Large variations in Arctic sea ice
Polar ice much less stable than previously thought
For the last 10,000 years, summer sea ice in the Arctic Ocean has been far from constant. For several thousand years, there was much less sea ice in The Arctic Ocean – probably less than half of current amounts. This is indicated by new findings by the Danish National Research Foundation for Geogenetics at the University of Copenhagen. The results of the study will be published in the journal Science.
Sea ice comes and goes without leaving a record. For this reason, our knowledge about its variations and extent was limited before we had satellite surveillance or observations from airplanes and ships. But now researchers at the Danish National Research Foundation for Geogenetics at the Natural History Museum of Denmark (University of Copenhagen) have developed a method by which it is possible to measure the variations in the ice several millennia back in time.
The results are based on material gathered along the coast of northern Greenland, which scientists expect will be the final place summer ice will survive, if global temperatures continue to rise.
This means that the results from northern Greenland also indicate what the conditions are like in the ocean. (EurekAlert)
The Danish National Research Foundation for Geogenetics at the University of Copenhagen has announced that for several thousand years, there was much less sea ice in The Arctic Ocean – probably less than half of current amounts.
The research team says the findings indicate that even with a reduction to less than 50% of the current amount of sea ice the ice will not reach a point of no return: a level where the ice no longer can regenerate itself even if the climate was to return to cooler temperatures.
The researchers who published their study in the journal Science, developed a method measuring the variations in the ice several millennia back in time. (Irish Weather Online)
Arctic ‘tipping point’ may not be reached
(Matt McGrath, BBC World Service)
4 Reasons We Should Be Worried About July’s Near Record-Breaking Sea Ice Melt
August 4, 2011
The National Snow and Ice Data Center (NSIDC) just released figures for July’s arctic sea ice averages. The bad news: Last month’s average arctic sea ice extent is the second-greatest loss of summer sea ice since satellite tracking began in 1979.
Arctic sea ice extent basically measures how far sea ice stretches over the Earth’s surface. It includes any satellite data cell with a surface that is 15% ice (opposed to cells that have less surface ice and more water). In case you want to geek out further on the definition and process of these measurements, the NSIDC fleshes it out here. (It should also be noted that sea ice is not the same as glaciers, icebergs, or other frozen masses that float in the ocean. Sea ice is simply frozen ocean water, and is usually covered with snow.)
Though the impact of the disappearing ice is much more extensive than the short list below, here are a few effects that have manifested as of late: (UN Dispatch)