0

Ice melt projections may underestimate Antarctic contribution to sea level rise

Posted on

Ice melt projections may underestimate Antarctic contribution to sea level rise
Thwaites Glacier, Antarctica, pictured in 2019. Credit: NASA

Fluctuations in the weather can have a significant impact on melting Antarctic ice, and models that do not include this factor can underestimate the global impact of sea level rise, according to Penn State scientists.


“We know ice sheets are melting as global temperatures increase, but uncertainties remain about how much and how fast that will happen,” said Chris Forest, professor of climate dynamics at Penn State. “Our findings shed new light on one area of uncertainty, suggesting climate variability has a significant impact on melting ice sheets and sea level rise.”

While it is understood that continued warming may cause rapid ice loss, models that predict how Antarctica will respond to climate change have not included the potential impacts of internal climate variability, like yearly and decadal fluctuations in the climate, the team of scientists said.

Accounting for climate variability caused models to predict an additional 2.7 to 4.3 inches—7 to 11 centimeters—of sea level rise by 2100, the scientists recently reported in the journal Climate Dynamics. The models projected roughly 10.6 to 14.9 inches—27 to 38 centimeters—of sea level rise during that same period without climate variability.

“That increase alone is comparable to the amount of sea level rise we have seen over the last few decades,” said Forest, who has appointments in the departments of meteorology and atmospheric science and geosciences. “Every bit adds on to the storm surge, which we expect to see during hurricanes and other severe weather events, and the results can be devastating.”

The Antarctic ice sheet is a complex system, and modeling how it will evolve under future climate conditions requires thousands of simulations and large amounts of computing power. Because of this, modelers test how the ice will respond using a mean

0

Rising Temperature Could Melt Antarctica ‘Irreversibly’, Warns New Study

Posted on

KEY POINTS

  • Researchers say melting Antarctic ice could raise sea level by 8 feet
  • Such a rise in sea levels would devastate coastal cities and cultural sites around the world
  • Study says the only solution is to bring the world’s temperature back to pre-industrial levels

Coastal cities and cultural sites around the world could soon be submerged in water if the melting of ice in Antarctica reaches an “irreversible” level. If global warming is allowed to continue unchecked, most of Antarctica will be gone forever, a new study warns.  

The melting of ice in Antarctica can make glaciers the size of Florida slide into the ocean, said Anders Levermann, a researcher at the Potsdam Institute for Climate Impact Research in Germany, and a co-author of the study. The team ran computer simulations to identify “where exactly and at which warming levels the ice in Antarctica would melt.”  

“We find that already at 2 degrees of warming, melting and the accelerated ice flow into the ocean will, eventually, entail 2.5 meters (8 feet) of a global sea-level rise just from Antarctica alone. At 4 degrees, it will be 6.5 meters (21 feet) and at 6 degrees almost 12 meters (39 feet) if these temperature levels would be sustained long enough,” Levermann said in a press release. 

The cultural sites in danger of being submerged include the Copacabana Beach in Brazil’s Rio de Janeiro and Sydney’s Opera House. Cities including London, New York City, Tokyo, Mumbai in India, and Hamburg, Germany, are also at risk, the researchers say.

Antarctica holds more than 50% of fresh water on Earth, Ricarda Winkelmann, a researcher at the Potsdam Institute for Climate Impact Research, said in the press release. Human activities, most particularly greenhouse-gas emissions, heat the ocean water and atmosphere. This leads to the melting