Scientists say wildlife extinction has become a problem — a really big problem
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In the last decade, climate change has vaulted to the top of the list of the world’s environmental problems.
Scientists say that a warming planet may help trigger other events, such as a collapse of ecosystems across the planet, and that a mass extinction could be on the horizon.
Climate change has sparked a number of events across the planet: Melting glaciers, rising oceans, a shrinking Colorado River, wildfires and drought.
These things can have a big impact on wildlife, said Aaron Weiss of the Center for Western Priorities, a Denver-based nonprofit.
“There are two intertwined crises happening right now,” Weiss said. “There’s the climate crisis, and there’s the nature crisis, which some scientists have described as the beginnings of the sixth mass extinction.”
Researchers say that Earth has experienced five mass extinctions. The most famous collapse took place when the dinosaurs died off. The sixth extinction is different: It’s human caused.
“So the climate crisis, and the nature crisis are forever intertwined. We can’t really address one without addressing the other,” he said.
Climate change once seemed abstract, like something that might happen in the future.
Scientists warned that a change of a couple of degrees Celsius would have consequences, but Americans typically don’t use the Celsius scale.
“Well that’s the difference between a 100-degree day and a 105-degree day. So what if every 100-degree day in Arizona became a 105-degree day, and every 105-degree day became a 110-degree day?” he said.
But wildfire smoke and falling reservoirs across the West got everyone’s attention.
Climate change has jumped to the front of the line of environmental problems. Americans have begun to recognize that climate change is a problem, but Margaret Evens, a biologist with the University of Arizona, said that the idea of a mass extinction does not yet resonate with the public at large.
“I think people are becoming more and more aware that the climate change issue that is not something we need to worry about in the future, that it’s happening now,” she said. “And is affecting people now. With the biodiversity crisis I think it’s a little harder for people to see how does it impact me?”
She says because Americans spend so much time indoors, they’ve lost touch with what’s happening outdoors.
“So many of us live in cities, where we’re really disconnected from nature, and the interdependence between people and nature has been severed,” Evans said.
In Arizona, the list of endangered or threatened species includes the jaguar, the California condor, the Sonoran pronghorn and the black-footed ferret.
The cactus ferruginous pygmy owl faces threats from sprawl and climate change. Roads, dams, agriculture and pollution can push some species to the brink. Poachers and an illegal wildlife trade affect others, said Gary West, a veterinarian at the Phoenix Zoo.
“I think we’re degrading habitat, and wildlife trade and wildlife consumption is probably pushing animals to extinction, I feel, at a much more rapid rate than maybe climate change is,” West said.
As more species have struggled in the wild, a number of zoos have started breeding programs.
The Phoenix Zoo has worked with the black footed ferret, the Chiricahua leopard frog, the cactus ferruginous pygmy owl, the narrow-headed garter snake, the Mount Graham red squirrel and desert bighorn sheep, species native to Arizona. West also travels abroad to work with other species.
“Probably 25 years ago is when I got into zoos you know they talked about zoos are sort of arks, or sort of places where we’re going to save species, and I was always skeptical of that,” West said. “But now I do think that zoos are really one of the primary sources for educating the public on the plight of endangered species and really contributing to the conservation of endangered species, either through educational messages at the zoo or direct action such as work that we’re doing in the field. So I think zoos have a really critical role to play there.
Researchers struggle to track extinction. For one thing, they haven’t identified every species, so we could lose some without ever knowing it. Tigers and pandas make headlines. Bugs or plants don’t, yet they can lay the foundation for entire ecosystems.
Some scientists say the sixth extinction is part of what could be the next geological age, the Anthropocene.
Roy Plotnick, a professor emeritus at the University of Illinois Chicago, says that some call it the Homogocene.
“You know we have homogenized the world’s biota. Things that, you know, when I look outside my window where I live, I see lots of house sparrows. Those are not from here. So animals have been transported around, you know they have pythons in Florida, for God’s sake,” Plotnick said.
The idea of a human-cause mass extinction raises moral questions as well as practical ones. What happens if we lose pollinators, like bees? What if we lose fish? It could take centuries to get to the point of collapse, but he says most researchers believe a mass extinction is underway.
“But again, how it compares to the previous extinctions is very hard to say,” he said.
He calls it a data comparison problem. Only a fraction of all species make the fossil record, so it’s difficult to tease out how the past can inform the present.
“But I don’t think you can say oh, it’s not happening. It is happening, it’s just very hard to put it in exactly the same context as the previous extinctions," he said.
By most accounts, we’re not there yet, but the line between an abstract future, and the present may soon begin to blur. And like climate change, a mass extinction could have consequences.
EDITOR'S NOTE: The story has been updated to correct that Roy Plotnick is a professor emeritus at the University of Illinois Chicago.
