warming world. Let’s give it – and ourselves – a fighting chance.
Dr. Saunders is a research scientist at the National Audubon Society and Dr. Meek is an assistant professor in the department of Integrative Biology, AgBio Research, and the Ecology, Evolution, and Behavior Program at Michigan State University