Glaciers Worldwide are Melting Faster Causing Sea Levels to Rise More

Anthropogenic climate change is creating a vicious circle where rising temperatures are causing glaciers to melt at an increasing rate. In addition to contributing to rising sea levels, coastal flooding, and extreme weather, the loss of polar ice and glaciers is causing Earth’s oceans to absorb more solar radiation. The loss of glaciers is also depleting regional freshwater resources, leading to elevated levels of drought and the risk of famine. According to new findings by an international research effort, there has been an alarming increase in the rate of glacier loss over the last ten years.

The research was conducted by the Glacier Mass Balance Intercomparison Exercise (GlaMBIE) team, a major research initiative coordinated by the World Glacier Monitoring Service (WGMS). Located at the University of Zurich in collaboration with the University of Edinburgh and Earthwave Ltd, this international data repository and data analyzing service generates community estimates of glacier mass loss globally. The paper that details their research and findings, “Community estimate of global glacier mass changes from 2000 to 2023,” was published on February 19th in the journal Nature.

As part of their efforts, the team coordinated the compilation, standardization, and analysis of field measurements and data from optical, radar, laser, and gravimetry satellite missions. These include satellite observations from NASA’s Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2), the NASA-DLR Gravity Recovery and Climate Experiment (Grace), the GLR’s TanDEM-X mission, and the ESA’s CryoSat missions, and more.

Combining data from multiple sources, the Glambie team produced an annual time series of global glacier loss from 2000 to 2023. In 2000, glaciers covered about 705,221 square km (272,287 mi2) and held an estimated 121,728 billion metric tons (134,182 US tons) of ice. Over the next twenty years, they lost 273 billion tonnes of ice annually, approximately 5% of their total volume, with regional losses ranging from 2% in the Antarctic and Subantarctic to 39% in Central Europe. To put that in perspective, this amounts to what the entire global population consumes in 30 years.

In short, the amount of ice lost rose to 36% during the second half of the study (2012 and 2023) compared to the first half (2000-2011). Glacier mass loss over the whole study period was 18% higher than the meltwater from the Greenland Ice Sheet and more than double that from the Antarctic Ice Sheet. Michael Zemp, a noted glaciologist who co-led the study, said in an ESA press release:

“We compiled 233 estimates of regional glacier mass change from about 450 data contributors organized in 35 research teams. Benefiting from the different observation methods, Glambie not only provides new insights into regional trends and year-to-year variability, but we could also identify differences among observation methods. This means that we can provide a new observational baseline for future studies on the impact of glacier melt on regional water availability and global sea-level rise.”

Globally, glaciers collectively lost 6,542 tonnes (7,210 tons) of ice, leading to a global sea-level rise of 18 mm (0.7 inches). However, the rate of glacier ice loss increased significantly from 231 billion tonnes per year in the first half of the study period to 314 billion tonnes per year in the second half – an increase of 36%. This rise in water loss has made glaciers the second-largest contributor to global sea-level rise, surpassing the contributions of the Greenland Ice Sheet, Antarctic Ice Sheet, and changes in land water storage. Said UZH glaciologist Inés Dussaillant, who was involved in the Glambie analyses:

“Glaciers are vital freshwater resources, especially for local communities in Central Asia and the Central Andes, where glaciers dominate runoff during warm and dry seasons. But when it comes to sea-level rise, the Arctic and Antarctic regions, with their much larger glacier areas, are the key players. However, almost Thione-quarter of the glacier contribution to sea-level rise originates from Alaska.”

These results will provide environmental scientists with a refined baseline for interpreting observational differences arising from different methods and for calibrating models. They hope this will help future studies of global ice loss by narrowing the projection uncertainties for the twenty-first century. These research findings are the culmination of many years of cooperative studies and observations, which included the use of satellites that were not specifically designed to monitor glaciers globally. As co-author Noel Gourmelen, a lecturer in Earth Observation of the Cryosphere at the University of Edinburgh, said:

“The research is the result of sustained efforts by the community and by space agencies over many years, to exploit a variety of satellites that were not initially specifically designed for the task of monitoring glaciers globally. This legacy is already producing impact with satellite missions being designed to allow operational monitoring of future glacier evolution, such as Europe’s Copernicus CRISTAL mission which builds on the legacy of ESA’s CryoSat.”

The study also marks an important milestone since it was released in time for the United Nations’ International Year of Glaciers’ Preservation and the Decade of Action for Cryospheric Sciences (2025–2034). Said Livia Jakob, the Chief Scientific Officer & Co-Founder at Earthwave, hosted a large workshop with all the participants to discuss the findings. “Bringing together so many different research teams from across the globe in a joint effort to increase our understanding and certainty of glacier ice loss has been extremely valuable. This initiative has also fostered a stronger sense of collaboration within the community.”

The study also illustrates the importance of collective action on climate change, which is accelerating at an alarming rate. Research that quantifies glacial loss, rising sea levels, and other impacts is key to preparing for the worst. It’s also essential to the development of proper adaptation, mitigation, and restoration strategies consistent with the recommendations made by the UN Intergovernmental Panel on Climate Change (IPCC).

Further Reading: ESA

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