“Melting Away: Tropical Glaciers in the Andes Are Shrinking Faster Than Ever Before”
Researchers at the University of Wisconsin-Madison, in collaboration with colleagues from Boston College and Tulane University, have made a groundbreaking discovery regarding the state of high-altitude tropical glaciers in the Andes Mountains. Their findings, published in the journal Science on August 2, 2024, reveal that these glaciers are likely smaller now than they have been at any point since the end of the last ice age 11,700 years ago.
The study, led by former Boston College graduate student Andrew Gorin (now at the University of California, Berkeley) and guided by UW-Madison professor Shaun Marcott, sheds light on the alarming rate at which these glaciers are shrinking due to the effects of global climate change. The researchers believe that the tropical Andes may be the first region in the world to surpass this threshold, making them a potential indicator of what lies ahead for glaciers worldwide.
Glaciers form over time in areas where winter snowfall accumulates and compacts into ice that moves under its own weight. However, rising temperatures caused by climate change are causing these glaciers to melt at a faster rate than they can replenish, leading to their gradual disappearance.
To determine the extent of glacier retreat in the Andes, the team analyzed the geochemistry of bedrock near the edges of four glaciers using satellite imagery and on-the-ground observations. By measuring the concentrations of beryllium-10 and carbon-14 isotopes in quartz crystals within the bedrock, they were able to ascertain that the exposed rock had only recently been uncovered by melting ice.
The researchers found consistently low concentrations of these isotopes across all sample sites, indicating that the glaciers in the tropical Andes are experiencing unprecedented levels of retreat compared to the recent geological past. This evidence strongly suggests that the region’s glaciers are the first to shrink beyond historical fluctuations, making them a critical indicator of the impact of climate change on ice coverage.
According to Marcott, glaciers are highly sensitive to changes in their climate, making them a key barometer for assessing the effects of global warming. The team’s findings underscore the urgent need for action to mitigate the impacts of climate change and preserve these vital natural resources.
This research was made possible with support from the National Science Foundation, highlighting the importance of continued scientific investigation into the changing state of glaciers worldwide.