In News:

• The Perito Moreno Glacier, often referred to as the ‘White Giant’, is Argentina’s most iconic glacier, located in the Los Glaciares National Park, a UNESCO World Heritage Site.
• Situated in the Andes Mountains, near El Calafate in Santa Cruz province, this glacier spans approximately 250 sq km—about the size of Patna, Bihar—and stretches 30 km in length, with ice walls rising 60 meters above water.
• Formed during the last Ice Age (~18,000 years ago), Perito Moreno has historically remained unusually stable, defying the global trend of rapid glacier retreat. However, this stability changed around 2020, raising alarms among scientists.

Recent Developments and Ice Calving Events

• Perito Moreno is globally renowned for its ice calving events, where massive blocks of ice break off into the lake with thunderous crashes. These events, though natural due to the glacier’s forward motion, have recently become more intense.
• On April 21, 2025, a colossal ice chunk the size of a 20-story building plunged 70 meters into the water—an increasingly frequent occurrence in the past 4–6 years.
• According to local experts and a 2024 government-backed report, the glacier has been retreating steadily since 2015, with an average mass loss of 0.85 meters annually—the fastest in nearly five decades.
• Between 2020 and 2023, the glacier lost over 700 meters of mass, equivalent to around seven large ice blocks.

Causes: Global Warming & Climate Impact

• The primary cause behind this dramatic retreat is climate change. Scientists from IANIGLA (Argentine Institute of Glaciology and Environmental Sciences) and CONICET state that the region has experienced an air temperature rise of 0.06°C per decade and reduced precipitation, leading to less snow accumulation and thinning of the glacier.

Global Perspective on Glacier Retreat

Perito Moreno is now part of a larger, alarming global trend.

• A 2024 study in Nature estimates that glaciers worldwide are losing 273 billion tonnes of ice annually, contributing to a 2 cm rise in global sea levels this century alone.
• A UNESCO report (March 2025) highlighted that glaciers (excluding Greenland and Antarctica) have shed over 9,000 billion tonnes of ice since 1975—comparable to an ice block the size of Germany with 25 meters thickness.

Environmental Significance

• Freshwater Source: Perito Moreno is a major reservoir of freshwater in Argentina.
• Tourism: The glacier attracts global tourists, boosting the local economy.
• Climate Indicator: Its recent retreat reflects the delayed but accelerating impact of global warming, making it a critical environmental bellwether.