This boring horror story comes from the Department of We've All Heard It Before and the Department of Unverifiable Predictive Models at Dartmouth College.
Dartmouth-led study compiles 16 models to accurately predict ice loss up to 2,300 years
A Dartmouth College-led study involving more than 50 climate scientists from around the world provides the first clear prediction of how carbon emissions could cause most of Antarctica's ice sheet to disappear over the next 300 years.
The future of Antarctica's glaciers becomes uncertain after 2100 when existing ice sheet models are looked at alone, researchers report in the journal Earth's future. They combined data from 16 ice sheet models and found that overall, predictions agree that ice loss from Antarctica will increase gradually throughout the 21st century, even under current carbon emissions.
But the researchers found that this consistency dropped sharply after 2100. Models predict that under current emissions, ice will begin to retreat rapidly across much of the West Antarctic basin. Melting glaciers could raise global sea levels by 5.5 feet by 2200. Some of the team's numerical experiments predict that the West Antarctic Ice Sheet will almost completely collapse by 2300.
“When you talk to policymakers and stakeholders about sea level rise, their main focus is on what will happen by 2100. There is very little research beyond that,” said Dartmouth's first author on the study. Hélène Seroussi, associate professor at the Seiller Institute, said.
“Our study provides long-term predictions that have been lacking,” she said. “The results suggest that long-term impacts will become greater after 2100 in areas most vulnerable to sea level rise.”
Mathieu Morlighem, a professor of earth sciences at Dartmouth University and co-author of the study, said the researchers simulated changes in the Antarctic ice sheet in the year 2300 under high- and low-emission scenarios. Dartmouth Engineering alumnus Jake Twarog '24 is also a co-author of the study and contributed as an undergraduate.
“While current carbon emissions have little impact on model projections this century, the difference between the impact of high- and low-emission scenarios on sea level rise widens dramatically after 2100,” Morlighem said. “These results confirm that Reducing carbon emissions now is critical to protecting future generations.”
The timing at which Antarctica's glaciers begin to retreat varies depending on the ice flow model researchers use, Serousi said. However, once the ice begins to lose rapidly, the rate at which large-scale retreat occurs is consistent across models.
“All models agree that once these major changes begin, nothing can stop or slow them down. Several basins in West Antarctica may experience complete collapse by 2200,” Seroussi said. “The exact timing of this collapse remains unknown and depends on future greenhouse gas emissions, so we need to react quickly enough to reduce emissions before major basins disappear.”
Seloussi said the research could lead to further collaborative models that scientists can use to understand and resolve differences in predictions in areas with significant model uncertainties or the Greenland ice sheet. Research and computational resources can then be focused on investigating the outcomes these multiple models are most likely to predict.
“We're asking the scientific community to find out what's going to happen,” Seloussi said. “This collaboration means we have a better, more robust assessment of uncertainty and we can see where our models agree and where they disagree, so we know where to focus future research.”
###
paper:
The Future of Earth, DOI 10.1029/2024EF004561
Relevant
