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Climate Change, Politics, Public Health, Public Policy, Science

Earth Has Entered First ‘Mass Extinction’ Since Dinosaurs, Scientists Warn

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The Earth has entered its sixth mass extinction phase, a new study warns, and the time we have to avoid dramatic consequences is rapidly running out.

Vertebrates — which include mammals, birds, reptiles, amphibians and fish — are disappearing at a rate 114 times faster than normal, according the study published Friday in the journal Science Advances. The number of vertebrate species that have gone extinct in the last century normally take 800 to 10,000 years to disappear under natural extinction rates, the researchers said.

“These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way,” the researchers wrote.

And those are the conservative estimates. “Our calculations very likely underestimate the severity of the extinction crisis,” noted study co-author Dr. Paul Ehrlich. “There are examples of species all over the world that are essentially the walking dead.”

While the most famous mass extinction phase is the one which many scientists believe killed off the dinosaurs, there are five known extinction phases that predate it, including the Great Dying 248 million years ago in which 96% of species perished. The dinosaurs were eventually killed off by an asteroid about 65 million years ago.

Now, scientists say, human activity related to development and climate change are exacerbating the extinction risk for species around the world.

“Our analysis emphasizes that our global society has started to destroy species of other organisms at an accelerating rate, initiating a mass extinction episode unparalleled for 65 million years,” the researchers wrote. “Avoiding a true sixth mass extinction will require rapid, greatly intensified efforts to conserve already threatened species and to alleviate pressures on their populations — notably habitat loss, overexploitation for economic gain, and climate change … However, the window of opportunity is rapidly closing.”

The study found that given these extinctions, the benefits of biodiversity like crop pollination and water purification could disappear in as little as three lifetimes, putting the human species in serious danger before others.

“If it is allowed to continue,” lead study author Gerardo Ceballos told BBC News, “life would take many millions of years to recover and our species itself would likely disappear early on.”

These findings are just the latest in a startling line of research documenting the catastrophic effects of human activity on life forms of all kinds. In a similar study published in January 2015, an international team of 18 scientists warned that humans are “eating away at our own life support systems” at a rate unseen in the past 10,000 years, damaging the environment so gravely that the Earth will cease to be a “safe operating space” for our species.

That same month, the United Nations published a policy paper calling attention to the threat that climate change poses to the global food supply, which it described as one of “the most daunting challenges facing humankind.” Between 16 and 22 percent of wild crop species may be in danger of extinction within the next 50 years, the paper said, including 61 percent of peanut species and 12 percent of potato species. What’s more, research shows that the adverse effects of climate change on crop growth and biodiversity are compounded by increasing levels of air pollution.

Most recently, in May 2015, a meta-analysis of 131 published studies concluded that, if climate change continues at its current pace, one in six of the world’s species could be lost forever to extinction by the 2060s. The analysis — one of the most comprehensive studies of how biodiversity will fare in a warmer climate — discovered that the rate of biodiversity loss doesn’t rise linearly but actually accelerates with each degree of warming, highlighting the need for an urgent change of course.



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"Science is a way of thinking much more than it is a body of knowledge." -- Carl Sagan


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