Average monthly Arctic sea ice extent data shows a clear deceasing trend since 1979.
The extent of Arctic sea ice extent fell to 4.10 million square kilometers on August 26, 2012.
Based on predictions of sea ice extent from climate change models, the penguins are likely to see their numbers plummet by 95% by 2100.
The aim of the study was to compare two groups of animals that lived during periods when sea ice extent and pollution levels were very different.
Credit: National Snow and Ice Data CenterThe graph above shows daily Arctic sea ice extent as of March 22, 2011, along with daily ice extents for 2006, which had the previous lowest maximum extent, and 2007, the year with the lowest minimum extent in September.
In the Lords (from 2.30pm) questions from peers range across the record-low sea ice extent in the Arctic Ocean during the past year and the likely future of oil prices , before peers continue the marathon committee stage consideration of the Growth and Infrastructure Bill.
Satellites have long been used to track ice extent (area), but calculating the thickness of the marine floes requires the overflying spacecraft to gauge the difference between the top of the ice surface and the top of the water - a relatively simple calculation then gives the overall volume.
The analysis produced a summer Arctic sea-ice minimum extent of 6.9 million sq km.
BBC: Earliest satellite maps of Antarctic and Arctic sea-ice
Since 1979, when NASA first began recording satellite ice images, scientists have seen a 13% decline per decade in the minimum summertime extent of sea ice, and in late August, NASA confirmed that the ice was at an all time low.
Each year, the Arctic sea ice reaches its minimum extent in September.
Weather is caused by disturbances within the atmosphere, but climate is controlled by external influences, such as the distribution of oceans and continents, the extent of ice and snow-cover, variations in the amount of energy from the sun, and changes in the chemical composition of the atmosphere.
In the past, researchers have used data from planes that fly criss-crossing paths over Greenland to assess the extent of its ice sheets.
What is more, the extent of sea ice cover influences the abundance of krill and the fish species that eat them - both food sources for the penguins.
The extent of sea ice in the Antarctic has been relatively stable in recent years (unlike in the Arctic), although this picture hides some fairly large regional variations.
For the Arctic ice melt to make sense, all you have to do is watch this YouTube video, from the National Oceanic and Atmospheric Administration, which shows the puny extent of sea ice in 2012 compared with the historical average.
Thanks to data collected and disseminated by the Arctic Regional Ocean Observing System (Arctic ROOS) and by national observing efforts, information about the extent of the Arctic sea ice is reported every few days, providing an early warning of changing conditions in the Arctic Ocean.
The Franz Josef glacier on the west side of the Southern Alps of New Zealand advanced sharply during the period of the Little Ice Age, actually invading a rain forest at its maximum extent in the early 1700s.
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