Science Shows How Nature Can Help Both the Climate and Biodiversity Crises

Reforestation (restoring forests in places where they historically grew), afforestation (adding forests in places like savannahs and grasslands), and bioenergy cropping (farming plants like switchgrass for renewable energy) are common strategies for helping the world meet its climate goals. Until now, it has been challenging to predict how these strategies will impact biodiversity because they affect species in multiple, complex ways. 

The team of scientists—including Jonathan Levine, Professor of Ecology and Evolutionary Biology at Princeton, and Dr. Evelyn Beaury, a former HMEI Post-Doctoral Research Scholar now at the New York Botanical Garden—found that reforestation will benefit many species both locally, by increasing habitat, and globally, by mitigating climate change. These include many iconic forest species from spotted salamanders and red-bellied woodpeckers to jaguars. 

"This research shows fighting climate change is not enough to safeguard biodiversity," says co-author Cook-Patton. "Some climate mitigation options are bad for biodiversity, but when done in the right places and in the right way, reforestation is a cost-effective way to address both the climate crisis and the biodiversity crisis."

The outcomes for planting monocultures of bioenergy crops or converting natural savannahs and grasslands to forests are not as rosy. While these efforts may help address climate change and reduce climate threats to biodiversity, they will also lead to immediate habitat loss. Replacing biodiverse meadows with bioenergy crops would be hugely detrimental for species from grouse to elk. Similarly, converting savannahs to forests would lead to the decline of iconic species like ostriches and lions. The study found that the loss of habitat due to afforestation and bioenergy would be far greater than the benefit they would provide to biodiversity by helping mitigate climate change. 

While ecologists have long suspected that some of these interventions would mean less habitat for creatures from turtles to tigers, this study provides the first quantitative assessment of these potential impacts. As Professor Levine points out, “Few ecologists doubt that addressing climate change would be a boon for biodiversity. However, our study finds that it’s not enough to reach net zero. It also matters how we get there.”

This research demonstrates that society should not seek solutions for either climate change or biodiversity loss in isolation. Instead, we must address these crises jointly to identify the best outcomes for wildlife and humanity.