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Death probably came within an hour as the impact (now believed to be in the Yucatan) unleashed tsunamis that spilled dinosaur bones far from home.
As the emissaries of 190 countries gathered in Lima, Peru, for the annual conference on climate change -- dumping yet more carbon dioxide into the air -- I watched dinosaurs boiling to death on my TV screen.
A toothy beast rears up in pain before collapsing into a bubbly broth. Fires rage. Dust obscures the sun for years.
“Mass Extinction: Life at the Brink” (Dec. 21 on the Smithsonian Channel) investigates their death 66 million years ago with scenic stops in Siberia, China, Spain and Mexico.
Paleontologists squint at traces of bygone eras in massive cliff formations and talk about the future with marked concern.
Are we on the brink of another mass extinction?
By way of answer, Sean B. Carroll, an evolutionary biologist and the documentary’s executive producer, focuses on two of the five mass extinctions that rearranged our planet.
The death of the dinosaurs was preceded by an earlier, even more devastating extinction event -- the Permian period’s “great dying.”
Their causes are very different. An asteroid destroyed T-rex and its world. Volcanos belching toxic gases like giant coal plants doomed the creatures of the Permian. In an astonishingly short time -- 60,000 years, maybe less -- a rich variety of life disappeared, from insects to the dignified Dimetrodon, which ambled into oblivion balancing a sail on its back.
Source:
Evolutionary Biologist Sean Carroll, left, and colleague Kirk Johnson in Badlands, North Dakota.
Topped off by a blue beret, holding up a tiny fossil, geologist Walter Alvarez talks lovingly about the beauty of rocks and the secrets they reveal.
“They lie there for millions of years and remember what happened when they were formed.”
Alvarez and his father, Luis, a Nobel Prize-winning physicist, first proposed the asteroid theory in 1981. Their proof was a ribbon of iridium that decorates cliffs all over the planet, separating the era of the large reptiles from the era of mammals. Iridium is rare in the earth’s crust, but plentiful in asteroids.
Alvarez senior calculated that even a smallish asteroid six miles in diameter slamming into the earth at 50,000 miles per hour would unleash the destructive force of 100 nuclear bombs.
Down went the mighty Tyrannosaurus Rex.
Death probably came within an hour as the impact (now believed to be in the Yucatan) unleashed tsunamis that spilled dinosaur bones far from home. The horror is splendidly recreated by the program’s inspired designers, who also go to town on cataclysms to come.
Humans, as many have noticed, are as good as volcanos and asteroids in animal removal. About one fourth of all mammals are threatened by extinction. The number of African lions, for example, has decreased from 400,000 to 30,000 in the past 70 years.
By end of century, the acidification of the ocean will equal the great dying of the Permian. No more snorkeling.
“Mass Extinction” lays out hope for some kind of awakening while offering convincing evidence that we are well into the Sixth Extinction. (Elizabeth Kolbert describes efforts both heroic and comic to save a few creatures before they join the dodo in her sorrowful “The Sixth Extinction”).
The grizzly bear seen wandering around Yellowstone National Park might well be wondering what happened to the white bark pine nuts that once cascaded from the heavens. The warmer temperatures no longer kill the beetle that chomps on the trees that dropped the pine nuts.
We are changing the world’s atmosphere in ways that rival past destructions. We are also producing politicians with reptile brains and corporate titans obsessed with short-term profits. Just recently, a bunch of state attorneys general united to fight the Environmental Protection Agency at the behest of energy companies.
I didn’t make that up.
Meanwhile, the glaciers outside Lima continue to melt.
