April 23: Exploring Antarctica’s Future and World Sea Level Rise by Ice Coring into the Past
Current ice core science reveals how Earth’s climate changes, with the oldest ice cores now reaching back 6,000,000 years. Ice cores drilled in Antarctica and the air bubbles they contain provide valuable insights into Earth’s climate history. In this session we explored how scientists are using ice core data to better understand the planet’s climate during a time of warmer temperatures and higher sea levels.
Presented by: Dr. Peter Neff, Assistant Professor of the Department of Soil, Water and Climate, University of Minnesota.
Part of the OLLI At-the-U Lecture Series.
Key Takeaways
High-Fidelity Climate Records: Antarctic ice cores provide the highest-quality records of past climate, preserved in layers of snow and trapped air bubbles. These archives allow scientists to measure atmospheric greenhouse gas concentrations — such as CO2 and methane — dating back hundreds of thousands, and in some cases millions, of years.
The Scale of Potential Sea Level Rise: The Antarctic ice sheet contains enough water to raise global sea levels by approximately 60 meters (170 feet) if fully melted. While Greenland contains only about 6 to 7 meters of sea-level equivalent, Antarctica's sheer volume makes its stability a primary global concern.
Urgency of Thwaites Glacier: A central focus of modern research is Thwaites Glacier in West Antarctica. It is considered the most concerning glacier for future sea-level rise because it is currently being melted from below by warming ocean currents. It sits in a deep inland basin, creating a potential "runaway" configuration that could lead to rapid, massive ice loss.
The Impact of Greenhouse Gases: Continuous records from deep ice cores show that for 800,000 years, CO2 levels never exceeded 300 parts per million (ppm). Today, levels have reached approximately 430 ppm due to human activities, creating an "insulating blanket" that traps heat and causes global temperatures to rise.
Gravitational Fingerprints of Melting: As ice sheets melt, they lose mass and their gravitational pull on the surrounding ocean decreases. Ironically, this means that regions furthest from the melting ice — such as North America — will experience more sea-level rise than areas closer to Antarctica.
Recent Expedition Breakthroughs: Dr. Neff co-led a US–South Korean expedition to recover a 100-year-long ice core from a remote site near Thwaites Glacier. By analyzing annual layers (such as summer peaks in hydrogen peroxide), researchers are gaining the first detailed perspective on the climate and snowfall patterns in this critical region over the last century.
Science as a Tool for Peace: US research in Antarctica is supported by the National Science Foundation and the military through Operation Deep Freeze. The Antarctic Treaty System (initiated in 1961) maintains the continent as an unclaimed territory dedicated to peaceful scientific pursuit, using science as a "currency for leadership" and global stability.
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