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Global warming – (MENAFN Gulf Times) and the resulting sea level rise have been major environmental concerns for many years. A new study, published in the journal Nature Communications, adds to concerns by revealing that Greenland’s larger glaciers could lose even more ice than previously predicted. This could have huge consequences on the global sea level rise rate.
An ice cap is a mass of glacial ice that extends over 50,000 sq km. The two ice caps on Earth today cover most of Greenland and Antarctica. Together, the Antarctic and Greenland ice sheets contain over 99% of the freshwater ice on Earth. The Antarctic ice sheet covers nearly 14 million sq km. The Antarctic ice sheet contains 30 million cubic meters of ice. The Greenland ice sheet, which spans around 1.7 million sq km, covering most of the island, is already melting rapidly and ice loss is a major contributing factor to sea level rise. . Planet-warming greenhouse gas emissions such as carbon dioxide are accelerating this merger.
But experts have less information on how these vital glaciers have changed in the past, particularly in the centuries before satellite records existed. Understanding how glaciers have responded to past climate changes can impact projections scientists make on how they may respond to future warming.
The new study has filled some of these gaps. The researchers found that Greenland’s glaciers are highly sensitive to climatic conditions and lost ice in the late 19th and early 20th centuries at rates that rival or exceed those observed today. With the planet and the Arctic in particular expected to warm much more this century, scientists warn that their findings show that Greenland ice loss could exceed even worst-case projections.
David Holland, professor of mathematics and environmental sciences at New York University and co-author of the study, said the team’s findings show that the Arctic “ is taking a punch of two in regards to the loss of its land and sea ice. covers in a warm world.
Using historical photographs of the Jakobshavn, Helheim and Kangerlussuaq glaciers, which contain enough ice to raise the global sea level by about 1.3m, the team calculated the ice loss from 1880 to 2012. They estimated that the amount of ice lost from these three glaciers alone both result in an 8.1 mm sea level rise. Holland said that while the three glaciers are important in their own right, they also act as a proxy for most of the other outlet glaciers in Greenland, giving scientists an idea of how the entire ice sheet, which is constantly in movement. If the interior of the ice sheet is regarded as a mountain lake, these outlet glaciers are the streams that fan out of the lake, carrying the ice away from it and, in many cases, into the ocean. When the ice breaks off the glacier and lands in the ocean, the sea level rises.
Ice loss over time is determined by natural changes in ocean winds and currents, and as warm waters approach glaciers, they melt. But human-caused warming has altered the climate and is changing the way winds and the ocean interact with the ice sheet, thereby affecting the amount of ice loss.
Sea rise is already causing problems in many low-lying coastal areas. And for places like New York and Shanghai, 1m or more of sea level rise could spell disaster. Another recent study found that rising seas could cost the global economy $ 14.2 trillion in lost or damaged goods by the end of the century and expose up to 287 million people to episodic flooding, up from 171 million. of today.
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