Emissions could cause sea level to rise by 40 cm by 2100, experts warn – environment

A major international study concluded Thursday that continued emissions of greenhouse gases could lead to a rise in global sea levels of about 40 cm this century as the ice sheets in Antarctica and Greenland continue to melt.

Giant ice caps contain enough frozen water to raise the ocean level by 65 meters, and researchers are increasingly concerned that their melting rates are tracking the UN’s worst-case scenarios for sea level rise.

Experts from more than thirty research institutions have used ocean temperature and salinity data to run multiple computer models that simulate potential ice loss in Greenland and Antarctic glaciers.

They tracked two climate scenarios – one where humanity continues to pollute at current levels and the other where carbon emissions are drastically reduced by the year 2100.

They found that under the high emissions scenario, the ice loss in Antarctica would see sea levels rise by 30 cm by the end of the century, with Greenland contributing an additional 9 cm.

This increase will have a devastating impact worldwide, increasing the destructive power of storm surge and exposing coastal areas of hundreds of millions of people to frequent and severe floods.

Even in a low emissions scenario, the Greenland Sheet will raise the oceans by about 3 cm by 2100 – well beyond what is already estimated to be melting due to an additional 1 ° C of warming caused by humans in the industrial age.

“It is not surprising that if we warm the planet more, more ice will be lost,” said Anders Leverman, an expert on climate and ice sheets at the Potsdam Institute for Climate Impact Research.

“If we release more carbon into the atmosphere, we will cause more ice loss in Greenland and Antarctica,” he told France Press.

“We are in our hands how quickly we allowed sea level rise and ultimately how much sea level rise.

Exceed expectations

Until the turn of the 21st century, the West Antarctic and Greenland ice sheets generally accumulated from the mass that they fell. In other words, the runoff was compensated by new snowfall.

But over the past two decades, the escalating pace of global warming has upended that balance.

Last year, Greenland lost a record 532 billion tons of ice – the equivalent of six Olympic pools of cold and fresh water flowing into the Atlantic Ocean every second. These runoff accounted for 40% of sea level rise in 2019.

The United Nations’ Intergovernmental Panel on Climate Change (IPCC) predicted in a special report on frozen areas on Earth last year that greenland snowmelt could contribute to levels of 8-27 cm in the ocean by 2100.

It was estimated that Antarctica could add 3-28 cm above that.

A study published earlier this month in Nature Climate Change stated that the mass already lost due to melting ice and aging ice between 2007-2017 is in line with IPCC’s most extreme forecast of the two pages.

They also predicted a maximum sea level rise of 40 cm by 2100.

The authors of Thursday’s paper, published in a special edition of The Cryosphere Journal, said it highlighted the role emissions this century will play in the world’s seas.

“One of the biggest uncertainties when it comes to how high sea levels are, is how much the ice sheets are contributing,” said project leader Sophie Novicki of the University of Buffalo.

“And how much the ice sheets contribute really depends on what the climate will do.”

Leverman said uncertainty in forecasts “cannot be a cause for wait and see” in emissions cuts.

“We already know something will happen. We don’t know how bad it will be.”