WHAT’S BEING CLAIMED:
- Greenland, home to the world’s second largest ice sheet, is losing ice at an increasingly rapid pace – about six times faster than in the 1980s.
- Its glaciers alone have reportedly caused sea levels to rise by half an inch since 1972.
- Experts warned that if the entire Greenland Ice Sheet melted, the sea level would rise about 20 feet.
Researchers estimate that Greenland’s glaciers are melting six times faster than it was in the 1980s, causing the sea level to rise by 13.7 millimeters (0.5 inches) since 1972.
According to experts, half of the sea level rise has occurred in the past eight years, and it’s likely to get worse with global warming.
Greenland is home to the Earth’s second-largest ice sheet – with its glaciers melting faster, more icebergs break off into the ocean.
Experts estimate that the amount of ice moving into the ocean had increased from 51 billion tons (46 bn tonnes) between 1980-1990 to a staggering 286 billion tons (259 bn tonnes) between 2010-2018.
Satellites, weather stations, and sophisticated climate models have enabled today’s researchers to accurately measure the amount of melting ice.
The team used three methods of measurement:
The first method used satellites to measure altitude with a laser. If a glacier has melted, the satellite would record its reduced height.
The second method measured variations in gravity. A decrease in gravitational pull indicated ice loss.
The third method used mass balance models. The accumulated mass (rain and snow) was compared with the lost mass (ice river discharges) to calculate the remaining ice mass.
These methods helped the team recalculate the amount of ice loss and reconstruct Greenland’s ice levels in the 1970s and 1980s.
The data collected from before the 1990s, however, is limited and unreliable due to less advanced technology.
The team discovered that Greenland accumulated 47 gigatonnes (51 tons) of ice per year during the 1970s but lost an equivalent volume in the 1980s.
The study found a maintained rate of melting in the 1990s, until it sharply increased in the 2000s, and even more since 2010.
Glaciologist Professor Eric Rignot from the University of California professed, “It is a bit scary to see how fast it is changing.”
The researchers noted that if the entire Greenland Ice Sheet melted, the sea level would rise about 20 feet (6 meters).
Around 40 to 50 percent of the world’s population resides in cities vulnerable to rises in sea level. The drastic increase in sea level would expose coastlines to greater risks of flooding, erosion, and storm hazards.
The complete study was first published in Proceedings of the National Academy of Sciences on April 22, 2019.
Source: Daily Mail