Konsekwencje globalnego ocieplenia dla kriosfery


  • Jacek A. Jania Wydział Nauk o Ziemi Uniwersytetu Śląskiego, Sosnowiec; Komitet Badań Polarnych PAN

Słowa kluczowe:

cryosphere, climate warming, sea ice, glacier dynamics, sea level rise


Scale of changes of particular components of cryosphere due to global warming is presented. Cryosphere diminishes its spatial extend and the total volume of all kinds of ice is reduced. The Arctic sea ice cover has recently diminished most intensely. It reached its minimal extend (4.28 mln km2) in September 2007. One expects accelerated disintegration of sea ice of the Arctic as a result of coadjuvancy of oceanic and atmospheric factors. In consequence, more intense warming of climate coming from warmer ocean water is predicted in the Arctic basin. Increase of melting of glaciers during the last three decades results in decrease of their extend and thickness. Additionally, more meltwater is reaching bed of glaciers and is accelerating their flow velocity due to faster basal sliding. Such processes result in more intense breaking off the icebergs from fronts of glaciers terminating into the sea. Dynamic response of Greenland outlet tidewater glaciers has been detected after 2000 and it affects significantly global ocean level rise by ca 0.5 mm/yr. The Antarctic Ice Sheet is actually only insignificantly reacting to global warming. The paper discusses possible scenarios of the consequences of dynamic reaction of the West Antarctic Ice Sheet for increasing warming and slow sea level rise. Permafrost is reacting in a less distinct but detectable scale. The paper is giving not only description of consequences of climate warming for cryosphere, important impact of its spatial extend and features on atmosphere and oceans are considered either. A series of positive feedacks between  warming climate and cryosphere are listed. Described evolution of cryosphere is suggesting that distinct trend of climate warming is irreversible for the next centuries. One can also expect systematic rise of global ocean level as the consequence of glacier melting and dynamic transfer of ice masses based on land to the sea.