Summit County Citizens Voice

Global warming is just getting started in the Antarctic region.

West Antarctic ice sheet likely to collapse; sea level to rise 15 feet

By Summit Voice

SUMMIT COUNTY — Even if CO2 emissions were to cease completely by 2010, the climate change already under way would continue for at least 1,000 years, according to new study done by researchers at the Canadian Centre for Climate Modelling and Analysis (an Environment Canada research lab at the University of Victoria) and the University of Calgary.

Continued warming will probably collapse the Antarctic ice sheet and lead to sea level rise of almost 15 feet, the scientists theorized in a paper published Jan. 9 in the journal Nature Geoscience. The study is being touted as the first full climate model simulation to make predictions out to 1,000 years from now.

“We created ‘what if’ scenarios,” says Dr. Shawn Marshall, Canada Research Chair in Climate Change and University of Calgary geography professor. “What if we completely stopped using fossil fuels and put no more CO2 in the atmosphere? How long would it then take to reverse current climate change trends and will things first become worse?”

The research team explored zero-emissions scenarios beginning in 2010 and in 2100.

The Northern Hemisphere fares better than the south in the computer simulations, with patterns of climate change reversing within the 1,000-year timeframe in places like Canada.

At the same time North African deserts could grow by up to 30 percent, and ocean warming of up to 5 degrees celsius off of Antarctica is likely to trigger widespread collapse of the West Antarctic ice sheet, a region the size of the Canadian prairies.

Researchers hypothesized that one reason for the variability between the North and South is the slow movement of ocean water from the North Atlantic into the South Atlantic.

“The global ocean and parts of the Southern Hemisphere have much more inertia, such that change occurs more slowly,” said Marshall. “The inertia in intermediate and deep ocean currents driving into the Southern Atlantic means those oceans are only now beginning to warm as a result of CO2 emissions from the last century. The simulation showed that warming will continue rather than stop or reverse on the 1000-year time scale.”

Wind currents in the Southern Hemisphere may also have an impact. Marshall said that winds in the global south tend to strengthen and stay strong without reversing.

“This increases the mixing in the ocean, bringing more heat from the atmosphere down and warming the ocean,” he said.

Researchers will next begin to investigate the impact of atmosphere temperature on ocean temperature to help determine the rate at which West Antarctica could destabilize and how long it may take to fully collapse into the water.

Filed under: climate and weather, Environment, global warming, Summit County news Tagged: | climate change, Environment, global warming, sea level rise, Summit County Colorado, Summit County News, University of Calgary, West Antarctic Ice Sheet