Global sea levels set to rise higher than previously predicted — research
Experts predict potential 2-meter rise by 2100 and 5 meters by 2150, if global warming gas emissions continue to climb
Sue Surkes is The Times of Israel's environment reporter.
Mean global sea levels could rise by half a meter (1.6 feet) by 2050, two meters (6.6 feet) by 2100 and five meters (16.4 feet) by 2150 if global warming gas emissions continue to rise throughout the century, according to new research on the impact of polar ice cap melting.
This is much higher than United Nations experts have predicted to date, Pam Pearson, founder and director of the International Cryosphere Climate Initiative (ICCI) told an open meeting of the Environmental Protection Ministry’s Climate Preparedness Directorate in Tel Aviv.
Last year, the UN’s Intergovernmental Panel on Climate Change (IPCC) predicted that by 2100, the global mean sea level will likely have risen half a meter to a meter higher in the span of two centuries, depending on different emissions scenarios.
But ICCI has now added a new forecast, the fruits of research carried out since last year, in which scientists were able to integrate known sea levels from Earth’s history with observations of glacial melting over recent decades, and future projections under various scenarios of emissions and temperature increases.
The Environmental Protection Ministry’s chief scientist, Noga Kronfeld-Schor, will soon update government bodies about the new figures to aid long-term planning.
On Tuesday, Haaretz reported that information received from more than 20 sources in government bodies, local authorities and scientists indicated potential risks from rising sea levels to Israeli coastal desalination facilities, cliffs, drainage infrastructure and even defense facilities close to the sea.
Israel has no single body or budget dedicated to the issue of sea levels, the paper noted. Instead, the issue is one of many dealt with by the Climate Preparedness Directorate.
“A lot of the ice sheet melting is thought to be irreversible,” Pearson told the Environmental Protection Ministry’s confab, held at the Steinhardt Natural History Museums, by video link from the US.
Policymakers still do not fathom the serious global ramifications of polar ice melting, Pearson said. Now, she said, scientists are trying to make the world aware that the melting of the cryosphere (where water is locked up as ice) would affect global systems, “including coastlines that are irreversible, on human timescales.”
“We’re in unchartered territory because we haven’t seen such a rapid rise in carbon dioxide emissions, in temperatures, in Earth’s history,” Pearson said, presenting images of parts of Israel and Egypt under different sea level scenarios.
The scenarios, culled from an interactive site run by Climate Central, showed much of the coast abutting the Haifa Bay in northern Israel submerged under water in the wake of a two-meter sea level rise. Much of the popular Dor and Nahsholim beaches on the northern central coast would be submerged, as well as parts of the Nitzanim and Zikim beaches in the south.
Should the global temperature rise 3° Celsius (37.4° Fahrenheit) — and current climate policies have predicted a 3.1°C (37.6° Fahrenheit) temperature increase — sharp and unstoppable rises in sea levels would kickstart from 2060, Pearson explained.
A rise of three meters, the Climate Central website shows, would see seawater almost reaching Nesher, a city in the Haifa District.
It would also bury Alexandria and much of the Nile Delta in Egypt.
Humanity’s ability to halt this trend would depend on serious success not only in reducing emissions but also in removing carbon dioxide from the atmosphere.
The latter is currently happening on a small scale, and carbon absorption technology — known as carbon sequestration — is only in its infancy.
Furthermore, current emissions are still rising. “We are still following what scientists call the very high emissions levels that would lead to some of these extreme sea levels,” Pearson said.
Planners must also consider storm surges which bring abnormal increases of water toward the shore, Pearson went on.
The Israel Oceanographic and Limnological Research Institute, which has been monitoring sea levels since 1992, has registered an average increase of 4.6 millimeters (0.18 inches) per year — compared with a global figure of 3.25 millimeters (0.13 inches) — adding up to a 13.8 centimeter (5.4 inch) total.
Alon Zask, the institute’s director, who until recently also managed the Climate Preparedness Directorate, told Haaretz that for future forecasts, his staff relied on international calculations, because they do not have the computation ability necessary.
The new international data will be integrated into a climate risk map that the Environmental Protection Ministry is currently developing.