Climate change is set to contribute to a mass extinction event even if governments around the world actually meet the Paris Agreement goals, according to a study published Wednesday in the journal Climatic Change.
This is especially true in places like the Amazon and the Galapagos, where endemic species thrive yet are threatened by a shrinking habitat. Half of the plant and animal species in 33 terrestrial biodiversity hotspots that the World Wide Fund (WWF) has prioritized could become extinct by the year 2100 if global temperatures rise to 4.5 degrees Celsius above pre-industrial levels. These hotspots dot all corners of the world from Madagascar off the coast of Southeast Africa to the Chihuahuan Desert in North America.
Even if nations help keep the global temperature to 2 degrees Celsius above pre-industrial levels, which is where the Paris Agreement draws the line, biodiversity hotspots could lose up to 25 percent of the nearly 80,000 plant and animal species living in them.
That’s no small loss. It’s better than half, sure, but the extinction of a quarter of species could set off a disastrous cascade effect across ecosystems. The report doesn’t appear to take into account other factors that contribute to species loss, like habitat degradation.
“Within our children’s lifetime, places like the Amazon and Galapagos Islands could become unrecognizable with half the species that live there wiped out by human-caused climate change,” said WWF CEO Tanya Steele in a press release. “Around the world, beautiful iconic animals like Amur tigers or Javan rhinos are at risk of disappearing, as well as tens of thousands of plants and smaller creatures that are the foundation of all life on Earth.”
Some of these areas will be hit harder than others. Take the Miombo Woodlands in south-central Africa, for example. Its extinction numbers are more like 90 percent in the worst-case scenario because the temperature rise would make much of the region uninhabitable for those already there. Amphibians? Maybe just 10 percent would remain. Birds? They’d fare a bit better at 14 percent. Mammals? Let’s hope 20 percent survive.
A change in rainfall—a symptom of climate change—will further impact wildlife. Some like the Sundarbans tigers in West Bengal, India, might find their breeding grounds underwater. Others like the African elephant might have trouble finding water to drink. Hopefully, these animals are able to disperse and adapt to new homes. In that scenario, researchers found their likelihood of extinction decreases.
Extinction is happening with or without climate change (due to a variety of other human-driven factors like pollution or deforestation), and climate change leading to extinction isn’t news. What’s notable about this study, however, is the shortfalls of the Paris Agreement.
Its terms may help keep greenhouse gas emissions from throwing the planet into an apocalyptic nightmare, but without U.S. support, the apocalypse might come sooner than we’d hoped.