page_title: Ice–albedo feedback
section_title: Evidence
hierarchical_section_title: Ice–albedo feedback / Evidence
caption_attribution_description: English: The map shows the difference between the amount of sunlight Greenland reflected in the summer of 2011 versus the average percent it reflected between 2000 to 2006. Virtually the entire ice sheet shows some change, with some areas reflecting close to 20 percent less light than a decade ago. The map is based on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA’s Terra and Aqua satellites. It was produced as part of the National Oceanic and Atmospheric Administration’s Arctic Report Card.
context_page_description: Ice–albedo feedback is a positive feedback climate process where a change in the area of ice caps, glaciers, and sea ice alters the albedo and surface temperature of a planet. Ice is very reflective, therefore some of the solar energy is reflected back to space. Ice–albedo feedback plays an important role in global climate change. However, if warm temperatures decrease the ice cover and the area is replaced by water or land the albedo would decrease. This increases the amount of solar energy absorbed, leading to more warming. The effect has mostly been discussed in terms of the recent trend of declining Arctic sea ice. The change in albedo acts to reinforce the initial alteration in ice area leading to more warming. Warming tends to decrease ice cover and hence decrease the albedo, increasing the amount of solar energy absorbed and leading to more warming. In the geologically recent past, the ice-albedo positive feedback has played a major role in the advances and retreats of the Pleistocene ice sheets. Inversely, cooler temperatures increase ice, which increases albedo, leading to more cooling.
context_section_description: Snow and ice-albedo feedback tend to amplify regional warming due to anthropogenic climate change. Due to this amplification the cryosphere is sometimes called the "natural thermometer" of Earth because changes in each of its components have long lasting effects on the systems (biological, physical and social) of Earth. Internal feedback processes may also potentially occur. As land ice melts and causes eustatic sea level rise, it can also potentially induce earthquakes as a result of post-glacial rebound, which further disrupts glaciers and ice shelves. If sea-ice retreats in the Arctic, the albedo of the sea will be darker which means more warming. Similarly, if the Greenland or Antarctic land ice retreats, the darker underlying land is exposed and more solar radiation is absorbed.
caption: Albedo change in Greenland
exif: {}