Perito Moreno Glacier Retreat – A Stable Giant Now in Decline

1. The Perito Moreno Glacier in Argentina, once known for its unusual long-term stability, is now showing signs of rapid retreat.
2. In April 2025, it witnessed a massive ice calving event, where a block of ice the size of a 20-story building fell into the water below.
3. The glacier, earlier considered climate-resilient, has started losing mass rapidly since around 2020, raising global concern.

About Perito Moreno Glacier

1. Location: Near El Calafate, in Santa Cruz Province, Argentina.
2. Part of Los Glaciares National Park, a UNESCO World Heritage Site.
3. Commonly called the "White Giant".
4. Size:
   1. Surface Area: 250 sq. km (similar to Patna, Bihar).
   2. Length: 30 km long.
   3. Height: 60 m above water surface.
5. Formed during the last Ice Age, around 18,000 years ago.
6. Major source of freshwater for Argentina.
7. Known for ice calving events, which attract thousands of tourists annually.

About Calving Events: Then and Now

1. Ice calving (large chunks breaking off into water) is a natural process due to the glacier’s forward movement.
2. These events have occurred since at least 1917.
3. Recently, the size and frequency of these events have increased, indicating accelerated retreat.
4. Tour guides and scientists note that icebergs of current size have not been common over the last 20 years.

Signs of Retreat

1. According to a 2024 government-backed report, Perito Moreno has lost 0.85 metres of thickness per year on average since 2015—the fastest retreat in 47 years.
2. The Argentine Institute of Glaciology and Environmental Sciences (IANIGLA) reported in 2023 that since 2020, the glacier had lost over 700 m of mass.
3. This is equivalent to about 7 massive ice blocks breaking off.

Causes of Retreat

1. Climate Change is the main driver.
2. Rising Temperatures: The local region has seen a rise of 0.06°C per decade in air temperature.
3. Decreased Snowfall: Less precipitation has resulted in reduced accumulation of ice.
4. These factors have weakened the glacier’s natural balance, causing it to melt faster than it can rebuild.

Global Perspective on Glacier Melt

1. Perito Moreno’s decline is part of a global trend of glacier retreat.
2. According to a Nature journal (2024) study:
   1. Glaciers are losing 273 billion tonnes of ice per year.
   2. This amount is equal to the world’s 30-year water consumption.
   3. Glacier melt alone has caused nearly 2 cm rise in sea level since 2000.
3. A UNESCO report (March 2025) stated:
   1. Since 1975, glaciers outside Greenland and Antarctica have lost over 9,000 billion tonnes of ice.
   2. This loss is equal to the size of Germany covered with 25 metres of ice.
       

Why This Matters

1. Freshwater Security: Glaciers like Perito Moreno are key freshwater sources. Their retreat affects drinking water, agriculture, and hydropower.
2. Sea-Level Rise: Even small sea level rises (e.g., 2 cm) can increase coastal flooding, displacement, and economic loss.
3. Loss of Biodiversity: Glacier-fed ecosystems are disrupted, threatening species that depend on cold water flow.
4. Disaster Risk: Retreating glaciers increase the threat of Glacial Lake Outburst Floods (GLOFs) and landslides.
5. Tourism Impact: Iconic glaciers are major tourist attractions. Their decline affects local economies.

Way Forward

1. Strengthen international cooperation for glacier research and monitoring.
2. Promote low-emission development pathways globally.
3. Enhance local adaptation strategies in glacier-fed regions (e.g., water conservation, early warning systems for GLOFs).
4. Invest in data sharing platforms, such as glacier observatories and real-time satellite monitoring.