How quickly are the polar ice caps melting?

Labels

Description

Answers (4)

• 
  Moriarty
  Aug 11, 2011

  Although the melting of polar ice is a natural phenomenon that occurs annually, recent statistics show that the current rate at which this happens has been dramatically increasing. During the summer season a certain amount of sea ice melts, only to reform every winter, NASA Earth Observatory[1] computes natural average decline in polar ice measured per decade at around 3.7% (45,100 km3 /year) but recent trends have shown that the amount of ice melt has increased to a little over 7.5% per decade (57,000 km3 /year).

  Animated images from the national Snow and Ice data Center displays these changes more plainly. It can be clearly seen from satellite images taken from 1979 to 2010 that this decline have been increasing rapidly since record keeping began.

  Arctic sea ice September minimums: http://nsidc.org/sotc/sea_ice_animation.html

  Arctic sea ice March maximums: http://nsidc.org/sotc/sea_ice_animation_max.html

  Antarctic sea ice March minimums: http://nsidc.org/sotc/sea_ice_animation_ant.html

  Antarctic sea ice September maximums: http://nsidc.org/sotc/sea_ice_animation_ant_max.html

  And this comparative mosaic showing minimum points in the Arctic from 1979 to 2007 http://nsidc.org/sotc/sea_ice_mosaic.html

  An article from National Geographic News claims that greenhouse gas emissions from human activities that have increased the global average temperature rate by almost twice, combined with the natural ice decline cycles have caused such dramatic changes. Although it does say that there is a certain degree of uncertainty whether such changes are the results of a natural variability it does claim in the end that there is a consensus between actual observations and predicted models that such dramatic decline is caused by human activity. [2]

  The effects of these drastic changes cannot be ignored as the global impact of rising water levels will not only cause the loss of natural wildlife but threaten human settlements near various coastal areas on Earth.

  There are additional statistics provided by the World Glacier Monitoring Service that may provide you additional information for any other details that you may wish to find complete with various other links to helpful sites and further reading: http://www.geo.uzh.ch/microsite/wgms/index.html

  links :

  1. http://earthobservatory.nasa.gov/Features/SeaIce/page3.php

  2. http://news.nationalgeographic.com/news/2007/03/070330-warming-arctic.html

• 
  vishal730
  Aug 04, 2011

  Hello. Here is what I can find regarding this zomb.

  Global warming and rising sea levels are truly getting to be two of the most challenging and concerning issues our world is facing today. Melting ice caps on land, such as in Antarctica in the South Pole, are the ones considered to cause the rise of sea levels; melting ice caps already on the water such as in the North Pole do not contribute to this issue. Nevertheless, melting Arctic ice caps are still disturbing as our world will have less protection from the sun. According to NASA, ice caps provide better protection as they bounce back sunlight to the atmosphere compared to ocean water that absorbs light. This plays a major factor to global warming.

  NASA research studies show the polar ice caps in the Arctic melting at a rate of about 9 to 10 percent per decade. While measurement of the rate at which ice sheets melt on large masses of land (particularly Antarctica and Greenland) prove to be more challenging, data compiled by the GRACE or Gravity Recovery and Climate Experiment estimate ice sheet melting at a rate of more than 100 billion metric tons per year on West Antarctica and a rate of more than 200 billion metric tons on Greenland. At this rate, the sea level is expected to rise at about 0.2 inch each year.

  Aside from NASA and GRACE (which is a joint venture of NASA with German Space Agency), it is somewhat comforting to know there are several research teams that study the phenomenon and effect of melting ice caps around the world. To name a few, these teams include British Antarctic Survey (BAS), the global network of researchers called POLENET (The Polar Earth Observing Network), Nature Geoscience scientists, the United States’ Natural Resources Defense Council (NRDC), and the ICECAP (Investigating the Cryospheric Evolution of the Central Antarctic Plate) team formed by Australia, US and UK.

  Sources: NASA, NRDC, Time, BBC

• 
  gethin
  Aug 06, 2011

  Dire warnings about sea level rising have been prevalent for some time. Take for example this article from 1952, 60 years ago now: http://stevengoddard.wordpress.com/2011/08/03/1952-polar-ice-caps-melting-exceedingly-fast-glaciers-have-shrunk-50/. Sensationalist? Perhaps. What would actually happen if the polar icecaps melted? The sea level wouldn’t rise seeing as “iceberg displaces a volume of water that has a weight equal to that of the iceberg” - http://science.howstuffworks.com/environmental/earth/geophysics/question473.htm. However, melting glaciers is another story.

  How much will the sea level rise in the next 100 years? It’s hard to say. Will more water return to ground water reserves rather than causing sea levels to rise? Estimates for sea level rise vary wildly depending on the resource:

  12cm- NASA/Harvard: http://adsabs.harvard.edu/abs/2011NatGe...4...71P 38.7cm - Nature: http://www.uio.no/studier/emner/matnat/geofag/GEO4420/h07/papers/Raper%20and%20Braithwaite-nature04448.pdf 18-58cm - Nature: http://www.nature.com/climate/2010/1004/full/climate.2010.29.html ~60cm - IPCC: http://www.sciencemag.org/content/328/5985/1517.short

  This article from 1990 states that sea levels rise approximately 1-2mm per year on average: http://igitur-archive.library.uu.nl/phys/2007-0720-200452/oerlemans_90-sealevelrise.pdf

  Danish research shows that there is evidence that there was less ice and a warmer climate 5000 years ago during the Holocene Climate Optimum without adverse affects. http://pajamasmedia.com/tatler/2011/08/04/yet-another-global-warming-keystone-crumbles-arctic-ice-tipping-point-disproven/

• 
  shantaine.vanw
  Aug 07, 2011

  climate change has been a pressing issue as the average global temperature increases due to global warming.According to the telegraph,(http://www.telegraph.co.uk/earth/environment/climatechange/8586961/Sea-levels-rising-at-fastest-rate-in-2000-years.html)sea levels are rising at its fastest rate in comparison to the 2100 years.
  

  this statistics had been measure by a group of reserchers who examined examined the remains of foraminifera tiny plankton-like creatures.the difference in location of these creatures gave an indication of the depth of the sea level at that point in time. estimates have been made that sea level would rise by 75- 190cm between 1990 and 2100.

  this link gives the global mean seal level statistic: http://sealevel.colorado.edu/

  interestingly enough,NASA does have 'eyes in the skies' and they do monitor the melting polar ice caps. (http://www.jpl.nasa.gov/news/news.cfm?release=2009-107).by using NASA's Ice, Cloud and land Elevation Satellite(ICESat) to make the first basin-wide estimate of the thickness and volume of the Arctic Ocean's ice cover,we can roughly deduce the rate at which the polar ice caps are melting.Using ICESat measurements, scientists found that overall Arctic sea ice thinned about 0.17 meters (7 inches) a year, for a total of 0.68 meters (2.2 feet) over four winters.
  if you're interested in images,this link could be quite helpful.

  also, strongly urge that you watch the documentary 'an inconvenient truth"...its pretty insightful