He thawing of icy layers Greenland and Antarctica could raise global sea level by 38 centimeters by the end of this century if greenhouse gas emissions are not curbed.
This follows from a study conducted by more than 60 scientists from three dozen international institutions and led by NASA’s Goddard Space Flight Center. The work is published in the magazine Cryosphere.
This result is in line with the projections of the special report on the oceans and cryosphere made public last year by the Intergovernmental Panel on Climate Change (IPCC).
Water from thawing the frozen layers of the Earth contributes approximately a third of the total rise in sea level in the world. The IPCC report projected that Greenland would contribute 8 to 27 centimeters to global sea level rise this century and that Antarctica could contribute between 3 to 28 centimeters.
“One of the biggest uncertainties when it comes to how much sea level will rise in the future is how much ice sheets will contribute“says Sophie Nowicki, now at the University at Buffalo (USA) and previously at NASA’s Goddard Space Flight Center.” The contribution of the ice sheets it really depends on what the weather will do“.
The Greenland ice sheet contributes significantly the rise in sea level with the increase in air temperatures that melt the surface of the ice sheet and the increase in ocean temperatures that cause the retreat of the glaciers that end in the oceans.
Scientists investigated two different scenarios that the IPCC has established for future climate in order to predict sea level rise between 2015 and 2100: one with increased greenhouse gas emissions and the other with lower emissions.
In the high emissions scenario, found that the Greenland ice sheet would contribute an additional 9 cm global sea level rise in 2100; in the lowest emissions scenario, the loss of that ice sheet would raise global sea level by three centimeters.
Additionally, the researchers also analyzed the Antarctic Ice Sheet to understand how much ice melted for future climate change would add to sea level rise.
In this case it’s harder to predict– In the west, warm ocean currents erode the bottom of large floating ice shelves, while the vast ice sheet of East Antarctica can gain mass, Since the warmer temperatures cause more snowfall.
The results point to a greater range of possibilities, from a change in the ice sheet that sea level decreases by 7.8 centimeters until increase it by 30 centimeters by the end of the century, with different climatic scenarios. Regional projections show the largest loss in West Antarctica, responsible for up to 18 centimeters of sea level rise by 2100 in warmer conditions, the research found.
“The Amundsen Sea region in West Antarctica and Wilkes Land in East Antarctica are the two most sensitive regions warming ocean temperatures and changing currents and will continue to lose large amounts of ice“, stresses Hélène Seroussi, a scientist at NASA’s Jet Propulsion Laboratory.