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Paris, September 20 (UrduPoint / Pakistan Point News, app – Sept. 21, 2018): As global warming surpasses efforts to control it, scientists have proposed to build vast underwater structures to prevent a glacier from lifting the oceans of the world of several meters.
The more modest of the two engineering projects – which is still at the scale of a Panama Canal or Suez – to strengthen the Thwaites Glacier would require the construction of columns the size of the Eiffel Tower resting on the seabed. , or ice tray.
Option two is a wall under water, up to 100 meters, or a berm, which extends 80 to 100 kilometers under the ice to block the warm bottom waters that erode the belly of the glacier, making it unstable.
The ambitious plans, detailed on Thursday in The European Geophysical Union, reflect an awareness that reducing greenhouse gas emissions, while essential, may not be done quickly enough to avoid catastrophic impacts of climate change.
"Thwaites could easily cause a collapse of the ice cap that would raise sea level by about three meters," said lead author Michael Wolovick, a researcher at the US Geophysical Fluids Dynamics Laboratory. Princeton University.
Reducing carbon pollution will not be enough either: any credible path to a world where global warming is below two degrees Celsius above pre-industrial levels (3.6 degrees Celsius), a goal enshrined in the Treaty of Paris grand amounts of CO2 out of the air.
As a result, geoengineering systems once thought to be impractical, useless or downright dangerous – injecting particles into space to deflect the sun, storing CO2 in the soil, planting millions of square kilometers in biofuels – have quickly migrated to the scientific and political discussion center.
But none of these projects tackles the rise in sea level, which can cause more human misery than any other climate impact: the end of the century
– Collapse – "The scientific community should carefully study the possibility of glacial geoengineering," said Wolovick. "There are hundreds of millions of people living a few meters from sea level.
"Until recently, the rise in sea level was mainly due to the expansion of ocean waters under the influence of global warming.Today, the biggest driver is the ice sheet located at the top of the island of Greenland and Antarctic continent.
Taken together, Greenland and West Antarctic – more vulnerable to global warming than East Antarctica – contain enough frozen water to lift the ocean's watermark by about 12 meters.
For Thwaites, there is an added sense of urgency.
"It may have already passed the tipping point, we will not know for sure for a decade or two," said co-author John Moore, chief scientist at the College of Global Change and Earth System Science at the Beijing Normal University.
"But acceleration begins slowly, so we will have a century to avoid a collapse." Wolovick and Moore developed computer models to test their geoengineering systems, taking into account known variables influencing ocean-glacier dynamics.
Underwater towers, which could be constructed from dredged materials from the continental shelf or extracted from exposed rocks, experienced a 30% change in significant decay of glacier disintegration.
– Initially skeptical – "We show that it is possible to stabilize glacier beds by providing additional anchor points that they can use to support themselves," said Mr. Moore.
Building a berm to block the hot water eating in the lower reaches of Thwaites has doubled the chances of success, but would likely be worth several hundred billion dollars.
"It's far from ready for implementation, and the potential side effects require a lot more research," Wolovick said.
The purpose of the study, he added, was mainly to spark a conversation between scientists.
"At first I was very skeptical," Moore said. "But compared to alternatives, the idea certainly deserves to be much better studied and studied." The researchers also pointed out that geoengineering solutions do not reduce the need to reduce mankind's greenhouse gas production, which reached record levels in 2017.
"There are dishonest elements in the company that will try to use our research to argue against the need to reduce emissions," Wolovick said. "Our research does not support this interpretation in any way." "The more carbon we emit, the less likely it is that the ice sheets will survive in the long term."
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