In a sobering assessment of the impacts of climate change, a new study spanning over two decades has revealed that melting glaciers have caused global sea levels to rise by nearly two centimeters since the turn of the century. The research, led by scientists from the Universities of Edinburgh and Zurich, found that the world’s glaciers collectively lost a staggering 6.5 trillion tonnes of ice between 2000 and 2023, equivalent to 30 years’ worth of water consumption for the entire global population.
The findings, published in the journal Nature, are part of the Glacier Mass Balance Intercomparison Exercise (Glambie), which combines and analyzes data from field measurements and various satellite missions. The study shows that glaciers lost an average of 273 billion tonnes of ice every year during the 23-year period, with the rate of loss accelerating significantly over time. Alarmingly, 36% more ice melted between 2012 and 2023 compared to the previous decade.
Regional Variability in Glacier Loss
The study also highlighted stark regional differences in glacier loss. While the Antarctic and subantarctic islands lost 2% of their total volume, central Europe’s glaciers experienced a staggering 39% decline. Professor Noel Gourmelen, co-lead author of the study, emphasized the rapid changes occurring in some regions:
“These numbers are staggering. They serve as a reminder that things are changing fast in some regions.”
Prof Noel Gourmelen, University of Edinburgh
Accelerating Pace of Glacier Melt
The accelerating rate of glacier loss is particularly concerning, as it confirms that the pace of melting is speeding up over time. Professor Andrew Shepherd from Northumbria University warned of the consequences:
“Even small amounts of sea level rise matter because it leads to more frequent coastal flooding. Every centimetre of sea level rise exposes another 2 million people to annual flooding somewhere on our planet.”
Prof Andrew Shepherd, Northumbria University
Impacts on Freshwater Resources and Hydropower
Beyond the direct effects on sea level rise, the loss of glaciers also threatens regional freshwater supplies and hydropower generation. Around 2 billion people worldwide depend on meltwater from glaciers, making their retreat a significant problem for remote communities and those already facing water scarcity. In countries like Iceland and Switzerland, as well as parts of the Andes, glacial meltwater is crucial for electricity production through hydropower.
“Around 2 billion people depend on meltwater from glaciers and so their retreat is a big problem for society. It’s not just that we are losing them from our landscape, they are an important part of our daily lives.”
Prof Andrew Shepherd, Northumbria University
Glaciers as a Biometer for Climate Change
The study’s findings underscore the role of glaciers as a key indicator of the impacts of climate change over the past two decades. As efforts to mitigate global warming continue, monitoring glacier activity will be crucial in measuring the effectiveness of these actions.
“Glaciers have a real impact. They are a biometer for climate change, so the findings are a measure of the impact climate change has had over the past 20 years. As we take action to try to mitigate this, following glacier activity will be a way of measuring our effectiveness in dealing with a changing climate.”
Prof Noel Gourmelen, University of Edinburgh
Urgent Action Required
The study’s alarming findings underscore the urgent need for accelerated action to combat climate change and its far-reaching consequences. As Professor Martin Siegert from the University of Exeter pointed out, the two-centimeter sea level rise attributed to melting glaciers is just a fraction of the potential impact from the planet’s ice sheets, particularly those in Greenland and Antarctica.
The international community must rally together to drastically reduce greenhouse gas emissions, invest in climate adaptation measures, and support vulnerable communities facing the brunt of the impacts. Only through swift, coordinated, and ambitious action can we hope to limit the devastating effects of climate change, including the accelerating loss of the world’s glaciers and the cascading consequences for sea levels, water resources, and the millions of people who depend on them.
