AMHERST, Mass. – One of the world’s leading Antarctic climate researchers, geoscientist Rob DeConto of the University of Massachusetts Amherst, will present the high-profile S.T. Lee Lecture in Antarctic Studies on Sept. 3 at Victoria University, Wellington, New Zealand. It is titled, “The fate of the Antarctic ice sheet: Lessons from the geological past and how they are informing future predictions.”
DeConto’s lecture will discuss how melting of the Antarctic Ice Sheet now poses the single greatest threat to shorelines and coastal cities globally, because it is estimated to contain more than 160 feet (50 meters) of equivalent sea level. That is the change in global average sea level that would occur if that amount of water or ice were added to the oceans. He will discuss what geological records tell us about the past history of the ice sheet, attempts to develop numerical models to simulate those past changes, and what the models say about the ice sheet’s long-term future over coming decades and centuries.
Acknowledging that past S.T. Lee lecturers have been some of the most highly regarded scholars in Antarctic climate studies since the series began in 2003, DeConto says, “It’s a great honor to be invited to give this talk and to stand in this kind of company.”
Regarding recent Antarctic climate models, DeConto points out that, “Emerging geological records imply surprising sensitivity of the ice sheet, with serious implications for its future response to climate and ocean warming. Recent observations show accelerating retreat of some major outlet glaciers, especially in West Antarctica where the bed of the ice sheet lies hundreds of meters below sea level, hinting that a massive runaway ice retreat is already underway.”
On Aug. 27, DeConto presented preliminary findings of his study of Antarctica’s potential for past and future contributions to sea level rise at a meeting of the Scientific Committee on Antarctic Research (SCAR) in Auckland. The UMass Amherst geoscientist was recently elected as one of 70 new members from among more than 400 candidates worldwide to SCAR’s “Horizon Scanning Group.” These experts, who are planning the next 20 years of Antarctic research, this month published a comment, “Polar research: Six priorities for Antarctic science,” in Nature.
He says that new models suggest global sea level rise, in particular in the Northern Hemisphere, will be much higher than anyone has predicted to date. DeConto and colleagues’ simulation of past and future sea level conditions show that warmer ocean temperatures accelerate ice sheet calving, and melting Antarctic ice sheets in particular will have a disproportionately large effect on sea level rise in the Northern Hemisphere.
“Antarctica is shown to contribute up to 35 feet (10 m) of sea level rise within the next five centuries. Given current rates of Southern Ocean heat uptake, these results have serious implications for future commitment to sea level rise, regardless of future greenhouse gas emissions,” the researchers report.
DeConto says, “Through this work we have a better idea what to expect in the future. We’ve had a relatively long period of not having to deal with retreat of the huge Antarctic and Greenland ice sheets. Predictions are that we should be sliding into another ice age, but we may be preventing that with the CO2 that we’re putting into the atmosphere. We are altering both short term and long-term future climate.”
Seng Tee Lee, a Singapore businessman and philanthropist, endowed several lecture series at institutions around the world including Oxford, Cambridge and Harvard, to provide a platform for prominent scholars not only in Antarctic and Arctic research, but also in public policy, military history and other topics.