Last Friday, the Lamont-Doherty Earth Observatory hosted Dr. Linda Elkins-Tanton for its yearly W.S. Jardetzky Lecture, titled “Volcanoes And The Great Dying: The End-Permian Extinction And Its Parallels With Today.” 

How many mosquitoes can you kill by snapping your field notebook shut in the middle of Siberia? According to Dr. Linda Elkins-Tanton, that number is somewhere between 10 and 15. 

A Foundation and Regents Professor in the School of Earth and Space Exploration at Arizona State University, Dr. Elkins-Tanton is also the vice president of the ASU Interplanetary Initiative, the Principal Investigator (PI) of NASA’s Psyche mission, and most recently, the W.S. Jardetzky Lecturer at the Columbia Climate School.

Of Dr. Elkins-Tanton’s diverse work, which ranges from the evolution of planetesimals (small bodies that coalesce during the formation of a solar system) to how to get scientists working together in interdisciplinary teams, Friday’s lecture focused on the conclusions of a years-long investigation into the causes of the End-Permian Extinction. Occurring around 250 million years ago, the End-Permian Extinction was the most catastrophic mass extinction for which we have fossil evidence–around 90% of ocean life and 70% of life on land came to an end. 

Unlike the more famous extinction of the dinosaurs, however, scientific consensus hasn’t yet settled on a reason for the End-Permian Extinction. Instead, her research argues that a slow-moving volcanic event in present-day Siberia, known as the Siberian flood basalts, was responsible for changes in climate that ended the Permian Period. 

Before diving into the specifics of her research, however, Dr. Elkins-Tanton shared a variety of fieldwork anecdotes that were in turns nerve-wracking, fascinating, and a bit gross. Her time studying the Siberian flood basalts involved riding in a bullet-ridden Soviet-era helicopter, petting a whole frozen mammoth in a museum in Khatanga, DIY-ing “dire inflatable boats” (in Elkins-Tanton’s words) to float down rivers and collect rock samples, and, apparently, killing 15 mosquitoes in one fell swoop by slamming a notebook shut. 

These expeditions yielded samples of burnt coal and volcaniclastics, or fragments of volcanic rock, that led Dr. Elkins-Tanton and her team to conclude that although the Siberian flood basalts were an effusive volcanic event, they nonetheless involved “energetic happenings.” Unlike explosive volcanic events (think Pompeii or Mount St. Helens), effusive volcanic events consist primarily of lava flows rather than volcanic eruptions. Still, Dr. Elkins-Tanton theorizes that the Siberian flood basalts were driven by a “world-record volume of volcaniclastics,” which erupted at high temperatures, releasing enough carbon, sulfur, and halocarbons to dramatically change the climate and cause a catastrophic global extinction. 

One of the most relevant and worrying takeaways from the lecture was how closely these vehicles of the End-Permian extinction resemble the symptoms of modern, anthropogenic climate change. In the Siberian flood basalts, Dr. Elkins-Tanton’s team found samples of burnt coal that resembled materials made exclusively by coal burning plants today. They also found evidence for naturally occurring halocarbons during the End-Permian, much like the infamous, man-made CFCs that have caused serious ozone depletion since the 1980s.

Using their data on the amount of carbon, sulfur, and halocarbons released by the Siberian flood basalts to model the climate, Dr. Elkins-Tanton’s colleagues found that rainwater would have become highly acidic, and atmospheric ozone would have repeatedly dropped below today’s levels, thus creating conditions hostile to life on land and in the oceans—perhaps driving the End-Permian extinction. 

Despite recognizing the difficulty of establishing with 100% certainty the causation between the acid rain and ozone depletion caused by the Siberian flood basalts and the End-Permian extinction, Dr. Elkins-Tanton characterized the conclusions of her team’s research as a “smoking gun.” In other words, climate changes involving atmospheric carbon, sulfur, and halocarbons were likely capable of causing the worst mass extinction we have on record. 

As for the similarities between the End-Permian extinction and anthropogenic climate change? According to Elkins-Tanton, the picture of the End-Permian painted by her research is nearly identical to what’s happening today–a bleak cautionary tale for how human-driven climate change could end, should we continue to let it run rampant. 

Explore more events hosted by Columbia’s Lamont-Doherty Earth Observatory here, and look for Bwog’s weekly science fair for more science events on campus like this one. 

Trilobite Fossils via Flickr, James St. John.