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That’s as well as lakes, and sea. More over this is expected to continue. The Arctic Sea Ice / Ocean is expected to become essentially ice free in summer before mid-century.
Rising temperatures across the U.S. have reduced lake ice, sea ice, glaciers, and seasonal snow cover. All in over the last few decades.
In the Great Lakes, for example, total winter ice coverage has decreased by 63% since the early 1970s. This includes the entire period since satellite data became available. When the record is extended back to 1963 using pre-satellite data. So the overall trend is less negative because the Great Lakes region experienced several extremely cold winters in the 1970s.
So for example, 1963-1972 indicates arctic sea ice changes during the winter of 1962-1963. As well as through the winter of 1971-1972. Only the most recent periods of arctic sea ice loss includes the eleven years from 2003 to 2013. (Data updated from Bai and Wang, 2012).
Sea ice in the Arctic has also decreased dramatically since the late 1970s. That’s particularly in summer and autumn. Since the satellite record began in 1978, minimum Arctic sea ice extent (which occurs in early to mid-September) has decreased by more than 40%.
This decline is unprecedented in the historical record, and the reduction of ice volume and thickness is even greater.
Ice thickness decreased by more than 50% from 1958-1976 to 2003-2008, and the percentage of the March ice cover made up of thicker ice (ice that has survived a summer melt season) decreased from 75% in the mid-1980s to 45% in 2011.
Recent analyses indicate a decrease of 36% in autumn sea ice volume over the past decade.
The 2012 sea ice minimum broke the preceding record (set in 2007) by more than 200,000 square miles. Ice loss increases Arctic warming by replacing white, reflective ice with dark water that absorbs more energy from the sun. More open water can also increase snowfall over northern land areas and increase the north-south meanders of the jet stream, consistent with the occurrence of unusually cold and snowy winters at mid-latitudes in several recent years.
As CNN reported: Over 40% of Greenland experienced melting Thursday, with total ice loss estimated to be more than 2 gigatons (equal to 2 billion tons) on just that day alone.
While Greenland is a big island filled with lots of ice, it is highly unusual for that much ice to be lost in the middle of June. The average “melt season” for Greenland runs from June to August, with the bulk of the melting occurring in July.
To visualize how much ice that is, imagine filling the National Mall in Washington with enough ice to reach a point in the sky eight times higher than the Washington Monument (to borrow an analogy Meredith Nettles from Columbia University gave to The Washington Post).
Time Magazine reporting the Canadian Arctic permafrost is thawing 70 years earlier than expected. I mean at a rate shocking a group of scientists. All who released the findings of their long-term study this month.
A research team affiliated with the University of Alaska Fairbanks. It observed three sites over a period of 13 years between 2003 and 2016, according to a brief of their findings. Researchers discovered that a series of unusually warm summers. All that triggered the rapid thawing, which is occurring 150 to 240 percent above the average rate between 1979 to 2000.
Bill Cable, a co-author of the study and engineer at the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Germany. They tell TIME that the primary purpose of the research was to gather baseline measurements. All in those areas that didn’t have any data regarding permafrost. While Cable didn’t join the project until 2008, he said that no one anticipated finding the results that they did.
All wrapped up though by Nature Communiications too on permafrost:
Permafrost warming has the potential to amplify global climate change. All because when frozen sediments thaw it unlocks soil organic carbon. Yet to date, no globally consistent assessment of permafrost temperature change has been compiled. Here we use a global data set of permafrost temperature time series from the Global Terrestrial Network for Permafrost to evaluate temperature change across permafrost regions for the period since the International Polar Year (2007–2009). During the reference decade between 2007 and 2016, ground temperature near the depth of zero annual amplitude in the continuous permafrost zone increased by 0.39 ± 0.15 °C.
In conclusion and over the same period, discontinuous permafrost warmed by 0.20 ± 0.10 °C. Permafrost in mountains warmed by 0.19 ± 0.05 °C and in Antarctica by 0.37 ± 0.10 °C. Globally, permafrost temperature increased by 0.29 ± 0.12 °C. The observed trend follows the Arctic amplification of air temperature increase in the Northern Hemisphere.
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