What is ice-albedo feedback

Ice–albedo feedback is a positive (exacerbating) feedback climate process where a change in the area of ice caps, glaciers, and sea ice alters the albedo and surface temperature of Earth. It is prominent in areas where a patch of sea ice completely melts, and results in uncovering darker seawater surface that absorbs more sunlight than ice. Ice reflects some of the solar energy back to space because it is highly reflective. If an equivalent area of ice is replaced by water or land, (having a lower albedo value) reflects less and absorbs more energy, resulting in a warmer Earth.

 Recently, it was reported that the Arctic Ocean may become functionally ice-free for part of each year between 2044 and 2067. Further, the Arctic region is heating up twice as fast as the rest of the globe. One reason for this was attributed to ice-albedo feedback mechanism.

Ice albedo feedback’s relationship with climate change:

Due to increase in temperature, the process results in more melting of ice from underneath, while greenhouse gases in the atmosphere warm the surface resulting in increased humidity. This leads to further melting of ice, which exposes more water to sunlight. Thus, climate change reinforces ice albedo feedback and vice-versa.

Ice-albedo feedback tends to amplify regional warming due to anthropogenic climate change. Due to this amplification, the cryosphere is sometimes called the “natural thermometer” of the earth because changes in each of its components have long lasting effects on biological, physical and social systems on Earth.

There is also potential for increased methane and carbon dioxide release as a result of warming of terrestrial permafrost. Also, with sea ice melting earlier, algae and phytoplankton populations peak earlier and start to decline sooner. For instance, in the Arctic region, crustaceans and fish like the Arctic cod struggle to find enough food and as a consequence impact food chains.

It must be noted that sea ice loss is not just a warning sign of climate change –it is a phenomena that actively drives ecological change. Thus, global efforts must be taken to prevent further melting of sea ice by constantly monitoring sea ice loss and taking adequate measures to prevent human- induced climate change.