Impacts on ice and snow

Glaciers around the world, from the Himalayas to the Andes, and from the Rockies to the Alps, are retreating at unprecedented rates. This not only contributes to sea-level rise but also affects freshwater availability for millions of people downstream.

The extent and thickness of Arctic sea ice have decreased dramatically, particularly in the summer. This loss of sea ice has several consequences, including altering local ecosystems, affecting indigenous peoples’ ways of life, potentially changing ocean circulation patterns, and impacting global weather patterns.

The Greenland and Antarctic ice sheets are losing mass at an accelerating rate. Ice loss from these areas is a significant contributor to global sea-level rise. The potential collapse of parts of the Antarctic ice sheet could lead to several meters of sea-level rise over the coming centuries.

The duration of snow cover over land in the Northern Hemisphere is decreasing, with snow melting earlier in the spring. This affects water resources, as many regions rely on meltwater from seasonal snowpacks for their freshwater supply.

Vast areas of the Arctic and sub-Arctic are underlain by permafrost, which is soil that has remained frozen for two or more consecutive years. Thawing permafrost can release methane and carbon dioxide, potent greenhouse gases that contribute to further warming. It also damages infrastructure built on top of it and can lead to landscape changes like thermokarst lakes.

Ice and snow have high albedo, meaning they reflect a significant portion of the sun’s energy back into space. As ice and snow cover decrease, less solar radiation is reflected, and more is absorbed by the Earth’s surface, leading to further warming.

As glaciers retreat, they can leave behind lakes dammed by ice or moraines (accumulations of glacial debris). These lakes can burst and cause catastrophic flooding downstream.

Mountain glaciers are critical water sources for ecosystems and human use. Their retreat affects river flows, impacting water availability for ecosystems, agriculture, hydropower, and domestic use.

Species that depend on sea ice, such as polar bears, seals, and certain penguin species, are facing habitat loss. Terrestrial species that rely on snow cover, like the snowshoe hare, are also affected by changing snow patterns.

The ski and winter sports industry is facing challenges due to less reliable snowfall, affecting economies that depend on winter tourism.