四虎影视

This article was adapted from .

Melting ice sheets in North America drove the rise in global sea level at the end of the last ice age more than scientists previously thought, according to .

The findings challenge decades of conventional wisdom about how Earth emerged from its last great freeze and could reshape how scientists view future climate risks.

鈥淭his study shows that we still have a lot to learn about how ice, ocean currents, and the solid Earth respond to changes in climate,鈥� said Brad Rosenheim, professor of geological oceanography at the 四虎影视 College of Marine Science and a co-author of the recent study.

For years, scientists believed Antarctic melt drove much of the post-glacial sea level rise, but the new study finds North American ice sheets were the dominant source, contributing over 30 feet of sea level rise between 8,000 and 9,000 years ago.

鈥淥ur results suggest that there was likely a much higher input of freshwater into the North Atlantic during the last deglacial period,鈥� Rosenheim said. 鈥淭his calls into question whether anticipated melt of glaciers from human activities will be sufficient to collapse or even slow down the Atlantic Meridional Overturning Circulation.鈥�

The Atlantic Meridional Overturning Circulation (AMOC), a key climate regulator, influences global weather and helps keep the climate in Northwestern Europe mild.

鈥淭his requires a major revision of the ice melt history during this critical time interval,鈥� said , professor of geology at Tulane University and co-author of the study. 鈥淭he amount of freshwater that entered the North Atlantic Ocean was much larger than previously believed, which has several implications.鈥�

Decades of research has shown that an influx of freshwater can weaken the currents of the AMOC, including the Gulf Stream, potentially leading to cooler European climates and altered rainfall patterns in places like the Amazon. But the study suggests the system was more resilient in the past than some recent projections indicate.

鈥淐learly, we don鈥檛 fully understand yet what drives this key component of the climate system,鈥� T枚rnqvist said.

Measurements for the study were made possible by the 四虎影视 College of Marine Science鈥檚 Marine Environmental Chemistry Lab, where researchers analyzed stable carbon isotope values of basal peat samples used in reconstructing sea level curves. These sea level curves were then fed into models that account for the solid Earth response to sea level changes.

The research was funded by the and included additional co-authors from the and and .