The National Oceanic and Atmospheric Administration (NOAA) has a nice article that shows how people make their predictions. [1] As for me, up to now I have been looking at the 30 year trend rather then 10 years. Unless any one has a good argument why this is "wrong" I have no reason to change that...
To answer your question, looking at the trend on your website [2] I fully expect it will be "normal" to have no ice in the arctic in the summer months by 2050. It is not unreasonable to expect that there will be a summer well before then, when it will be possible to sail to the North pole.
I have no idea where you are going with the "negative feedback" part. Clearly there is a trend in sea ice loss in the arctic (both extend and volume) [3 so even if there is a negative feedback (and there could well be several) it is overshadowed by the warming. [4]
If you define ice free as zero ice and summer as june 21-sept 21, it's highly unlikely. There will always be a spot with some ice.
There will be enough open water and thin ice to make shipping and resource extraction practical within the next 30-50 years.
Of course, if you beleive your eminent russian astrophicisist, we're heading for a mini ice age, so you can't have it both ways.
In the summer, less ice means that the ocean can absorb sunlight and is exposed to air that averages above freezing. How did lack of insulation cause ocean cooling?
we're in a cooling cycle of the world now which is normal. last 7 yrs have given us the lowest temps in the last 100 yrs. artic ice has increased 50% in the last 2 yrs. man has never and will never be able to alter the earth's weather. we don't have the power.
Never because it is very cold in the Arctic.
yes...still thinking...I took this quite negatively actually!!! no idea!!!
As things are going right now, never.
I have noticed that when there is a big ice melt or in the case of 2012 ice destroyed by cyclones, that the proceeding ice freeze is much faster and greater, probably because the summer ice loss has let the ocean cool down through lack of insulation, this could be thought of as a negative feedback.
http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent_L.png
