Sea level rise from ice sheets track worst-case climate change scenario: Phys.org

Credit: CC0 Public Domain 

Ice sheets in Greenland and Antarctica whose melting rates are rapidly increasing have raised the global sea level by 1.8cm since the 1990s, and are matching the Intergovernmental Panel on Climate Change's worst-case climate warming scenarios.

According to a new study from the University of Leeds and the Danish Meteorological Institute, if these rates continue, the ice sheets are expected to raise sea levels by a further 17cm and expose an additional 16 million people to annual coastal flooding by the end of the century.

Since the ice sheets were first monitored by satellite in the 1990s, melting from Antarctica has pushed global sea levels up by 7.2mm, while Greenland has contributed 10.6mm. And the latest measurements show that the world's oceans are now rising by 4mm each year.

"Although we anticipated the ice sheets would lose increasing amounts of ice in response to the warming of the oceans and atmosphere, the rate at which they are melting has accelerated faster than we could have imagined," said Dr. Tom Slater, lead author of the study and climate researcher at the Centre for Polar Observation and Modelling at the University of Leeds.

"The melting is overtaking the climate models we use to guide us, and we are in danger of being unprepared for the risks posed by sea level rise."

Greenland's melting ice sheet has passed the point of no return, scientists say (excerpt): USA Today

STORY HIGHLIGHTS

• Greenland's ice sheet dumps more than 280 billion metric tons

Even if global warming were to stop today, the ice sheet would continue shrinking.

of melting ice into the ocean each year.
 
•  Even if global warming were to stop today, the ice sheet would continue shrinking.
• Scientists analyzed 40 years of satellite data from more than 200 large glaciers draining into the ocean.

Greenland's melting ice sheet has passed the point of no return. 

In fact, glaciers on the island have shrunk so much that even if global warming were to stop today, the ice sheet would continue shrinking, a new study suggests.

"Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss," study co-author Ian Howat, an earth scientist from Ohio State University, said in a statement. "Even if the climate were to stay the same or even get a little colder, the ice sheet would still be losing mass."

This "tipping point" means the snowfall that replenishes the ice sheet each year cannot keep up with the ice that is flowing into the ocean from melting glaciers.

Doyle Rice

USA TODAY

Updated August 18, 2020 

 

Read the original story 

 

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