If the trend continues, there is a risk of a critical rise in sea levels, which could lead to the flooding of parts of island nations and affect the coastal infrastructure of many countries, reports correspondent Kazpravda.kz citing Naked-Science.
Moreover, this serves as an indicator of human contributions to climate change. This is why monitoring glacial mass loss is crucial. However, doing so is challenging due to data gaps and their heterogeneity. The authors of the new study have navigated these limitations as much as possible by collaborating with regional research groups.
According to estimates, in the year 2000, the area of glaciers covering the Earth, excluding the large continental ice sheets of Greenland and Antarctica, was 706,000 square kilometers, with a volume of just over 158,000 cubic kilometers. If all this mass were to melt, sea levels would rise by 324 millimeters.
Glaciologists monitor the situation not only through expeditions, as direct observations can cover no more than 1% of glaciers. Remote sensing methods from satellites provide geodetic, gravimetric, and altimetric data. Digital Elevation Models (DEM) also play a significant role. Together, these tools offer a rough picture of changes in ice mass on the planet over time, while simultaneously complicating the analysis of heterogeneous data.
Researchers from the GlaMBIE collaboration have combined results from various observations and calculated the rate of ice loss on the planet, excluding Greenland and Antarctica. An article on this was published in the journal Nature.
The authors analyzed 233 estimates of glacier mass change across 19 regions. Data were obtained from 35 research groups, bringing together approximately 450 participants. The study covered the period from 2000 to 2023.
During this time, glaciers lost 6.5 gigatonnes of mass, contributing an additional 18 millimeters to sea levels. The melting rate from 2012 to 2023 increased by 36% compared to 2000-2011. The last five-year period marked the largest loss of ice, with an annual decrease of 400 gigatonnes, including a record loss in 2023 of 548 gigatonnes.
When compared to ice sheets, the losses of all other glaciers over the decade from 2002 to 2021 were 18% greater than those of Greenland and twice the losses of Antarctica.
All 19 regions examined in the study experienced glacial retreat. The largest contributions to global melting came from Alaska and the Canadian Arctic, accounting for 22% and 20% respectively. Following them were the edge glaciers of Greenland at 13% and the Southern Andes at 10%.
According to the researchers' calculations, since 2000, the global ice mass has decreased by 5%, with regional losses ranging from two to 39%. The largest losses were recorded in Central Europe (39%), the Caucasus (35%), and New Zealand (29%).
The GlaMBIE calculations do not contradict previously obtained global data, although there are discrepancies in regional assessments. The new data are more precise and can serve as a basis for comparing different observations and calibrating models. They will be useful in preparing the seventh assessment report of the Intergovernmental Panel on Climate Change (IPCC) under the UN.
At the end of January this year, it became known that the world's largest iceberg is approaching the British island.