CALGARY, Canada (Reuters) – The carbon dioxide already emitted into the atmosphere will continue to contribute to global warming for centuries, eventually leading to the collapse of a huge expanse of Antarctic ice and rising sea levels , Canadian scientists said on Sunday.

Even completely abandoning the use of fossil fuels and reducing emissions cannot prevent disastrous warming of Antarctic waters and increased desertification in North Africa, the researchers said.

Even so, many of the negative consequences in the northern hemisphere, such as the loss of Arctic ice, are reversible.

This means that global efforts to reduce greenhouse gas emissions are not a waste of work and money, said Shawn Marshall, professor of geography at the University of Calgary and one of the authors of the ‘study.

“Although there are some parts of the climate that have a lot of momentum and it will be several centuries before it starts to reverse,” Marshall said.

The study, led by Nathan Gillett of the Canadian Center for Climate Modeling and Analysis, was published in the journal Nature Geoscience.

Using simulations with a weather model, scientists estimated the effects on weather conditions over the next 1,000 years by stopping emissions completely in 2010 and 2100.

Large differences in impacts in various regions would persist over the centuries needed to circulate heat from the North Atlantic through ocean currents and deep oceans around the world, Marshall said.

“The atmosphere cools fairly quickly as atmospheric gases drop and surface water cools, but that won’t reach the deepest ocean waters for a long time,” he said.

Air currents in the southern hemisphere can also play a role.

As a result, over the next 1,000 years, the average ocean temperature around Antarctica could rise by up to 5 degrees Celsius, causing the ice caps west of the white continent to collapse, according to the study.

The removal of the ice, which covers an area roughly the size of Texas and 4,000 meters thick, could raise sea levels by several meters.