Comments on: An Update on the Arctic Sea Ice

By: Marco

Marco — Tue, 12 Sep 2017 06:44:10 +0000

Thanks for the personal story, nonetheless!

Anecdotal stories are always to be taken with healthy scepticism, but at the same time they can be extremely powerful in conveying the reality “on the ground”.

By: northierthanthou

northierthanthou — Tue, 12 Sep 2017 02:58:30 +0000

It’s interesting. Around Barrow, the ice seemed relatively stable last year. I’ve seen it go out from the shore several times in the last seven years, and sometimes folks will deem it too dangerous to go out on. Elders say the ice is getting progressively thinner, and harder to predict. Last year, the whaling crews were still out on the ice when I left town on May 5th, which seems pretty good. That said, one crew had a lot of trouble getting a big bowhead up on the ice. It kept breaking under the carcass. So, the thinning theme wasn’t entirely absent from the ice.

…all very anecdotal of course, but I couldn’t help thinking abut these things when I stumbled across this post.

By: Stuart Bogle

Stuart Bogle — Mon, 19 Jun 2017 22:25:09 +0000

This was a very enlightening article and I enjoyed learning about how positive feedback is negative. I had no idea. The ice is melting at a staggering rate and the fact that it has reached a low point in history should make it clear to the nonbelievers that this is real.

By: StevoR

StevoR — Wed, 12 Apr 2017 12:34:47 +0000

This is caused by warm air and water, and it contributes to global warming. The more ice on the sea for longer, during the northern Summer, reflects away a certain amount of sunlight. With less ice, less sunlight is reflected away. This is called a “positive feedback” but it is not a “positive” thing. It is a negative thing. (But it is not a “negative feedback,” that’s something different!)

This is why I think we should use the terms escalating feedback instead of positive feedback and returning / equilibriumising / restorative feedback instead of negative feedback.

Great article, grim reality, here.

By: Jeff Harvey

Jeff Harvey — Sun, 09 Apr 2017 10:54:53 +0000

Bernard, you will love this paper. I don’t want to blow my own trumpet metaphorically but its really a bombshell, the culmination of over a year’s worth of effort. As soon as we get it published, you will know all about it.

By: Bernard J.

Bernard J. — Sat, 08 Apr 2017 15:50:30 +0000

Jeff, I am very curious…

By: Jeff Harvey

Jeff Harvey — Sat, 08 Apr 2017 08:14:40 +0000

Greg, FYI I have just written a paper for a major journal detailing Arctic ice extent and effects on biodiversity. I have some very prominent co-authors on it. I won’t let the cat out of the bag yet but as soon as we know its fate you will know about it and like what we have written.

By: Greg Laden

Greg Laden — Thu, 06 Apr 2017 22:55:58 +0000

Jim: absolutely.

By: Jim Hunt

Jim Hunt — Thu, 06 Apr 2017 21:56:13 +0000

Greg – Sea ice area is obviously the relevant metric if you’re considering albedo, but when I studied physics the “amount” of a substance implied “mass” or “volume”. That’s also the relevant number if you’re considering melting of the remaining ice.

Melting 10 meter thick ice takes a lot more energy than melting the same area of 1 meter thick ice!

By: Greg Laden

Greg Laden — Thu, 06 Apr 2017 16:08:25 +0000

Yes, the meaning of Antarctic vs. Arctic is huge. They are two very very different systems and have vastly different influences on climate. The antarctic does not lose significant albedo when sea ice is lacking because there are more glaciers in the southern hemisphere serving that purpose, etc.

The two ends of the earth are polar opposites in more ways than one!

And, yes, over the last year+, the Antarctic has had less ice formation, faster melting, and also, by the way, above freezing surface temperatures in places and times not seen before, so some of the land glaciers that normally only melt at the margins and from the sea itself are now subject to surface melting.