In a predictive study, scientists found that 34% of the surface of all Antarctic ice shelves, measuring about half a million square kilometers, could destabilize if global temperatures were to rise by 4 degrees. About 67% of the Antarctic Peninsula ice shelf would be at risk of being destabilized in this scenario, researchers said.
Ice shelves are permanently floating ice platforms attached to parts of the coastline, formed where glaciers flowing from land meet the sea. They can help limit global sea level rise by acting like a dam and slowing the flow of melting ice and water into the oceans.
Every summer, the ice melts on the surface of ice shelves and enters smaller gaps in the snow below, where it usually freezes again. But when there is a lot of melting and little snow falling, this water instead flows onto the surface of the ice or flows into crevices. This deepens and widens the cracks, causing the plank to break and collapse into the sea.
“Ice shelves are important buffers that prevent land-based glaciers from flowing freely into the ocean and contribute to sea level rise. flow. ”, lead author Ella Gilbert, a climate scientist in the University of Reading’s Department of Meteorology, said in a statement.
Gilbert told CNN that low-lying coastal areas, especially small island states such as Vanuatu and Tuvalu, in the South Pacific, are most at risk from global sea level rise.
“Coastal areas around the world would be vulnerable, however, and countries with fewer resources available to mitigate and adapt to sea level rise will get worse,” she said.
In the new study, which used high-resolution regional climate modeling to predict the impact of increased melting and water runoff on ice shelf stability, researchers say limiting the temperature rise to 2 degrees Celsius instead of 4 degrees Celsius would cut the risk area in half. and possibly avoid significant sea level rise.
The Intergovernmental Panel on Climate Change concluded in a historic report that we only have until 2030 to drastically reduce our reliance on fossil fuels and prevent the planet from crossing the crucial 1.5 degrees Celsius (2.7 degrees Fahrenheit) threshold. above pre-industrial levels.
Global net carbon dioxide emissions should decline 45% from 2010 levels by 2030 and reach “net zero” by 2050 to keep warming around 1.5 degrees Celsius.
“The findings underscore the importance of limiting global temperature rises as outlined in the Paris Agreement if we are to avoid the worst impacts of climate change, including sea level rise,” added Gilbert.
In the Paris Accord, 197 countries agreed to the goal of keeping the Earth’s temperature “well below” 2 degrees Celsius above pre-industrial levels and making efforts to limit it to 1.5 degrees Celsius.
Gilbert told CNN that higher temperatures mean melting is more frequent and intense.
Researchers identified four ice shelves that would be threatened by a warmer climate: the Larsen C, Shackleton, Pine Island and Wilkins ice shelves, which are vulnerable due to their geographic location, and the predicted runoff in those areas.
Larsen C is the largest remaining ice shelf in the Antarctic Peninsula, and the Pine Island Glacier has received a lot of attention in recent years as it is melting rapidly in response to climate change, Gilbert said.
If these ice shelves all collapsed, which isn’t guaranteed, the glaciers that are currently holding them back would flow into the ocean, contributing to sea level rise – possibly by tens of centimeters, she explained.
The study was published Thursday in the journal Geophysical Research Letters.