By Fern Alling,
Medill News Servicer, Dec. 17, 2024
Just as “those who cannot remember the past are condemned to repeat it,” those who understand the past are better able to weather the future. The first warning comes from philosopher George Santayana. The second explains the importance of the annual Comer Climate Conference.
Researchers from various disciplines gathered in southwestern Wisconsin again this year to attend the conference. Each scientist has a chance to present their work to the group formally in research presentations and informally at social gatherings. This open exchange of scientific knowledge spurs further work that can equip decision-makers with tools to respond to modern climate disruption.
Many scientists at the conference focus on paleoclimatology, or the scientific study of past climates. They rely heavily on proxies for glimpses into the past, meaning data present in the historical record that can be used to estimate things that aren’t directly preserved, like timespans or the pace of change.
Matt Lacerra, a geochemistry Ph.D. candidate at Princeton University, is investigating oxygen levels in the ancient Pacific Ocean. The eastern tropical Pacific has large patches of ocean that contain so little oxygen they are considered dead zones for marine life. Understanding how the Pacific’s dead zones behaved as the planet cooled and warmed in the past helps Lacerra and others predict how global warming might affect modern dead zones. The findings are particularly relevant to the many fishing communities that depend on the eastern tropical Pacific for their livelihood.
Lacerra and his team are using foraminifer fossils from a sediment core as a proxy for past ocean oxygen. Foraminifers are single-celled organisms with a 500-million-year fossil record. They grow a hard external shell from minerals in the seawater. When there isn’t enough oxygen in the water for foraminifers to breathe, some can switch to breathing nitrogen. By measuring the nitrogen present in the foraminifers’ fossils, Lacerra’s team can estimate oxygen levels in prehistoric times.
Different proxies can help researchers approach similar subjects from different angles. Guleed Ali is studying ice sheets on land rather than ocean ice or the ocean itself, but the two areas are closely connected.
Ali, an IDEA fellow with the Stony Brook University department of geosciences, is mapping how a massive ice sheet expanded thousands of years ago. Ice sheets are large, glacier-like formations that can span continents. As they melt, they release cold, fresh water into the ocean that disrupts heat-circulating global currents. This disruption can trigger a cascade of climate effects, so understanding when and why an ice sheet’s size changed is essential to understanding the relationships between different climate systems.
Ali is using fossilized trees as a proxy for the movement of the Cordilleran ice sheet. The Cordilleran ice sheet was roughly the size of Greenland during the last ice age and covered a portion of the North American West Coast. As it expanded, the ice sheet knocked down trees that later became preserved in rocks. By radiocarbon dating the fossilized trees, Ali can use them as markers for where the ice sheet moved and when.
Time is of the essence in this work. Nailing down the particulars of past climate patterns is vital to predicting how dead zones and ice sheets will behave in the future.
“The imperative to get more data and test these ideas has just never been higher,” said Richard Alley, a geosciences professor at Penn State University and long-time attendee at the conference.
But time is also the essence of what makes the conference special. Multiple presentations typically run at the same time in larger conferences, and attendees must sometimes sprint from one room to the next in order to catch them. By contrast, the Comer conference’s intimate size allows the scientists to participate in each presentation without the extra cardio.
The Comer conference also offers ample opportunities for researchers to connect. If a scientist’s ideas are intriguing to you, “you can go have lunch with them, or breakfast, and chat some more,” said Tricia Collins, a climate science Ph.D. student with the University of Maine. “This just is a nice pace.”
The conference allows researchers to trade ideas, learn about new proxies and network. Together, they can slow down and unravel the past so we can better respond to a rapidly changing future.
Photo at top: The Comer Conference gives participants lots of opportunities to connect over lunch on a hilltop, hikes through conference area trails, session breaks and social hours. (Fern Alling/Medill News Service)
