In February, 1940 near-polar sea ice was two metres thick.
23 Feb 1940 – THE NORTH POLE. Is it Getting Warmer. | BUNDABER…
Seventy five years later, the Navy reports that near-polar Arctic sea ice is two metres thick.
There has been no net change in the thickness of Arctic sea ice for 75 years. Government experts call it a “death spiral.”
Don’t forget the voyages of the St. Roch (Pronounced Rock) through the Arctic in the 1940s.
Stumbled just on this
http://neven1.typepad.com/blog/2015/03/thinner-and-thinner.html
Just how thin it can be??
I’ve seen a lot of posts on the StevenGoddard blog about Arctic ice in recent weeks, but there seems to be no mention of Antarctic ice.
To correct for this hemisphere bias, here are some photos of glacier extents in 1920.
http://imgur.com/gallery/6hHp4
According to the photos the glaciers in Antarctica were bigger in 1920s than today.
That doesn’t imply any particular cause, of course.
As it is quite rare for anywhere in Antarctica (except for the peninsula) to be above 0C, surface warming doesn’t seem likely. A change in circumpolar wind patterns which decreased deposition rate over land, or increased sublimation, leading to thinner glaciers that melt quicker at the sea, seems more likely, but requires assuming wind patterns changed.
The bedrock of West Antarctica is below sea level due to the sea level rise at the start of the Holocene 12,000 years ago (it was above sea level before then).
What happens to ice when the rock its sitting on is below sea level and the sea surrounds it?
Hint: It has nothing to do with CO2
Clue number 2: all the ice in West Antarctica which is below sea level, which is much of it, will not raise sea level when it melts. Only ice above sea level can do that.
This is something the Causa Nostra forgets to mention.
Hey SG/Tony,
I have found another failed Arctic ice prediction for you to add to the archives, this time from Greenpeace. My emphasis:
Nov 2008 + 5 years was Nov 2013. I have done the comparison with the UIUC’s Arctic ice measurements. See comparison diagram here: http://i.imgur.com/xANTMuL.png
You may host a copy of that for your website if you wish.
Of course Greenpeace are advocates of recycling. Interesting that Greenpeace was happy to “recycle” the doomsayer forecast of an Arctic summer ice “death spiral” even after data had already become available showing the 2008 minimum was not on the forecast DeathSpiral™ line.
Mantra over measurement.
Meanwhile there’s currently a full house of ?Arctic? ?sea ice? metrics at lowest ever levels for the date:
http://GreatWhiteCon.info/2015/03/arctic-sea-ice-area-lowest-ever/
By way of just one example, here’s how your favourite (and deprecated!) DMI 30% extent looks at the moment:
http://greatwhitecon.info/wp-content/uploads/2015/03/DMI-30-icecover_20150308.png
.
Wanna bet when the arctic ice is gone? I’d say there is more arctic sea ice in 2025 measured in extent.