MS. REBECCA SHEIR
Okay, so now we're going to step way further back in time for a story about our prehistoric past and what it may be telling us about our future. Sabri Ben-Achour has the story.
MR. SABRI BEN-ACHOUR
The history of the past 100 million years is in a box in David Powars' home office in Winchester, Va. Powars is a geologist with the U.S. Geological Survey. So it kind of makes sense that his home office is basically an archeological site in and of itself. There are piles 6 feet high of maps and papers and boxes, fist-size drill bits.
MR. SABRI BEN-ACHOUR
He pulls out cylinders of rock and clay he drilled a few miles south of D.C.
DR. DAVID POWARS
Right here on the Potomac River.
The cylinders are samples of the bedrock from hundreds of feet below, so you can see all the layers of soil, mud, and rock from ages past. And these ones are mostly blackish green.
This green sand.
Powars can read this record like a book but instead of words, he sees microscopic fossils and layers of minerals and 55 million-year-old-poop.
Why it's called a green sand is these tiny little feces from the bugs that were living in it, that are little black and green minerals.
From looking at that old, poopy clay and the fossils inside Powars can tell that 60 million years ago the D.C. area was a calm, shallow sea where microscopic bugs could live their little bug lives gently swimming and pooping in peace. And then, 55 million years ago...
In the geological blink of an eye, the Earth totally changed and you can be seen in Powars' rock sample.
All of a sudden dramatically, bang, we go into this Kalinic rich clay.
The next layer in his rock sample is cream colored because all those happy green pooping bugs are gone.
All the bugs are missing.
All the shell fossils that were in the layer before are gone too, they've gone extinct.
The sedimentation rate during this short period, it increased ten-fold.
This bizarre new Earth is home to a lot of rain and a ton of massive storms. Mega rivers form between the Potomac and the Susquehanna and dump huge amounts of mud into the calm sea we used to have.
This was a big river-dominated shelf and it's like the Amazon. You got this big river that's just dumping out there and that's what these sediments tell us.
The Washington region, according these rocks, looked like the Amazon.
Something had to happen dramatic to do that.
What happened was climate change. In fossils all over the planet from this time, the carbon changes. Massive amounts of carbon entered the atmosphere and the oceans and the greenhouse effect intensified.
We had this major thermal maximum, the hottest time we know of and it came on very fast. It had worldwide effects on the climate and the oceans. It killed off a lot of stuff in the oceans.
How hot did it get?
So all of a sudden tropical fauna will be found and flora will be found up in the Arctic. Crocodiles, palm trees, rhinoceros.
The Earth's temperature rose 40 degrees Fahrenheit.
The shoreline was some place west of Richmond, west of D.C., some place on the Piedmont. We've just dated marine sediments west of Richmond and it rose another 10, 20 meters it's calculated. Some like to say five meters but even five meters in a short time would be a lot.
Nobody knows where the carbon that caused this change came from, could've volcanoes, could've been escaping gases. But scientists were able to calculate how much of it was released. Lee Kump is a professor of geosciences at Penn State University.
MR. LEE KUMP
The total quantity of carbon added to the atmosphere was something on the order of the quantity of carbon that we have in known fossil fuel reserves today.
So are we headed toward a future in which the Blue Ridge Mountains are ocean front property? Gavin Schmidt is a climate scientist at the NASA Goddard Institute for Space Studies. He says it's hard to say because the world 55 million years ago was pretty different to begin with.
MR. GAVIN SCHMIDT
There was no ice around, it was a very different base climate. So there was no huge continent of Antarctica covered in ice, there was no Greenland ice sheet. And so a lot of the things that we're worried about going into the future, going into this next century are associated with features that are kind unique to this climate.
Another difference, the thermal maximum carbon release took 20,000 years and the super warm period lasted 170,000 years. Humans could easily burn up all their fossil fuels in a couple hundred years and Lee Kump says in this case, speed matters.
The temperature rise, again, in the worst case scenario could be comparable to this extreme warming event in Earth history but even more critical here is that the rate of change is maybe a factor of ten faster.
There's a big difference between having 20,000 years to adapt to something versus having just a few hundred. I'm Sabri Ben-Achour.
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