When I was a kid, I wanted to grow up to be a paleontologist. It seemed so unfathomable that creatures so alien once ruled the earth. Something about the ferocity silenced by even more violence holds my fascination more than any mystery thriller ever will. Now imagine my excitement when I found out that our group was going to be visiting the Two Medicine Dinosaur Center to talk about climate change. Two of my favorite topics in one — fossils and fossil fuels.
The ride that day was beautiful and quiet. Rolling hills covered in mustard, wheat, and alfalfa fields and roaming herds of cows. I need to tell you that passing cow pastures is so much fun because bicyclists seem to have a unique effect on them. We aren’t cars, which they are used to by now, but strange creatures out to get them. When the first in our group starts to pass they look surprised, then fearful. Then the mooing starts and by the last person, we’ve started a stampede. Poor things. Horses and antelope, on the other hand, have a very different response to bicyclists, which seem to inspire them to run, not away, but with us.
Anyway, the tiny town of Bynum, along the Rocky Mountain Front, has an established agate shop, converted from an old church, and a museum housing the biggest model dinosaur in the country. It’s the town’s main attraction. It’s also home to David Trexler, a paleontologist, climate scientist, and author. We filed into his conference room, and Trexler quickly turned our worlds upside down. Out of all the speakers we’ve had so far, I think Trexler scared us the most.
Trexler first took us through earth’s 4.55-billion-year history. Molten lava, flying rocks. A dry, hot, fiery place that over billions of years began to bear life. Oceans spawned plankton, which sequestered carbon dioxide, released oxygen, and eventually developed the earth’s breathable atmosphere. Dinosaurs eventually evolved, and many changes occurred in the environment that dictated the course of their development and ultimate demise. There have been mass extinctions over the course of earth’s history, caused mainly by rapid changes to the environment, and evidence of the changes is embedded in the earth, giving scientists clues to planetary trends — and insight into what’s to come.
Today, as Trexler explained, we’re dealing with similar changes to the earth’s atmosphere due to the rate at which we burn fossil fuels. Trexler told us that never in earth’s history have we seen such rapid increase in CO2 in our atmosphere in such a short amount of time, and the spike could result in another mass extinction. One of the most striking changes is ocean acidification. Ocean pH has dropped from 8.2 to 8.1, a 25 percent increase in acidity over the past two centuries. Trexler predicts that if the pH drops to 7.8 (expected by 2100 at today’s emission rates) carbon-sequestering plankton will die off, resulting in a dramatic increase in carbon dioxide, and amplifying positive feedback loops already warming the planet.
At a certain point, Trexler said, the heating could reach methane clathrates, which are basically massive deposits of methane ensconced as ice-like crystals on the ocean floor. If large amounts of that methane — which has about 20 times the greenhouse effect as carbon dioxide — is eventually released, a series of chemical exchanges would occur sharply reducing levels of atmospheric oxygen. Sometime in the not-too-distant future, he said, air at sea level could contain the same amount of oxygen as what’s now found at 17,000 feet. I never thought climate change adaption could include oxygen tanks.
While Trexler’s science diverges from most other climatologists in that he’s considering an entirely different timescale, his prescription is largely the same: the carbon we emit must equal the carbon we put back underground.
– Hannah Plowright