Ice sheets are time capsules of past environments, preserving samples of ancient atmospheres and chemical markers in layers of ice. Researchers drill into the ice, retrieving cylindrical cores that give them a detailed look, in chronological order, at past climates. Data from ice cores can show not only what Earth was like in prehistoric times, but how the mechanisms of climate work and how our climate may transform in the near future.
INSTAAR research scientist Tyler Jones led an effort to synthesize ideas about the most meaningful, impactful questions that researchers might answer using ice cores from Antarctica. The result, a white paper titled Paleoclimate Ice Core Research Priorities in Antarctica, lays out priorities for ice core work in Antarctica for the next five to ten years.
The white paper had its start at a meeting of the U.S. Ice Drilling Program Ice Core Working Group, a collaborative group of scientists who guide science and fieldwork for U.S. programs, involves the community in guidance decisions, and encourages collaboration. Held shortly after the start of the pandemic, the meeting occurred entirely online. “It was an open document and an open process from the very beginning,” Jones said. The meeting was open to all interested parties, and drafts were circulated widely within the ice coring community.
“The thing we all coalesced around was science that informs society.”
To prioritize the most pressing scientific questions around Antarctic ice cores, said Jones, “The thing we all coalesced around was science that informs society.”
The white paper sets out three main priorities. One centers around ice sheet stability: how much and how fast Antarctica will contribute to sea-level rise. The future of the West Antarctic Ice Sheet is a particularly important piece of the puzzle, because irreversible ice loss that leads to sea-level rise may already be underway.
Another priority is “oldest ice,” an attempt to recover a continuous record of past climate for the last million years and beyond. Investigations can compile detailed records of past temperatures, precipitation, and greenhouse gases, made possible by new technology in ice core analysis. This may allow scientists to better understand how climate can shift under different conditions, and to look for causes of the Mid-Pleistocene Transition, a time during the Pleistocene epoch when cycles of glaciation on Earth shifted from lasting 40,000 years to 100,000 years. These questions can help illuminate our own future climate.
The third priority is glacial-interglacial climate dynamics. Understanding how Earth moved between colder and warmer times in the past helps define how climate can change under natural conditions, and what happens when pressures are placed on various parts of the climate system. But very little ice is available for study in the United States that is older than the middle of the last ice age, about 65,000 years ago. New ice and new investigations will allow scientists to test hypotheses about how climate can, for example, change abruptly or undergo large-scale transitions.
The white paper also calls out the need to improve diversity and inclusion in the ice core community. Jones said, “On the one hand, if you go to an ice core field camp you might meet people from dozens of different countries. At the same time, our U.S. science programs have a diversity and inclusion issue that needs to be addressed and we focused on that.” Actions include collecting information from the community on culture and experiences, workshops and discussions during Ice Core Working Group meetings, and creating a formal reporting mechanism.
The priorities laid out in the white paper aren’t binding. But they signal to ice core researchers—and funding agencies, like the National Science Foundation—what the community considers the direction of the field and the most pressing questions it can address.
For Jones, the collaborative nature of the process was its defining feature. “Something I’ve always loved about the ice core community is the strength of the community and willingness to help each other. For me it was heartwarming to see the passion everyone loves to share around ice. But, that creates a challenge: condensing everyone’s passion into something that people are willing to read—from a document with fifty pages to ten.”