Ocean warming of up to 5 degree Celsius is likely to trigger widespread collapse of the West Antarctic ice sheet by the year 3000 as well as lift sea levels by 4 meters (13 feet), says a study.
The impact of rising carbon dioxide levels in the Earth's atmosphere will cause unstoppable effects to the climate for at least the next 1000 years, say the researchers from the University of Calgary.
The study is based on best-case, 'zero-emissions' scenarios that assume that use of all fossil fuels completely stops by 2100 and no more carbon dioxide is put into the atmosphere.
The study, which examined inertia of carbon dioxide emissions, is the first full climate model simulation to make predictions out to 1000 years from now. The research team explored zero-emissions scenarios beginning in 2010 and in 2100.
The global ocean and parts of the Southern Hemisphere have much more inertia, such that change occurs more slowly, says Professor Shawn Marshall of University of Calgary.
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Marshall says 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 in the previous century. The simulation showed that warming will continue rather than stop or reverse on the 1000-year time scale.
According to the researchers, the Northern Hemisphere fares better than the south in the computer simulations, with patterns of climate change reversing within the 1000-year timeframe in places like Canada.
At the same time parts of North Africa experience desertification as land dries out 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.
According to report from NASA, West Antarctica is seeing dramatic ice loss, culprits include the loss off buttressing ice shelves, wind, and a sub-shelf channel that allows warm water to intrude below the ice. The retreat of West Antarctica's glaciers is being accelerated by ice shelf collapse. Ice shelves are the part of a glacier that extends past the grounding line towards the ocean they are the most vulnerable to warming seas.
Researchers will next begin to investigate more deeply 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.