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26-08-2016, 21:02
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#3017
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Registered User
Join Date: May 2008
Location: puɐןsuǝǝnb 'ʎɐʞɔɐɯ
Boat: Nantucket Island 33
Posts: 4,864
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Quote:
Originally Posted by Lake-Effect
No, you can say Greenland lost 0.74% of its present ice sheet in the last century, but you have no basis for saying the rate of ice loss is 0.74% per century, and it's counterintuitive, to boot.
...F. See me after class.
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What's the correct answer then teacher?
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27-08-2016, 03:37
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#3018
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Registered User
Join Date: Jul 2011
Location: USA
Posts: 1,006
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
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27-08-2016, 03:50
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#3020
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Moderator Emeritus
Join Date: Feb 2014
Location: Seville London Eastbourne
Posts: 13,406
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Quote:
Originally Posted by Lake-Effect
No, you can say Greenland lost 0.74% of its present ice sheet in the last century, but you have no basis for saying the rate of ice loss is 0.74% per century, and it's counterintuitive, to boot.
...F. See me after class.
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What's the correct answer then teacher?
************************************************** **
I think he just told you....
__________________
- Never test how deep the water is with both feet -
10% of conflicts are due to different opinions. 90% by the tone of voice.
Raise your words, not your voice. It is rain that grows flowers, not thunder.
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27-08-2016, 05:37
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#3021
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Registered User
Join Date: May 2008
Location: puɐןsuǝǝnb 'ʎɐʞɔɐɯ
Boat: Nantucket Island 33
Posts: 4,864
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
See, because I didn't actually state the loss was 0.74% last century, but simply projected the 270 Gt most recent annual loss guesstimate forward. I just assumed our esteemed forumite was misrepresenting - err sorry, misinterpreting - my numbers.
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27-08-2016, 06:55
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#3022
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Registered User
Join Date: May 2011
Location: Lake Ont
Posts: 8,547
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Quote:
Originally Posted by Reefmagnet
See, because I didn't actually state the loss was 0.74% last century, but simply projected the 270 Gt most recent annual loss guesstimate forward. I just assumed our esteemed forumite was misrepresenting - err sorry, misinterpreting - my numbers.
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You know what? I did screw up.
You said
Quote:
At this rate Greenland is losing 0.74% [o]f its present ice sheet volume per century
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... I failed to process the word "present", which makes your estimate exactly as you say above. So, sorry for that.
Notwithstanding, projecting the same century loss forward is not exactly good modelling. Why not the loss in last 50 years? the last 10? That would be more realistic.
Even if there's no temperature increase after today, various effects such as loss of ice mass, meltwater flow, uncovering of landmass, warming and change of ocean currents will all lead to accelerated melt rates.
And most of us know the temperature is still increasing.
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27-08-2016, 07:04
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#3023
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Registered User
Join Date: May 2008
Location: puɐןsuǝǝnb 'ʎɐʞɔɐɯ
Boat: Nantucket Island 33
Posts: 4,864
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Quote:
Originally Posted by Lake-Effect
You know what? I did screw up.
You said
... I failed to process the word "present", which makes your estimate exactly as you say above. So, sorry for that.
Notwithstanding, projecting the same century loss forward is not exactly good modelling. Why not the loss in last 50 years? the last 10? That would be more realistic.
Even if there's no temperature increase after today, various effects such as loss of ice mass, meltwater flow, uncovering of landmass, warming and change of ocean currents will all lead to accelerated melt rates.
And most of us know the temperature is still increasing.
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If the ice sheet is at -30 C then warming it to -28 or even -20 won't make it melt. Most of the melting is limited to a very small area compared to the island as a whole. Just more doomin' and gloomin'.
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27-08-2016, 07:41
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#3024
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Registered User
Join Date: May 2011
Location: Lake Ont
Posts: 8,547
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Quote:
Originally Posted by Reefmagnet
If the ice sheet is at -30 C then warming it to -28 or even -20 won't make it melt.
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Takes less energy to melt ice at -20 C than ice at -30 C.
Quote:
Most of the melting is limited to a very small area compared to the island as a whole.
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Meltwater flows... conducting heat, undercutting, etc etc. There's been lots written about it. You'd dispel more doom'n'gloom with better modeling. In fact, the skeptic argument in general would prevail if they simply provided a better model than the ones supporting the pro-AGW view.
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27-08-2016, 08:36
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#3025
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Registered User
Join Date: Jul 2011
Location: USA
Posts: 1,006
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Greenland ice sheet | Wikipedia
Quote:
Many scientists who study the ice melt in Greenland consider that a two or three degrees C temperature rise would result in a complete melting of Greenland’s ice.[5]...
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Quote:
If the entire 2,850,000 km3 (684,000 cu mi) of ice were to melt, global sea levels would rise 7.2 m (24 ft).[2] Recently, fears have grown that continued climate change will make the Greenland Ice Sheet cross a threshold where long-term melting of the ice sheet is inevitable. Climate models project that local warming in Greenland will be 3 °C (5 °F) to 9 °C (16 °F) during this century. Ice sheet models project that such a warming would initiate the long-term melting of the ice sheet, leading to a complete melting of the ice sheet (over centuries), resulting in a global sea level rise of about 7 metres (23 ft).[6] Such a rise would inundate almost every major coastal city in the world. How fast the melt would eventually occur is a matter of discussion. According to the IPCC 2001 report,[2] such warming would, if kept from rising further after the 21st Century, result in 1 to 5 meter sea level rise over the next millennium due to Greenland ice sheet melting. Some scientists have cautioned that these rates of melting are overly optimistic as they assume a linear, rather than erratic, progression. James E. Hansen has argued that multiple positive feedbacks could lead to nonlinear ice sheet disintegration much faster than claimed by the IPCC. According to a 2007 paper, "we find no evidence of millennial lags between forcing and ice sheet response in paleoclimate data. An ice sheet response time of centuries seems probable, and we cannot rule out large changes on decadal time-scales once wide-scale surface melt is underway."[11]...
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27-08-2016, 08:41
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#3026
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Marine Service Provider
Join Date: Aug 2006
Location: La Paz, Mexico
Boat: 1978 Hudson Force 50 Ketch
Posts: 3,920
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
I've been gone a day...did I miss anything?
Did the sea levels rise while I was away or the ice caps melt away killing the baby polar bears?
__________________
Rich Boren
Cruise RO & Schenker Water Makers
Technautics CoolBlue Refrigeration
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27-08-2016, 09:02
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#3027
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Senior Cruiser
Join Date: Sep 2014
Location: puget sound washington
Boat: 1968 Islander bahama 24 hull 182, 1963 columbia 29 defender. hull # 60
Posts: 12,113
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Quote:
Originally Posted by SailOar
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OK let's see here the quoted says local
Quote
Climate models project that local warming in Greenland will be 3 °C (5 °F) to 9 °C (16 °F) during this century. End quote.
Causing meltion of the ice sheet over centuries.
Quote
Ice sheet models project that such a warming would initiate the long-term melting of the ice sheet, leading to a complete melting of the ice sheet (over centuries),
End quote
So to summarize. The temp rise is projected to be a local event and the ice to melt over centuries. I'm sure the human race will be able to adapt to the estimated rise in sea levels in that time
Look what adaptive advances we have made in the last single century.
__________________
Non illigitamus carborundum
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27-08-2016, 14:32
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#3028
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Registered User
Join Date: May 2011
Location: Lake Ont
Posts: 8,547
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Quote:
Originally Posted by newhaul
I'm sure the human race will be able to adapt to the estimated rise in sea levels in that time.
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Me too.
We can also engage in a little bit better resource management now, so that maybe the melt will be a bit slower, and oil will last a bit longer.
Why can't we do both?
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27-08-2016, 14:38
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#3029
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Marine Service Provider
Join Date: Aug 2006
Location: La Paz, Mexico
Boat: 1978 Hudson Force 50 Ketch
Posts: 3,920
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Quote:
Originally Posted by Lake-Effect
Me too.
We can also engage in a little bit better resource management now, so that maybe the melt will be a bit slower, and oil will last a bit longer.
Why can't we do both?
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Now that's a little disingenuous because if the MMGWC had their way there would be no burning of carbon fuels. Not for cars, power plants or pagan festivals.
__________________
Rich Boren
Cruise RO & Schenker Water Makers
Technautics CoolBlue Refrigeration
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27-08-2016, 14:42
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#3030
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Registered User
Join Date: May 2008
Location: puɐןsuǝǝnb 'ʎɐʞɔɐɯ
Boat: Nantucket Island 33
Posts: 4,864
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Re: Do we need to be preparing for Arctic cruising strategies because of Global Cooli
Quote:
Originally Posted by Lake-Effect
Takes less energy to melt ice at -20 C than ice at -30 C.
Meltwater flows... conducting heat, undercutting, etc etc. There's been lots written about it. You'd dispel more doom'n'gloom with better modeling. In fact, the skeptic argument in general would prevail if they simply provided a better model than the ones supporting the pro-AGW view.
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No model required. Hollywood physics don't apply in the real world.
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