Unprecedented retreat of the tropical Andes glaciers

A new study published in Science reveals that four glaciers in the high Andes of Colombia, Peru, and Bolivia are now smaller than they have been in over 11,700 years, since the start of the Holocene. Led by Jeremy Shakun of Boston College and first author Andrew Gorin of the University of California, Berkeley, the research highlights the profound impact of global warming on tropical glaciers. To obtain these insights, the team measured beryllium-10 and carbon-14 isotopes in recently exposed bedrock.

Andean glaciers, which make up 99% of all tropical glaciers globally, are particularly sensitive to rising temperatures. According to the author Shakun, the findings from the Andes serve as a “canary in the coal mine” for global glacier retreat, showing that the tropics have warmed beyond their Holocene range and into the Anthropocene, an era marked by human-driven global changes. Our Earth systems are intrinsically linked and changes in the poles also contribute to increase in global atmospheric and ocean temperatures and resultant accelerated retreat of tropical glaciers, although located far from the poles (IPCC). Another 2022, study showed that the tropical Andean glaciers reduced from 2429.38 km2 to 1409.11 km2 between 1990 and 2020, representing a loss of 42% of the total glacier area. The new data from the Andes suggest that global glacier retreat is happening faster than previously predicted, potentially decades ahead of earlier estimates.

Retreating glaciers pose several livelihoods risks to the mountain communities and those living downstream, by increasing the risk of floods and impacting water supply. Flooding and water scarcity affect sanitation and further trigger the spread of diseases such as cholera, diarrhea, dysentery, hepatitis A, typhoid and polio exacerbating existing vulnerabilities of these communities (WHO). The retreat of glaciers leads to water scarcity, which in turn impacts food security and power generation. This situation profoundly affects the economic and social lives of the communities dependent on these resources. As some regions of the world have already departed from hospitable climatic conditions, it is more than urgent for world leaders to strengthen policies that support the phase out of fossil fuels at a faster pace than a business-as-usual scenario.

Main image: Queshque glacier in Peru by Emilio Mateo/Aspen Global Change Institute

Image source: GRID Arendal

Image source: GRID Arendal

Image source: GRID Arendal