There’s a rule of thumb when it comes to species extinction: if you have 90 percent habitat loss, you lose half of the species dependent on that habitat. That’s what William F. Laurance told the audience at a recent bonus Frontiers in the Environment presentation, “The Future of Biodiversity.”
Are we on the verge of an extinction crisis?
Laurance is distinguished research professor and Australian laureate at James Cook University in Cairns, Queensland, Australia, and the Prince Bernhard Chair in International Nature Conservation at Utrecht University in the Netherlands.
The rule of thumb, he said, is used to answer a big question: Are we on the verge of an extinction crisis? The answer depends on how you calculate the rate and range of habitat loss.
One problem is, we don’t know what factors leading to habitat loss will have the most impact on species extinction. Another is that we don’t know how many species exist on the planet. “There is a great amount of uncertainty,” Laurance said.
We do know where the richest biodiversity is found: in wet tropical regions, Mediterranean climates and global centers of endemism, such as islands, mountains and coasts, he said.
“It has been discussed by many authors that, by 2050, only 5 to 10 percent of old growth tropical forest will likely survive. Perhaps 50 to 75 percent of all tropical species would become extinct or committed to extinction based on species-area curves,” Laurance said.
But some studies suggest the numbers may not be as bleak. Like to learn more? View the video of Laurance’s talk here. And as your time allows, we welcome you to view past Frontiers on the Environment presentations on topics from Alaska to watersheds.
Monique Dubos is a freelance writer and photographer. She currently works at the University of Minnesota.