(CNN) The Earth’s sheets of ice lost enough ice in the past 30 years to create an ice cube 12 miles high, according to new research.
The Greenland and Antarctic ice sheets, which contain most of the world’s freshwater ice, are shrinking at an alarmingly fast rate, according to a report on Thursday from a group of international scientists.
Combining data from 50 satellite surveys of Antarctica and Greenland, covering the years 1992 to 2020, scientists from the Ice Sheet Mass Balance Inter-comparison Exercise, or IMBIE, were able to track changes in ice volume and ice flow.
They found that ice melting has increased sixfold in the past 30 years, while record levels of planet-warming pollution have pushed up global temperatures.
The seven worst years for polar ice sheet melting have all occurred in the past decade.
The Store Glacier on the Greenland ice sheet.
In total, the polar ice sheets lost more than 8.3 trillion tons of ice between 1992 and 2020, according to the report.
The worst year for ice loss was 2019, the report found, when the surrounding ice disappeared. 675 billion tons of ice. These losses were driven by an Arctic heatwave, which saw Greenland’s ice sheet collapse by 489 billion tons.
The loss of ice has a major effect on the oceans, pushing them up sea level by 21 millimeters (less than an inch), according to the report. Melting ice now accounts for a quarter of all sea-level rise — a fivefold increase since the 1990s.
“It’s a huge amount of ice,” study lead author Inès Otosaka, a research fellow at the University of Leeds, told CNN. “This is very worrying, of course, because 40% of the world’s population lives in coastal areas,” he said.
The rate of melting in Antarctica is faster than in the 1990s.
Scientists have found that the rate of Antarctic ice melt has slowed, but remains faster than in the 1990s.
The report identified the Antarctic Peninsula and West Antarctica — the location of the turbulent Thwaites Glaciernicknamed the “Doomsday” glacier because of its destructive potential impact on sea level rise — as the regions where most of the continental melting occurs.
Otosaka expects the Greenland ice sheet to continue losing ice, but said it’s not yet clear what might happen to the Antarctic ice sheet.
“In Antarctica we have much higher uncertainty in the future,” he said. .”
That could lead to a higher sea level rise in the future, he added.
IMBIE scientists update their assessment every year.
If the world reaches certain warming thresholds, it could trigger important and potentially irreversible feedback mechanisms, Otosaka said.
“We really need to have strong government policies to limit future warming and to reduce our greenhouse gas concentration,” he added.
The European Space Agency, which along with NASA is helping to fund IMBIE’s research, said in a statement: “There is no doubt that climate change is causing the melting of our polar ice sheets, thereby driving to rising sea levels and putting coastal regions around the world at risk.”
Scientists at IMBIE plan to update the assessment every year.
“We’re finally at the stage where we can keep updating our ice sheet mass balance assessments because there are enough satellites in space monitoring them, which means people can immediately use our findings,” Andrew Shepherd, a professor at Northumbria University and founder of IMBIE, said in a statement.
