Ice loss from the world鈥檚 glaciers has accelerated over the past decade, scientists said on Wednesday, warning that melting may be faster than previously expected in the coming years and drive sea levels higher.
The world鈥檚 glaciers, which are important climate regulators and hold freshwater resources for billions, are rapidly melting as the world warms.
In a first-of-its-kind global assessment, an international team of researchers found a sharp increase in melting over the past decade, with around 36 per cent more ice lost in the 2012 to 2023 period than in the years from 2000 to 2011.
On average some 273 billion tonnes of ice are being lost per year 鈥� equivalent to the world population鈥檚 water consumption for 30 years, they said.
The findings are 鈥榮hocking鈥� if not altogether surprising as global temperatures rise with humanity鈥檚 greenhouse gas emissions, said Michael Zemp, a professor at the University of Zurich, who was a co-author of the assessment published in the journal Nature.
Overall, researchers found that the world鈥檚 glaciers have lost around five per cent of their volume since the turn of the century, with wide regional differences ranging from a two-per cent loss in Antarctica to up to 40 per cent in the European Alps.
Zemp said that regions with smaller glaciers are losing them faster, and many 鈥榳ill not survive the present century鈥�.
The research 鈥� coordinated by the World Glacier Monitoring Service, The University of Edinburgh and research group Earthwave 鈥� was an effort to bring together field and satellite measurements to create a 鈥榬eference estimate鈥� for tracking ice loss.
Zemp, who leads the WGMS, said the team鈥檚 observations and recent modelling studies suggest that glacier melt this century will be faster than projected in the most recent assessment by United Nations IPCC climate experts.
鈥楬ence, we are facing higher sea-level rise until the end of this century than expected before,鈥� he said, adding that glacier loss would also impact fresh water supplies, particularly in central Asia and the central Andes.
Glaciers are the second-largest contributor to global sea-level rise 鈥� after the rise caused by the expansion of seawater as it warms.
The nearly two centimetres of sea level rise attributed to glacier melt since 2000 means almost four million more people on the world鈥檚 coasts made vulnerable to flooding, scientists have estimated.
So far smaller glaciers are the main contributors to sea level rise, but Martin Siegert, a Professor at the University of Exeter who was not involved in the study, said the research was 鈥榗oncerning鈥�.
That is because it predicts further glacier losses and could indicate how Antarctica and Greenland鈥檚 vast ice sheets react to global warming.
鈥業ce sheets are now losing mass at increasing rates 鈥� six times more than 30 years ago 鈥� and when they change, we stop talking centimetres and start talking metres,鈥� he said.
Glaciers have been a key bellwether for human-caused climate change for decades, with WGMS data going back more than a century.
In the 20th century, assessments were based on field measurements from some 500 glaciers鈥攊nvolving scientists digging a hole on the top to record the amount of fresh snow that year and then assessing ice amounts lost on the 鈥榯ongue鈥� where the melting ice flows.
More recently, satellites have allowed scientists to better track changes across the world鈥檚 2,75,000 glaciers 鈥� using cameras, radar, lasers and methods to assess the Earth鈥檚 mass.
In January, the United Nations said saving the world鈥檚 glaciers was an important 鈥榮urvival strategy鈥� for the planet.
To do that, 鈥榶ou have to reduce the greenhouse gas emissions, it is as simple and as complicated as that,鈥� said Zemp.
鈥楨very tenth of a degree warming that we avoid saves us money, saves us lives, saves us problems.鈥�