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Author Topic: Relative importance of ice based indicators  (Read 2280 times)

Paddy

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Relative importance of ice based indicators
« on: May 20, 2015, 04:21:56 PM »
I'm basically an only moderately well-informed amateur on this topic.  I'm aware of five main things to track in terms of the world's ICE:

Arctic sea ice, trackable by area, extent, or mass (trending downwards)
Antarctic sea ice, trackable by area, extent, or mass (trending upwards)
Greenland ice sheet, trackable by mass (trending downwards)
Antarctic ice sheet, trackable by mass (trending downwards)
Glaciers worldwide, trackable by mass (trending downwards)

How would people rank these in terms of importance?  I'd be tempted to put the AIS first as the single greatest amount of ice, followed by the Greenland ice sheet, arctic sea ice, antarctic sea ice, and finally glaciers worldwide, but I'm sure there are other interpretations.  Also, am I missing anything important?  (Permafrost, maybe?)

wili

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Re: Relative importance of ice based indicators
« Reply #1 on: May 20, 2015, 04:35:27 PM »
Importance for what? Determining slr?
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

Paddy

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Re: Relative importance of ice based indicators
« Reply #2 on: May 20, 2015, 04:40:42 PM »
Importance as indicators of the rate of climate change, primarily.

(Obviously, they are also important in terms of the specific things they predict, such as: access to sea routes in the case of arctic sea ice; sea level in the case of Greenland or Antarctic ice sheets; and fresh water supplies in the case of glaciers; but that's a more complicated question).

EDIT: Also, what is slr?  Sorry!

EDIT 2: Also, has there been any attempt to estimate a global mass balance trend for ice?
« Last Edit: May 20, 2015, 04:46:48 PM by Paddy »

Tor Bejnar

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Re: Relative importance of ice based indicators
« Reply #3 on: May 20, 2015, 05:22:18 PM »
I don't know if I'm informed or not, but the Antarctic ice sheet is usually tracked as two entities, the East Antarctic ice sheet (fairly stable) and the West Antarctic ice sheet (declining).
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How would people rank these in terms of importance?
This depends on what you are interested in.  Here are some possible 'most important':
Sea level rise (slr) this century - Greenland and West Antarctica
Sea level rise (slr) over 2,000 years - all 3 ice sheets
Global air temps this century - Arctic sea ice extent
Deny climate change - Antarctic sea ice winter extent  ;D
« Last Edit: May 20, 2015, 06:54:23 PM by Tor Bejnar »
Arctic ice is healthy for children and other living things.

pikaia

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Re: Relative importance of ice based indicators
« Reply #4 on: May 20, 2015, 05:48:34 PM »
I would say that they are all poor proxies for the rate of climate change (especially Antarctic sea ice). Direct measurements of climate, particularly temperature but also rainfall and wind, are all that matter.

Paddy

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Re: Relative importance of ice based indicators
« Reply #5 on: May 21, 2015, 09:16:45 PM »
I don't know if I'm informed or not, but the Antarctic ice sheet is usually tracked as two entities, the East Antarctic ice sheet (fairly stable) and the West Antarctic ice sheet (declining).

Yep, what I've seen meshes with that - it shows a wide variation by region, although overall it's losing something close to 100 gigatonnes of ice a year.

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Deny climate change - Antarctic sea ice winter extent  ;D

Heh :-)

I would say that they are all poor proxies for the rate of climate change (especially Antarctic sea ice). Direct measurements of climate, particularly temperature but also rainfall and wind, are all that matter.

I hear you, but I've found arguing from ice loss to be a powerful counter to those who doubt the temperature data.