The Andean glaciers, predominately located along the border between Chile and Argentina, are in rapid decline. These ice reserves which are critical to the water supplies of 90 million people across South America, are thinning by 0.7 metres a year—35% faster than the global average.
In late March, at the first-ever World Day for Glaciers hosted by UNESCO in Paris, researchers from the University of Sheffield presented a policy brief, ‘The Future of the Andean Water Towers’ outlining how the shrinking of the glaciers poses a very real threat to the water and food security of the millions of people dependent on them.
Mountain ranges force air upwards in a process known as orographic lifting, causing it to cool and form condensation and precipitation. This precipitation—whether it falls as snow, ice, or rain—accumulates in natural reservoirs like glaciers, permafrost, lakes, and wetlands. Over time, it melts and flows as rivers during the dry season, which is especially important in drought years.
This provides drinking water, powers hydroelectric plants, supports industry, and irrigates crops and is used for livestock.
Warmer temperatures caused by climate change mean more precipitation falls as rain instead of snow, the snowfall season becomes shorter, and snowfall tends to happen in fewer but more intense events. This results in less stored water being available for the dry season.
“The first Intergovernmental Panel on Climate Change (IPCC) report on climate change was published in 1990, and since then, very little has been done to curb the global carbon emissions fuelling climate change,” says Dr Jeremy Ely, from the University of Sheffield’s School of Geography and Planning.
“Our brief shows that what scientists have been predicting for years is now coming true, and swift action needs to be taken if we stand any hope of saving and preserving the glaciers that so many people rely on as a source of water.”
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The brief, which draws on years of research and satellite observations, outlines how the shrinking of the glaciers has accelerated in recent decades, with unprecedented rates of ice loss since 2000, coinciding with increased greenhouse gas emissions worldwide.
“Such a loss of ice across the Andes needs urgent attention as it will increase the stress on freshwater resources relied upon by communities and major cities downstream of the glaciers,” says Ely.
The target of the 2015 Paris Agreement – to keep global temperature rises below 1.5°C – was surpassed for several months in 2024, and recent projections of a higher than 2°C warming scenario show that areas of the Andes will be entirely, or almost entirely, ice-free by 2100.
“With temperatures predicted to rise anywhere up to 4.5°C by the end of the century across the Andes, the risks and hazards of climate change will threaten the water and food security of millions of people,” Ely explains.
As glaciers shrink, supply diminishes and many countries will be forced to mitigate the problem by building major water storage infrastructure, such as dams. However, this will take significant investment that poorer countries and those most vulnerable to the effects of climate change may not be able to access.
“All the targets that have been set have already been missed and failed, yet the only way to preserve glaciers is to drastically reduce carbon emissions once and for all,” says Ely. “The situation is serious, and it will take global cooperation to tackle climate change and make a meaningful difference for the communities around the world most vulnerable from the effects of climate change.”
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