Researchers from the University of Wisconsin-Madison have discovered evidence that glaciers high in the Andes Mountains are likely at their smallest size since the end of the last ice age 11,700 years ago. This makes the tropical Andes the first region in the world to reach this threshold due to the warming global climate. The shrinking glaciers are considered possible indicators of what may happen to glaciers worldwide in the future. The study, led by Professor Shaun Marcott and his colleagues at Boston College and Tulane University, was published in the journal Science on August 2, 2024.
Glaciers in the Andes grow slowly over time in areas where there is not enough warm weather in the summer to melt all the snowfall from the previous winter. Satellite images and on-the-ground observations have shown that high-altitude glaciers in the Andes have been shrinking as temperatures rise, causing them to melt faster than they can be replenished with snow. However, it was unclear whether the current size of the glaciers is significantly smaller compared to previous periods. The team wanted to determine whether the melting of the glaciers due to human-induced climate change is different from the natural fluctuations they have experienced in the past.
To answer this question, researchers analyzed the geochemistry of bedrock samples from areas near the edges of four glaciers in the high tropical Andes that were recently exposed due to melting ice. They looked for specific isotopes of beryllium-10 and carbon-14 in the quartz crystals of the bedrock, which are only present in rock that has been exposed to the surface over time. The concentrations of these isotopes were found to be “remarkably low” in the samples, indicating that the bedrock had only recently been exposed near the glaciers. Additional analyses confirmed that the low concentrations were consistent across all sample locations, suggesting that the melting ice, rather than erosion, had exposed the bedrock.
The researchers believe that the shrinking glaciers in the tropical Andes are the first to experience such significant reduction beyond what has been seen in recent geological history. Glaciers are highly sensitive to changes in the climate, making them a key indicator of the impact of a warming climate. The findings from this study may provide insights into what could happen to glaciers in other regions, such as the Western United States, in a future without ice. The study was funded by the National Science Foundation and highlights the urgent need to address climate change and its effects on glaciers worldwide.
The results of this research could have significant implications for the future of glaciers globally and the impact of climate change on ice-covered regions. The findings suggest that the shrinking glaciers in the tropical Andes are a direct result of human-induced climate change, making them a critical indicator of the potential impacts on glaciers worldwide. The study provides valuable insights into the sensitivity of glaciers to changes in the climate system and highlights the importance of addressing climate change to protect these vital ecosystems. The research underscores the urgent need for action to reduce greenhouse gas emissions and mitigate the effects of climate change on glaciers and ice-covered regions.
The study conducted by researchers at the University of Wisconsin-Madison sheds light on the current state of glaciers in the Andes Mountains and their vulnerability to climate change. The findings indicate that the glaciers in the tropical Andes are at their smallest size since the end of the last ice age, raising concerns about the future of glaciers globally. The research underscores the need for immediate action to address climate change and protect glaciers and ice-covered regions from further deterioration. By studying the impact of warming temperatures on glaciers, scientists can better understand the implications for these vital ecosystems and work towards solutions to mitigate the effects of climate change on glaciers worldwide.