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A SWAG��Ƶ researcher is part of a team that has, for the first time, shown how rapidly glaciers can lose mass based on various future development and carbon emission scenarios and found that — in the worst-case scenario — two out of three of the world’s glaciers could melt into the sea within the next century.

Will Kochtitzky, Ph.D., visiting assistant teaching professor of geographic information systems (GIS) within the School of Marine and Environmental Programs, is an author on the groundbreaking study, published in Science on Jan. 5.

The international effort, led by David Rounce, Ph.D., assistant professor of civil and environmental engineering at Carnegie Mellon University, shows that the world could lose as much as 41% of its total glacier mass this century — or as little as 26% — depending on today’s climate change mitigation efforts.

The research team concluded that, with continued investment in fossil fuels, over 40% of the glacial mass will be gone within the century and over 80% of glaciers by number could disappear by the year 2100.  

Even in a best-case, low-emissions scenario, where the increase in global mean temperature is limited to +1.5° C relative to pre-industrial levels, over 25% of glacial mass will be gone and nearly 50 % of glaciers by number are projected to disappear. At a rise of 3° C, smaller glacial regions in Central Europe, low latitudes like the Andes, and the upper areas of North America could disappear almost completely.

The team utilized a set of “shared socioeconomic pathways” (SSPs) to model future scenarios for climate change, based on the carbon intensity of future development, including how quickly the world transitions to renewable energy. SSPs have only recently been used to produce global predictions for total glacial mass change, and these new pathways illustrate a more complete picture of socioeconomic trends that could impact future greenhouse gas emissions.

Most of the glaciers lost are small by glacial standards (less than one square kilometer, or about 200 American football fields), but their loss can negatively impact local hydrology, tourism, glacier hazards, and cultural values, illustrating the urgency needed in undertaking efforts to mitigate global warming and sea level rise.

“Our work shows that reducing carbon emissions now can have a big impact on the future of glaciers on our planet,” Kochtitzky remarked. “The sea level has already risen by 7 to 8 inches in Maine since 1900, and this work shows that our decisions today will impact how much sea level rise we see in the coming decades.”