We’re headed for another mass extinction, says breakthrough UW study
New research shows the way the planet is warming up has staggering similarities to the "Great Dying".
That mass extinction event 250 million years ago nearly ended life on earth. New research out of University of Washington and Stanford determines, for the first time, the cause.
Researchers found that global warming (instead of other factors such as high acidity in the water) was the cause of the Great Dying in the Permian era. Rising temperatures and depleted oxygen levels left animals unable to breath.
Justin Penn and Curtis Deutsch of UW's oceanography department authored the study.
Deutsch said it's a scientific breakthrough. And he calls it very "sobering."
"We are seeing right now in the oceans," Deutch said, "the very same changes that we saw at the end of the Permian, that we know happened to cause the Great Dying. That is that the oceans are warming up — we've already warmed at the top of the ocean about a degree Celsius since the pre-industrial period — and the oceans are also losing oxygen.
"Globally, there's less oxygen in the ocean now than there was 100 years ago."
Before the Great Dying, ocean surface temperatures increased by about 20 degrees Fahrenheit. Deutsch said the earth is currently on track to reach 30 percent of those same warming levels. That is, unless greenhouse gas emissions are meaningfully reigned in.
The study illuminates another detail about the Great Dying that applies to the Northwest. Deutsch said animals in colder climates were most likely to die.
"Sitting here in Seattle, looking out over our part of the ocean, we are within that northern Pacific region that is expected to, and is indeed observed to, be losing oxygen at a faster rate than most other parts of the ocean," he said.
He said species in tropical areas are able to migrate to cooler climates, which isn't an option for animals relying on cold weather.
Deutsch added, "For those who live in the high latitudes and cherish their local marine ecosystems, this is perhaps even a more concerning finding."
The study ends with a (slightly) optimistic outlook. There's a large difference between the Permian era and modern times: human life.
"We get to choose the degree to which the climate warms up by limiting our greenhouse gas emissions", Deutsch said. "We get to decide how much warming to allow. But it's clear that if you don't check it then marine ecosystems are in trouble."
The study was published December 7 in the journal Science.