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New Documentary Warns Humans Could Be Responsible for Mass Extinction

Howard Hughes Medical Institute

The film Mass Extinction: Life at the Brinkreveals what scientists have learned about two cataclysmic events that extinguished nearly every plant and animal on earth; and rising concerns that humans could cause the next disaster.

Evolutionary biologist Sean B Carroll is the film’s executive producer. He also runs a lab at UW-Madison.

Carroll says as scientists have learned more about what it takes to turn the world’s ecosystems topsy-turvy – specifically during the time of the dinosaurs, called the K/T Extinction, and “The Great Dying” which occurred 250 million years ago.

“We now know with high confidence from really recent work (The Great Dying) was caused by massive volcanic eruptions underneath present-day Siberia; and that just pumped massive amounts of climate-changing gases, including massive amounts of carbon dioxide,” Carroll says.

Scientists have tracked down evidence of the event in ancient rock formations.

“It had a dramatic changes of temperature across the world – both on land and in oceans. In a relatively short amount of time, the majority of life on the planet went extinct,” Carroll says.

As for the K/T Extinction, a chemical trapped in other rock formations provided the first clue in the dinosaur’s demise.

“A chemical called iridium is rich in asteroids, but rare on the earth. But it took ten or eleven years for scientists to find the impact site which is in the Yucatan in Mexico,” Carroll says.

Up until then, Carroll says there was a great deal a doubt that an asteroid had caused the mass extinction but, “when that impact site was found, people understood the scope of the impact and what that would do in terms of blasting debris out of the atmosphere and having it ran back down on the planet, Hundreds of places around the globe have been found where that debris rained back down.”

Carroll says scientists now know that the earth could again face the magnitude of temperature change that happened millions of years ago.

The documentary warns - as humans reduce habitat for other species and alter the atmosphere, we are pushing plants and animals toward extinction around 12 times faster than normal rates.

For example: --Temperatures may rise by nine to eleven degrees Fahrenheit by the end of the century - a rise almost as great as during the end-Permian era, which preceded the age of dinosaurs. --Most of the coral reefs on Earth may vanish by the year 2070 - that would mean the loss of 25% of the fish species in the sea that depend on coral reefs ˜ and loss of 10% of the ocean's fisheries that humans depend upon.

Credit Tangled Bank Studios
Dead White Bark Pine trees attacked by pine beetles in Yellowstone National Park.

“This is why a lot of my colleagues are really anxious. The more we understand about past mass extinctions, even if they were caused by different triggers, they had their effect through a common means, which was unleashing these climate-changing gases and changing the course of life across the earth,” Carroll says.

Mass Extinction: Life at the Brink premieres on the Smithsonian Channel this Sunday, November 30th.

"The scientific community that I joined in making this documentary would say, yes there is the possibility of avoiding a mass extinction; there are a lot of species that can be saved; we've just really got to make a commitment to it,"  Sean B. Carroll says.

Susan is WUWM's environmental reporter.<br/>