Glaciers ending in lakes, Pg II

Key Highlights:

• A new study reveals that glaciers ending in lakes, oceans, or ice shelves, though only 3.2% of the world's glaciers, accounted for over half of all glacier ice loss between 2000 and 2019.
• These glaciers lost an average of 134 billion tonnes of ice annually during this period.
• The study, led by scientists from the University of Birmingham and the University of Leeds, found that lake-ending glaciers are generally larger and lose ice 57% faster relative to their size compared to land-ending glaciers.
• Lake- and ocean-ending glaciers flow 10% and 44% faster, respectively, than land-ending glaciers.
• The rapid ice loss is attributed to processes like calving (iceberg detachment) and melting by lake water below the waterline.

Detailed Insights:

• The research examined 216,502 glaciers globally, excluding the Greenland and Antarctic ice sheets, to classify their termination types.
• Current models for projecting glacier change do not fully account for the dynamics of lake-ending glaciers, indicating a need for refinement.
• Glacier melt contributes significantly to global sea-level rise, with glaciers being the second-largest contributor after ocean thermal expansion.
• Between 2000 and 2023, glaciers lost 6,542 billion tonnes of ice, contributing 18 mm to global sea-level rise.
• The rate of glacier ice loss has accelerated, with a 36% increase in the second half of the 2000-2023 period compared to the first half.
• Melting glaciers also impact regional freshwater resources, affecting water supply for consumption, irrigation, and hydroelectric power generation.
• The United Nations has designated 2025 as the International Year of Glaciers' Preservation to raise global awareness about their critical role.
• Meeting the Paris Agreement goal of limiting global temperature rise to 1.5°C could preserve twice as much glacier mass compared to current warming trajectories.

Scientific/Technical Concepts Involved:

• Calving: The process where chunks of ice break off from the edge of a glacier, typically into a body of water, forming icebergs.
• Glacier Mass Balance: The difference between the amount of snow and ice a glacier gains and the amount it loses through melting, sublimation, and calving.
• Glacial Lake Outburst Flood (GLOF): A sudden release of water from a glacial lake due to the failure of its natural dam, often causing catastrophic downstream flooding.