Colgate University’s Division of Natural Sciences and Mathematics (NASC) held the final iteration of its NASC Colloquium series with a presentation on Antarctic permafrost by Earth and Environmental Geosciences Professor Joe Levy on Friday, Dec. 5.
The presentation, titled “Thawing Antarctica’s Permafrost: Earth & Environmental Science Mystery,” was adapted by Levy from original student research projects and field research conducted by Colgate alumni Ian Andrews, Isabella King, Lily Kuentz and Gavin Fowler under Levy’s supervision.
According to Earth and Environmental Geosciences Department Chair Aubreya Adams, who introduced Levy at the talk, Levy’s work is wide-ranging, but focuses generally on sediment and permafrost. Research on the thawing of permafrost in Antarctica formed the bulk of the Dec. 5 presentation.
“His work has taken him to a number of locations, including dry deserts out West, to Namibia, remotely to Mars, but probably most importantly to Antarctica,” Adams said. “So today he’ll transport us all to Antarctica … and tell us about some of the things he’s come up with.”
During the presentation, Levy offered evidence that Antarctica’s permafrost – sub-surface ground whose temperature is below freezing for two years – is slowly thawing, or shrinking. Levy structured the talk as a whodunnit-style murder mystery, in which he analyzed whether conclusions from the presented research could identify the primary “culprit” of this thaw.
“You’ve all come for what you think is a lecture, but, in fact, this afternoon, there is a murder mystery that we’re going to solve,” Levy said.
Ultimately, Levy said that the best culprit was regional atmospheric warming, otherwise known as climate change. However, though most research on Antarctic thaw has studied the effects of climate change on summer temperatures, Levy said that his presentation suggests that winter warming, not summer warming, is the primary direct cause of the thaw.
“If you want to get rid of permafrost, there’s another way you can do it, and that’s wintertime warming,” Levy said. “That’s what I really want to figure out as a permafrost detective.”
Levy said that temperature weather station data for Antarctic summers in the McMurdo Dry Valleys stretching back to 1995, courtesy of the Long Term Ecological Research Network (LTER), shows that summers on the continent are not conclusively becoming much warmer, but that Antarctic winters are.
“Lucky for us, we have some witnesses [to permafrost thaw],” Levy said. “These are weather stations … which belong to the McMurdo LTER network.”
To show that summer temperatures in Antarctica have remained largely stable, Levy and student contributors analyzed data from LTER weather stations by calculating the total amount of warmth that entered the soil, called Thawing Degree Days. Levy said that though the number of warmer days during summer increased at some stations, the trend was not uniform across all locations and seemed somewhat negligible.
For winter, Levy calculated the number of freezing degree days (days where soil temperature was below zero) and graphed them. Based on this graph, Levy said that the number of freezing degree days per year has decreased over time. He said that the growing imbalance between thawing and freezing degree days means that permafrost will thaw more in the summer as a result of warmer winter temperatures.
“Across all of our sensors, we’re seeing … less freezing and more warming,” Levy said. “That’s bad – if permafrost doesn’t freeze enough during winter, it starts to thaw more in the summer.”
Levy then said that projecting the current increasing trend of wintertime warming into the future shows that all permafrost freezing in Antarctica’s McMurdo Dry Valleys could be lost by the 2130s. Following this prediction, Levy presented a few possible causes for wintertime warming – including heat caused by cloud cover and wind storms – before revealing climate change as the best explanation.
“This is like the moment in Scooby Doo when they pull the mask off of the person in the clown costume,” Levy said. “Who was behind the mask all along? Climate change.”
To explain the implications of this prediction, Levy said that there are historical parallels between modern warming and ancient climate shifts, which paint a clearer picture of Antarctica’s future.
In particular, Levy discussed the shift of spots on the banks of Lake Ontario – about two hours away from Colgate – which, 30,000 years ago, were covered in a mile-thick ice layer but have now thawed completely. A similar process, he said, is likely to occur in Antarctica over time.
“I think we should be imagining a future world that is almost unimaginable,” Levy said. “And that’s thinking about Antarctica in a world without ice, or at least a world with a vastly reduced cryosphere.”
But even though this climate change might be inevitable, Levy said, there’s no
“I don’t want to come off as pro-climate change,” Levy said. “It’s a dangerous experiment humanity is running!”
Levy also said that the thawing of Antarctica’s permafrost may, over many years, lead to a bloom of microbiology, which he called “microbial mats.” According to him, as soil conditions change, habitats suitable for microbes will expand, and microbes will ultimately foster the beginnings of a green environment in Antarctica.
“The change I’ve described for you is not the end of the world,” Levy said. “I think it’s the beginning … we’re seeing a greening of the cold desert.”
Research concerning this new phase of Antarctic conditions is Levy’s next project, for which he is soliciting student assistants.
In a closing Q&A session, Levy offered some direct advice to students considering, as he did, graduate study in an area of interest.
“No matter how much someone loves their research, by the end of five years as a graduate student working on a PhD, everyone gets tired of their project or burnt out on it,” Levy said. “So knowing what excites you most about the field or the project is something you can lean on when the going gets tough.”
First-year Michael Doyle attended the Dec. 5 talk and found Levy’s advice to students memorable.
“I also appreciated that Levy ended by urging students to pursue what interests them most, since ‘[they’ll] be bored of it in five years anyway.’”
