Close to half of all living species on the Earth could disappear by the end of this century, and humans will be the cause.
This is the sixth mass extinction— a loss of life that could rival the die-out that caused the dinosaurs to disappear 65 millions years ago after an asteroid hit the planet.
This time, though, we’re the asteroid.
At least that's the finding of a recent study in the journal Science Advances.
The study found that animals are disappearing about 100 times faster than they used to and, ironically, humans could be among the first to go for good.
Not since the age of the dinosaurs ended 66 million years ago has the planet been losing species at this rapid a rate, said a study led by experts at Stanford University, Princeton University and the University of California, Berkeley.
The research, which comes on the heels of another similar study done last year, "shows without any significant doubt that we are now entering the sixth great mass extinction event," said co-author Paul Ehrlich, a Stanford University professor of biology.
"There are examples of species all over the world that are essentially the walking dead," Ehrlich said.
Humans may be one of them.
"If it is allowed to continue, life would take many millions of years to recover and our species itself would likely disappear early on," said lead author Gerardo Ceballos of the Universidad Autonoma de Mexico.
In her 2014 book, "The Sixth Extinction: An Unnatural History," science writer Elizabeth Kolbert warned of the same phenomenon. She'd been inspired to write the book after visiting Panama and reporting on the rapid decline of several frog species there.
"We are deciding," Kolbert writes, "without quite meaning to, which evolutionary pathways will remain open and which will forever be closed. No other creature has ever managed this, and it will, unfortunately, be our most enduring legacy."
The new analysis, which comes to some of the same conclusions Kolbert did last year, is based on documented extinctions of vertebrates, or animals with internal skeletons such as frogs, reptiles and tigers, from fossil records and other historical data.
Its authors described it as "conservative."
Nevertheless, they found that the "average rate of vertebrate species loss over the last century is up to 114 times higher than it would be without human activity, even when relying on the most conservative estimates of species extinction," said the study.
"We emphasize that our calculations very likely underestimate the severity of the extinction crisis because our aim was to place a realistic lower bound on humanity's impact on biodiversity."
The causes of species loss range from climate change to pollution to deforestation and more.
According to the International Union for Conservation of Nature, about 41% of all amphibian species and 26% of all mammals are threatened with extinction.
"There are examples of species all over the world that are essentially the walking dead," Ehrlich said.
The study called for "rapid, greatly intensified efforts to conserve already threatened species, and to alleviate pressures on their populations — notably habitat loss, over-exploitation for economic gain and climate change."
READ MORE: Earth is on the edge of a 'Sixth Extinction'
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