The polar ice sheets lost 7,560 billion tonnes of ice in between 1992 and 2020, causing a 21 mm rise in global sea levels. The latest Ice Sheet Mass Balance Intercomparison Exercise (IMBIE) reports that ice loss from Greenland and Antarctica has actually increased fivefold since the 1990s, and now accounts for a quarter of sea-level rise. The evaluation mentions that between 1992 and 2020, the polar ice sheets lost 7560 billion tonnes of ice– comparable to an ice cube determining 20 km each side. Ice loss from Greenland is responsible for almost two-thirds (13.5 mm) of this rise, and ice loss from Antarctica is responsible for the other third (7.4 mm). The polar ice sheets have together lost ice in every year of the satellite record, and the seven highest melting years have actually occurred in the last decade.
Areas in red highlight the zones of cumulative modification in ice sheet thickness in Greenland, in between 1993-2019. Credit: IMBIE/ CPOM at Northumbria University
The past decade has actually seen the worst years for polar ice sheet melting, with 2019 being the record year. Ice sheet melting now accounts for 25.6% of sea level rise, a fivefold boost because the 1990s.
The seven worst years for polar ice sheet melting have occurred throughout the previous decade, with 2019 being the worst year on record, according to a research study by IMBIE. The polar ice sheets lost 7,560 billion tonnes of ice in between 1992 and 2020, triggering a 21 mm rise in international water level. Ice sheet melting now accounts for a quarter of all sea level increase, a fivefold increase given that the 1990s. Continued ice sheet melting at the present pace might contribute in between 148 and 272 mm to worldwide mean-sea level by the end of the century.
The 7 worst years for polar ice sheets melting and losing ice have happened during the previous decade, according to new research study, with 2019 being the worst year on record.
The melting ice sheets now represent a quarter of all sea level increase– a fivefold increase since the 1990s– according to IMBIE, a global team of researchers who have actually combined 50 satellite surveys of Antarctica and Greenland taken between 1992 and 2020.
Their findings are published today (April 20) in the journal Earth System Science Data.
Worldwide heating is melting the polar ice sheets, driving up sea levels and coastal flooding around our world. Ice losses from Greenland and Antarctica can now be dependably measured from area by tracking modifications in their volume, gravitational pull, or ice flow.
NASA and the European Space Agency (ESA) granted financing to the Ice Sheet Mass Balance Intercomparison Exercise (IMBIE) in 2011 to put together the satellite record of polar ice sheet melting. Data collected by the team is extensively utilized by leading organisations, including by the Intergovernmental Panel on Climate Change (IPCC).
In their newest evaluation, the IMBIE Team– which is led by Northumbria Universitys Centre for Polar Observations and Modelling– have integrated 50 satellite studies of Antarctica and Greenland to identify their rate of ice melting.
They have found that Earths polar ice sheets lost 7,560 billion tonnes of ice in between 1992 and 2020– equivalent to an ice cube that would be 20 kilometres in height.
The polar ice sheets have actually together lost ice in every year of the satellite record, and the seven greatest melting years have actually taken place in the previous years.
Chart from IMBIE satellite information research showing the increasing contribution of ice sheets to international water level from 1992 to 2020. Credit: IMBIE/ CPOM at Northumbria University
When the ice sheets lost a shocking 612 billion tonnes of ice, the satellite records reveal that 2019 was the record melting year.
This loss was driven by an Arctic summertime heatwave, which caused record melting from Greenland peaking at 444 billion tonnes that year. Antarctica lost 168 billion tonnes of ice– the 6th highest on record– due to the continued speedup of glaciers in West Antarctica and record melting from the Antarctic Peninsula. The East Antarctic Ice Sheet remained near to a state of balance, as it has throughout the satellite period.
Melting of the polar ice sheets has caused a 21 mm increase in global sea level since 1992, almost two-thirds (13.5 mm) of which has originated from Greenland and one-third (7.4 mm) from Antarctica.
In the early 1990s, ice sheet melting represented only a little fraction (5.6 %) of water level increase. There has actually been a fivefold increase in melting since then, and they are now responsible for more than a quarter (25.6 %) of all sea level increase. If the ice sheets continue to lose mass at this speed, the IPCC predicts that they will contribute between 148 and 272 mm to international mean-sea level by the end of the century.
The most current Ice Sheet Mass Balance Intercomparison Exercise (IMBIE) reports that ice loss from Greenland and Antarctica has actually increased fivefold since the 1990s, and now accounts for a quarter of sea-level rise. The evaluation specifies that in between 1992 and 2020, the polar ice sheets lost 7560 billion tonnes of ice– equivalent to an ice cube measuring 20 km each side. The polar ice sheets have actually together lost ice in every year of the satellite record, and the seven greatest melting years have occurred in the last decade.
Professor Andrew Shepherd, Head of the Department of Geography and Environmental Sciences at Northumbria University and founder of IMBIE, said: “After a years of work we are lastly at the phase where we can continuously upgrade our evaluations of ice sheet mass balance as there suffice satellites in area monitoring them, which means that people can use our findings instantly.”
Dr. Inès Otosaka from the University of Leeds, who led the research study, stated: “Ice losses from Greenland and Antarctica have quickly increased over the satellite record and are now a significant contributor to water level increase. Continually keeping an eye on the ice sheets is important to forecast their future behaviour in a warming world and adapt for the associated dangers that seaside neighborhoods worldwide will face.”
This is now the 3rd assessment of ice loss produced by the IMBIE team, due to continued cooperation in between the area agencies and the clinical community. The first and 2nd evaluations were published in 2012 and 2018/19.
Over the previous few years, ESA and NASA have actually made a dedicated effort to launch brand-new satellite missions capable of keeping track of the polar regions. The IMBIE project has benefited from these to produce more routine updates, and, for the first time, it is now possible to chart polar ice sheet losses every year.
This third evaluation from the IMBIE Team, funded by the ESA and NASA, involved a group of 68 polar researchers from 41 international organisations utilizing measurements from 17 satellite objectives, including for the first time from the GRACE-FO gravity objective. Notably, it brings the records of ice loss from Antarctica and Greenland in line, utilizing the very same methods and covering the exact same period in time. The evaluation will now be upgraded each year to make certain that the clinical neighborhood has the extremely most current price quotes of polar ice losses.
Dr Diego Fernandez, Head of Research and Development at ESA, said: “This is another milestone in the IMBIE effort and represent an example of how researchers can collaborate efforts to evaluate the advancement of ice sheets from area offering timely and special details on the magnitude and beginning of modifications.
” The brand-new annual evaluations represent a step forward in the way IMBIE will assist to monitor these vital regions, where variations have actually reached a scale where abrupt changes can no longer be left out.”
Recommendation: “Antarctic and Greenland Ice Sheet mass balance 1992-2020 for IPCC AR6” 20 April 2023, Earth System Science Data.DOI: 10.5285/ 77B64C55-7166-4A06-9DEF-2E400398E452.
The research study, Antarctic and Greenland Ice Sheet mass balance 1992-2020 for IPCC AR6, is released in the journal Earth System Science Data, and the new dataset is openly readily available on the British Antarctic Survey website.
