New research, published today in the journal Climate change in nature, he said Antarctic icebergs could weaken and delay global warming in the southern hemisphere.
Unnamed global warming threatens the stability of the Antarctic ice sheet. Recent observations reveal the rapid thinning of Pine Island and Thwaites in Antarctica, which can be partly attributed to ocean warming. These findings raised concerns about the accelerated loss of ice in West Antarctica's ice cover and the potential contribution to global sea-level rise. Ice loss can occur in the form of an alloy-induced (liquid) discharge of fresh water into the ocean or through (permanent) calving of the iceberg.
With the planned reverse of the Antarctic ice cover, scientists expect an increase in iceberg discharge. Icebergs can persist for years and are carried by winds and currents across the Southern Ocean until they reach warmer waters and eventually melt. The melting process cools the ocean water like ice cubes in a cocktail glass. In addition, freshwater discharge from icebergs affects currents by reducing oceans salinity. Whether this "iceberg effect" can slow down or change future climate change in the southern hemisphere remains an open question.
Climate researchers from the University of Hawaii (USA), IBS Center for Climate Physics (South Korea), Penn State University (USA) and the University of Massachusetts (USA) for the first time determined this effect of Antarctic iceberg calving on the future Southern Hemisphere climate. The team conducted a series of computer simulations of global warming that include the combined effects of fresh water and iceberg cooling on the ocean. The size and number of icebergs released in their model mimics the gradual withdrawal of Antarctica's ice cover over several hundred years. By incorporating the "iceberg effect" in their climate model, scientists have found that icebergs can significantly slow down man-made warming in the southern hemisphere, affecting winds and precipitation patterns around the world.
"Our results show that the impact of Antarctic and iceberg melting should be included in computer simulations of future climate change. Climate models currently used in the Sixth Assessment of the Intergovernmental Panel on Climate Change (IPCC) do not include this process. "- says Dr. Fabian Schloesser, the main author of the study in Climate change in nature.
Dr. Tobias Friedrich, co-author of the study, adds: "The melting of icebergs released in the 21st century in one of our extreme withdrawal scenarios in Antarctica would require 400 times the current annual energy consumption in the world. The global sea level will rise by about 80 cm, which will affect many coastal regions and communities around the world. "
Recent studies suggest that the impact of the discharge of Antarctic seawater on the ocean may lead to further acceleration of ice sheet melting and global sea level rise. This study presents a more complex picture of basic dynamics. Considering the cooling effect of icebergs, it largely compensates for processes that were previously thought to accelerate the melting of Antarctica.
"Our research highlights the role of icebergs in global climate change and rising sea levels. Depending on the decay rate of the West Antarctic ice cover, the iceberg effect may delay future warming in cities such as Buenos Aires and Cape Town by 10-50 years, "says prof. Axel Timmermann, research author and director of the IBS Climate Physics Center.
The research team plans to more accurately determine the relationship between ice and climate and its impact on global sea level using a new computer model they have developed.
Institute of Basic Science. .