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DavidR

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Hansens predictions for Future Ice
« on: May 04, 2016, 01:50:21 PM »
Original quote re Hansen by ktonine on the IJIS thread.
"If I'm not mistaken, this is essentially what Hansen has predicted - short-term global cooling as a result of global warming, thanks to melting Greenland. Predictions Implicit in “Ice Melt” Paper and Global Implications:"



I think what Hansen's study misses is what's implicit if the anomalies he projects are realized. The 2080-2100 image is more dramatic and, IMO, the departures it shows would be sufficient to allow ice sheets to begin regrowing across NRN Europe and NRN North America (which is not mentioned in his papers).
<snippage>
Ice sheets? Nonsense. That's a HUGE stretch.  Actually it's not a stretch; energetically, its unreachable.  The forcing from CO2 is already too high, the increased albedo from open arctic water will provide far and away additional capture heat to render it impossible.  Very functionally, the ice sheets grew in part because there was an Arctic ice pack to aid in bouncing heat back out of the hemisphere.  I think you are absurdly overestimating the effect of the feedback from Greenland melt.

I don't know about that. I think Quebec would be insulated from the warmer Arctic Ocean by the freshwater streaming south through the CAA that originates in Greenland/summer melt. This was visible last year as sea ice, for the first time in satellite history, advanced into Hudson Bay from the northeast, rather than forming on the shore from the west and building east.

The projections from Hansen are very dramatic (below -- 2065, 2080, 2096). I don't think it is unreasonable that a little tweaking of output could yield a yearly temp decrease of 5C or more in places like Quebec and despite increased GHG forcing I think that *IF* the kind of anomalies projected by Hansen due to melt are indeed realized, ice sheets would reform.

http://www.columbia.edu/~jeh1/2015/20150704_IceMelt.pdf

It should also be noted that the speed with which we get from a small area of - anomalies to a huge one is VERY fast. The changes projected between 2065 and 2096 are enormous! And given today's maps are already beginning to look like output for the mid 20th century (and the fact that Hansen has said they underestimate sensitivity), we may already be off the cliff.
This thread is for discussions related to  James Hansen's predictions that  have been erroneously discussed on the IJIS thread. Please continue the discussion here.  Thank you
« Last Edit: May 06, 2016, 07:18:32 AM by DavidR »
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Buddy

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Re: Hansens predictions for Future Ice
« Reply #1 on: May 04, 2016, 02:33:24 PM »
This is for user bbr2314 from the IJIS string  Below...is bbr2314's statement recently:

Quote
This is a bit wackadoo, but a silly theory: perhaps an ice-free Arctic Ocean is in fact the turning point between warming and ice ages? If an ice-free Arctic leads to Greenland being used more efficiently as a heat sink, the combination of that + freshwater melt wouldn't necessarily make North America much colder in the winter, but summers could become nonexistent over Quebec/Hudson Bay as well as northern Europe/Russia due to the effects of AMOC shutdown on other side of the pond (and a perma-LP SE of Greenland that also delivers low-level cold to Europe).

Once the Arctic becomes ice-free, continental ice sheets begin expanding due to effects of Greenland + remaining mountain-based ice sheets, but the Arctic Ocean remains a heat sink during this time, as ice sheets do not grow quickly. This would happen region by region, not all at once, as we seem to now be seeing in Quebec.

Just a thought...
I think that is MORE THAN A BIT WACKADO of an idea.  The earth is a "somewhat enclosed" system.  It will be "in balance" when the energy COMING IN.....EQUALS THE ENERGY GOING OUT.

Even if we stopped putting CO2 into the atmosphere right now......many of the various feedback effects which we have ALREADY STARTED, would still need decades or centuries to continue to play themselves out.  We're NOWHERE NEAR turning this puppy around.

There is NO WAY that the melting of the Arctic is someway going to "turn us around" towards another ice age.  I generally try to be "measured" in my responses......and right now I am having a hard time preventing myself from typing something like:

That is the most ridiculous thing I have read on this site.

OK....I couldn't help myself.  Sorry.  I enjoy READING and LEARNING from the many varied people and backgrounds on this site.  But your idea is something that I would expect to hear from Donald Trump (and no....that is NOT a compliment:).

     
« Last Edit: May 04, 2016, 02:53:08 PM by Buddy »
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crandles

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Re: Hansens predictions for Future Ice
« Reply #2 on: May 04, 2016, 02:37:23 PM »
New ice sheets seems a stretch. Snow and ice lasting an extra month before melting would be significant let alone lasting though year. New and growing glaciers in Norwegian mountains might be possible but there wouldn't be huge populations being severely affected.

Still I was wondering if large temp differences would drive storms resulting in more snow precipitation which together with cold regional temperatures might limit melt so changing Greenland mass balance such that this might limit the growth of those cold spots before they grew that large and intense.

I don't have any expertise and this is just speculation. Therefore interested to hear what more knowledgeable people think.

Nick_Naylor

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Re: Hansens predictions for Future Ice
« Reply #3 on: May 04, 2016, 06:09:55 PM »
What happens to seawater mixing and SST's during ice-free late-summer conditions?

Without a firm grasp of all the consequences, it would seem that the surface layer would rapidly heat, since the albedo would drop and there would no longer be a floating ice pack in place to remove heat unless there was a major increase in mixing. And with that, atmospheric temps would rise as well - followed by a more rapid cooling in October than humanity has ever experienced.

Then again, the warmer SST's might lead to more humidity and a tendency toward cloudy weather patterns.

I'm pretty sure most of us will get to see this unfold in real life before too many more years go by.

jdallen

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Re: Hansens predictions for Future Ice
« Reply #4 on: May 04, 2016, 08:10:47 PM »
What happens to seawater mixing and SST's during ice-free late-summer conditions?

Without a firm grasp of all the consequences, it would seem that the surface layer would rapidly heat, since the albedo would drop and there would no longer be a floating ice pack in place to remove heat unless there was a major increase in mixing. And with that, atmospheric temps would rise as well - followed by a more rapid cooling in October than humanity has ever experienced.

Then again, the warmer SST's might lead to more humidity and a tendency toward cloudy weather patterns.

You summarize my objections to the idea pretty well.  Because of that, I think that the Laurentide region of Canada cooling enough to maintain a permanent snow pack to be a virtual impossibility.   The total heat in the system is increasing massively beyond what it was during the ice ages and continues to rise rapidly.   

CO2 is also much to high.  The Vostok cores are pretty definitive about this:

http://earthguide.ucsd.edu/virtualmuseum/images/raw/CCC_Fig4_3_2.jpg

Conditions which produced the continental ice sheets required CO2 to literally be *half* of what it is currently.  Otherwise, GHG forcing retains enough heat to prevent them from being established.  Slower weather system changes caused by the Atlantic conveyor slowing down notwithstanding, (...that will happen in part because of massively increased heat north of 45 degrees latitude), heat will still flow into the region in greater amount than it did then, or does now.

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bbr2314

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Re: Hansens predictions for Future Ice
« Reply #5 on: May 04, 2016, 09:31:31 PM »
This is for user bbr2314 from the IJIS string  Below...is bbr2314's statement recently:

Quote
This is a bit wackadoo, but a silly theory: perhaps an ice-free Arctic Ocean is in fact the turning point between warming and ice ages? If an ice-free Arctic leads to Greenland being used more efficiently as a heat sink, the combination of that + freshwater melt wouldn't necessarily make North America much colder in the winter, but summers could become nonexistent over Quebec/Hudson Bay as well as northern Europe/Russia due to the effects of AMOC shutdown on other side of the pond (and a perma-LP SE of Greenland that also delivers low-level cold to Europe).

Once the Arctic becomes ice-free, continental ice sheets begin expanding due to effects of Greenland + remaining mountain-based ice sheets, but the Arctic Ocean remains a heat sink during this time, as ice sheets do not grow quickly. This would happen region by region, not all at once, as we seem to now be seeing in Quebec.

Just a thought...
I think that is MORE THAN A BIT WACKADO of an idea.  The earth is a "somewhat enclosed" system.  It will be "in balance" when the energy COMING IN.....EQUALS THE ENERGY GOING OUT.

Even if we stopped putting CO2 into the atmosphere right now......many of the various feedback effects which we have ALREADY STARTED, would still need decades or centuries to continue to play themselves out.  We're NOWHERE NEAR turning this puppy around.

There is NO WAY that the melting of the Arctic is someway going to "turn us around" towards another ice age.  I generally try to be "measured" in my responses......and right now I am having a hard time preventing myself from typing something like:

That is the most ridiculous thing I have read on this site.

OK....I couldn't help myself.  Sorry.  I enjoy READING and LEARNING from the many varied people and backgrounds on this site.  But your idea is something that I would expect to hear from Donald Trump (and no....that is NOT a compliment:).

     

Using caps lock repeatedly throughout your post would make you seem to be the Donald Trump here, no?

Of course it will be in balance when the energy coming in equals the energy coming out; the albedo effect is perhaps the single most important factor when it comes to this, and is why it could overwhelm the (admittedly enormous) +GHG signal that humans have created.

Nick Naylor actually describes something that happened (rapidly cooling October) in several recent years in the US, most notably the sea ice minimums of 2011/12, which saw NYC's snowiest October on record and its earliest 4"+ storm on record (a few days into November in 2012).

While conditions that previously created the ice-sheets had much lower CO2 concentrations, Hansen's research would imply surface temperatures cold enough to allow ice-sheet regeneration in many regions. His research needs only be a little bit wrong for the cold to expand west into Quebec/Hudson Bay as well.

Why is it that Quebec is the only polar region with substantial and consistent +++ snowfall departures??

I would argue that low-level cold air emanating from Greenland & AMOC shutdown is becoming sufficient to overwhelm the +GHG signal in certain regions (like Hudson Bay and Quebec, as well as northern Europe) which is why these are the only polar regions with any apparent cooling.

It should also be noted that despite significant melt occurring in April, there was no volume decrease on DMI. This goes to show that the absolute change year over year is, IMO, being overlooked. Greenland losing mass as a whole is bad, but if precipitation on Greenland is increasing, then the total amount of yearly freshwater Greenland is unleashing on the NATL is going to be increasing much more than predicted, and ice gained while ice is lost does not take away the freshwater runoff into the NATL. Perhaps this is why the models are not account for how quickly these changes seem to be appearing?

If Hansen is right, then some areas see a 20 degree C decrease in annual temperatures in the span of 30 years. That is about as bad as nuclear winter. And it affects all of Europe and much of North America.

« Last Edit: May 04, 2016, 09:37:43 PM by bbr2314 »

bbr2314

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Re: Hansens predictions for Future Ice
« Reply #6 on: May 04, 2016, 09:49:12 PM »
It should be noted that Hansen's 2096 map would also imply sea ice over much of the North Atlantic, stretching from Greenland to the UK. At least per my rough look at avg temps in that area vs what he predicts.

jdallen

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Re: Hansens predictions for Future Ice
« Reply #7 on: May 04, 2016, 11:17:17 PM »
It should be noted that Hansen's 2096 map would also imply sea ice over much of the North Atlantic, stretching from Greenland to the UK. At least per my rough look at avg temps in that area vs what he predicts.
bbr2314, with respect, I find your interpretation of Hansen infuriatingly naive.  I'll grant you some slack, because early on in these forums, I committed that kind of sin once or twice myself.

Rough look is *right*.  Please dig in a bit more deeply.   I'm also very keen to see where you find Hansen's work predicting a 20C *drop* in regional temperatures anywhere.  Color me skeptical, but I don't think you'll be able to find a valid reference.
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bbr2314

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Re: Hansens predictions for Future Ice
« Reply #8 on: May 04, 2016, 11:23:22 PM »
It should be noted that Hansen's 2096 map would also imply sea ice over much of the North Atlantic, stretching from Greenland to the UK. At least per my rough look at avg temps in that area vs what he predicts.
bbr2314, with respect, I find your interpretation of Hansen infuriatingly naive.  I'll grant you some slack, because early on in these forums, I committed that kind of sin once or twice myself.

Rough look is *right*.  Please dig in a bit more deeply.   I'm also very keen to see where you find Hansen's work predicting a 20C *drop* in regional temperatures anywhere.  Color me skeptical, but I don't think you'll be able to find a valid reference.

The map I posted in the previous post I made has his projections...

jdallen

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Re: Hansens predictions for Future Ice
« Reply #9 on: May 04, 2016, 11:42:55 PM »
You posted images.  What was the source?  What paper did they come from? Where's the supporting research?  You have images, but  no context.

Here's NOAA's projections for the 2050's, based on model runs and research they've performed.  Link to their reference page follows.

http://www.gfdl.noaa.gov/pix/user_images/kd/highlights/GFDL_CM2p1_GlobalSfcTemp_ANN_A1B_kd_1920x1163.png

http://www.gfdl.noaa.gov/patterns-of-greenhouse-warming-ar4
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AmbiValent

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Re: Hansens predictions for Future Ice
« Reply #10 on: May 04, 2016, 11:57:47 PM »
I think this prediction suffers from oversimplification of a complex system. To get to these results, you'd have to first accept an extremely fast sea level rise by 5 meters, most of it within 2 decades. I don't think it should be rejected because of Palmstroem's law ("what must not be, cannot be"), but it needs to be checked by using a less simplified system and looking whether those results still appear or are just an artifact.
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crandles

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Re: Hansens predictions for Future Ice
« Reply #11 on: May 05, 2016, 12:54:18 AM »

Rough look is *right*.  Please dig in a bit more deeply.   I'm also very keen to see where you find Hansen's work predicting a 20C *drop* in regional temperatures anywhere.  Color me skeptical, but I don't think you'll be able to find a valid reference.

See fig 6 on page 8 of http://arxiv.org/ftp/arxiv/papers/1602/1602.01393.pdf
So image shown above is from Hansen et al paper.

Caption says
Fig. 6. Surface air temperature (°C) relative to 1880-1920 in (a) 2065, (b) 2080, and (c) 2096. Top row is IPCC scenario A1B. Ice melt with 10-year doubling is added in other scenarios.

Maybe doubling 8 times ( (2096-2016)/10 ) over is somewhat speculative but the image shown is from the paper.

Thread is called "Hansens predictions for Future Ice" so it is the paper you should expect from the title.

Edit:
I assume scale on fig 6 going to -21C means -21C is the maximum cooling anomaly at a single point rather than there being regional cooling of 21C over some sizeable area. Still -21C is shown as the scale maximum in the paper.
« Last Edit: May 05, 2016, 01:54:47 AM by crandles »

ktonine

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Re: Hansens predictions for Future Ice
« Reply #12 on: May 05, 2016, 01:14:40 AM »
From the IJIS thread:


If I'm not mistaken, this is essentially what Hansen has predicted - short-term global cooling as a result of global warming, thanks to melting Greenland. Predictions Implicit in “Ice Melt” Paper and Global Implications:

Yes, but localized, and primarily a driver of extreme weather.  Elsewhere, things will still be a hot house.
Yes.  Not global.  edit   And, the cooling of the Southern ocean's surface is not so helpful as it might appear since "Antarctic freshwater-induced regional surface cooling yields amplifying feedbacks that melt ice shelves, which is the principal route to increased Antarctic ice sheet mass loss."   (sorry for the tangent - thought it was important to point that out)
I think what Hansen's study misses is what's implicit if the anomalies he projects are realized. The 2080-2100 image is more dramatic and, IMO, the departures it shows would be sufficient to allow ice sheets to begin regrowing across NRN Europe and NRN North America (which is not mentioned in his papers).

Perhaps the ensuing albedo feedback this causes in summer escalates/is amplified by +GHG and triggers runaway cooling as more and more solar energy is reflected at latitudes where insolation is much greater than in the Arctic? Additional water vapor could also allow much deeper wintertime snows in polar regions, also buffering against melt (and aiding freshwater input into oceanic current shutdown). This may explain why there are seemingly so few or very brief instances of an open Arctic Ocean in recent history; it would seem another series of feedbacks we do not yet fully understand kicks in once that happens.
Please show why you think that.  What research might lead you to disregard Hansen's work?
   ( probably needs moved to another thread )

(Neven - Please, move this to a more appropriate place?   Thank You)

It's been almost a year since I first read Hansen et al's "Ice Melt" paper, but I was pretty sure I hadn't misunderstood it.  But since there were several people that seemed to think so I went back and checked.  Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 ◦C global warming could be dangerous. Page 3771:

Quote
Global cooling continues for centuries for the case with freshwater forcing sufficient to shut down the AMOC (Fig. 11). If the forcing is only 0.5 m of sea level, the temperature recovers in a few decades. However, the freshwater forcing required to reach the tipping point of AMOC shutdown may be less in the real world than in our model, as discussed below. Global cooling due to freshwater input on the Southern Ocean disappears in a few years after freshwater input ceases (Fig. 11), for both the smaller (0.5 m of sea level) and larger (2.5 m) freshwater forcings.



My memory of the paper was correct, with large freshwater insertions from Greenland and/or Antarctica Hansen forecasts a drop in global temperature. They  re-emphasisze this point in their conclusions:

Quote
...our study suggests that global surface air temperature, although an important diagnostic, is a flawed metric of planetary “health”, because faster ice melt has a cooling effect for a substantial period.

But, this is only temporary - we're not going to see new ice-sheets spring up.  This can be seen in Figure 7a:



crandles

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Re: Hansens predictions for Future Ice
« Reply #13 on: May 05, 2016, 01:33:27 AM »

But, this is only temporary - we're not going to see new ice-sheets spring up.  This can be seen in Figure 7a:



I assumes that temporary drop in temperature is a result of SLR reaching 5m and then immediately stops completely as shown in Fig 5 at about 20552060 which seems to be the time of the peak of the temperature drop. Remove the cause of the cooling and the effect is going to drop out. That seems pretty unrealistic to me.
« Last Edit: May 05, 2016, 01:42:52 AM by crandles »

ktonine

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Re: Hansens predictions for Future Ice
« Reply #14 on: May 05, 2016, 02:05:56 AM »

But, this is only temporary - we're not going to see new ice-sheets spring up.  This can be seen in Figure 7a:



I assumes that temporary drop in temperature is a result of SLR reaching 5m and then immediately stops completely as shown in Fig 5 at about 20552060 which seems to be the time of the peak of the temperature drop. Remove the cause of the cooling and the effect is going to drop out. That seems pretty unrealistic to me.

Crandles - it's a very interesting and far reaching paper.  The counter-intuitive notion that global warming can cause regional cooling due to large freshwater melt is just one of many insights.  This happens despite an increase in CO2 and an increase in the energy budget deficit.  What Hansen et al propose is that the freshwater injection creates a lid essentially making the sub-surface oceans warmer, this keeps the melting going without an increase in surface temps.

As he states elsewhere - it's a tug-of-war between CO2 warming and mellt-ice cooling, and the cooling wins in the short run. But except in the case of a complete AMOC shutdown global warming eventually wins out.




bbr2314

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Re: Hansens predictions for Future Ice
« Reply #15 on: May 05, 2016, 02:15:39 AM »

But, this is only temporary - we're not going to see new ice-sheets spring up.  This can be seen in Figure 7a:



I assumes that temporary drop in temperature is a result of SLR reaching 5m and then immediately stops completely as shown in Fig 5 at about 20552060 which seems to be the time of the peak of the temperature drop. Remove the cause of the cooling and the effect is going to drop out. That seems pretty unrealistic to me.

But if the temperature drop halts Greenland warming (and freshwater output) because it is sufficiently cool enough, wouldn't that imply that there is widespread freezing going on, both in Greenland and elsewhere? And at some point, the albedo feedback from such a massive drop would develop legs of its own, possibly longer ones than +GHG forcing...

ktonine

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Re: Hansens predictions for Future Ice
« Reply #16 on: May 05, 2016, 02:31:24 AM »

But if the temperature drop halts Greenland warming (and freshwater output) because it is sufficiently cool enough, wouldn't that imply that there is widespread freezing going on, both in Greenland and elsewhere? And at some point, the albedo feedback from such a massive drop would develop legs of its own, possibly longer ones than +GHG forcing...

Global warming has not halted - the extra energy is put into the sub-surface waters - where they can still attack the ice from below.  Eventually the magnitude of the warming will overcome the initial cooling.   I assume this would be coincident with the sub-surface ice exposed to these warmer waters finally melting out.  Better to read the paper than get it all 2nd-hand from me.

crandles

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Re: Hansens predictions for Future Ice
« Reply #17 on: May 05, 2016, 02:32:03 AM »
A significant area cooling by 10C and melt from Greenland continuing to increase at exponential rate would appear sillier than SLR just stopping completely.

My reaction is that the more likely scenario is that the exponential increase in the melt volume stops growing so rapidly far earlier than when we reach large areas cooling by 10C? Or is such imbalance plausible? I am not sure I follow what the paper is arguing.

The paper says
Quote
Our sharp cut-off of melt aids separation of immediate forcing effects and feedbacks.

ie they are not claiming the sudden stop in fresh water flux is realistic.

Quote
Cooling from ice melt is largely regional, temporary, and does not alleviate concerns about
global warming. Southern Hemisphere cooling is mainly in uninhabited regions. Northern
Hemisphere cooling increases temperature gradients that will drive stronger storms (Sec. 3.8 ).
Global cooling due to ice melt causes a large increase in Earth’s energy imbalance (Fig. 7b),
adding about +2 W/m2, which is larger than the imbalance caused by increasing GHGs. Thus,
although the cold fresh water from ice sheet disintegration provides a negative feedback on
regional and global surface temperature, it increases the planet’s energy imbalance, thus
providing more energy for ice melt (Hansen, 2005). This added energy is pumped into the ocean.
 Increased downward energy flux at the top of the atmosphere is not located in the regions
cooled by ice melt. On the contrary, those regions suffer a large reduction of net incoming
energy (Fig. 8a). The regional energy reduction is a consequence of increased cloud cover (Fig.
8b) in response to the colder ocean surface. However, the colder ocean surface reduces upward
radiative, sensible and latent heat fluxes, thus causing a large (~50 W/m2) increase of energy into
the North Atlantic and a substantial but smaller flux into the Southern Ocean (Fig. 8c).

Guess I first need to read Hansen 2005 to follow what is being argued.

Post now seen while typing above
Quote
What Hansen et al propose is that the freshwater injection creates a lid essentially making the sub-surface oceans warmer, this keeps the melting going without an increase in surface temps.
Thanks for this. Is that what is in Hansen 2005?

ktonine

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Re: Hansens predictions for Future Ice
« Reply #18 on: May 05, 2016, 02:50:52 AM »
The paper says
Quote
Our sharp cut-off of melt aids separation of immediate forcing effects and feedbacks.

ie they are not claiming the sudden stop in fresh water flux is realistic.

Correct - they are doing a modeling exercise.  Then taking the model results, along with observational and paleo data, to make predictions for the future.  The best criticism of Hansen et al is that it relies upon a chain of hypotheses - any of which could be wrong. There's a lot of new ground being broken here at the edge of what we know (or beyond).  I find it interesting that they had to fix bad calculations in the GCM used and add new capabilities.  Entire papers have been written around what Hansen et al cover in a paragraph almost as an aside :)

I believe Hansen (2005) is probably a reference to Earth’s Energy Imbalance: Confirmation and Implications   The relevant paragraphs are probably at the end:

Quote
Implications. The thermal inertia of the ocean, with resulting unrealized warming “in the pipeline”, combines with ice sheet inertia and multiple positive feedbacks during ice sheet disintegration to create the possibility that the climate system could reach a point where large sea level change is practically impossible to avoid. If the ice sheet response time is millennia, the ocean thermal inertia and ice sheet dynamical inertia are relatively independent matters. However, it has been suggested, based on the saw-toothed shape of glacial-interglacial global temperature and qualitative arguments about positive feedbacks, that substantial ice sheet change could occur on the time scale of a century (25).

The destabilizing impact of comparable ocean and ice sheet response times is apparent. Say initial stages of ice sheet disintegration are detected. Before action to counter this trend could be effective it would be necessary to eliminate the positive planetary energy imbalance, now ~0.85 W/m2, which exists due to the ocean’s thermal inertia. Given energy infrastructure inertia and trends in energy use, that task could require of order a century. If the time for significant ice response is as short as a century, the positive ice-climate feedbacks imply the possibility of a system out of our control.

bbr2314

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Re: Hansens predictions for Future Ice
« Reply #19 on: May 05, 2016, 04:21:15 AM »
If the freshwater flux' sudden end is not realistic then doesn't that mean the cooling would continue (however sporadically) until melt either ceased because it got sufficiently cold or there was no ice left?

The presumption people seem to be making is that there is more heat entering the system than can be removed through negative feedbacks. And I would argue that if Hansen's research is accurate, YES, we are belching an unprecedented and truly catastrophic amount of change into the air. But it isn't all for the warmer, and the net disorder from a new cold pole centered on Greenland will add another layer of chaos to problems already occurring.

While the amount of forcing derived by GHG will be significant, would increasing summertime albedo in polar regions eventually be enough to negate/reverse this, even as the Arctic Ocean continues to warm? And perhaps that is the tipping point for the end of Greenland melt in a state that *isn't* completely devoid of ice?

If Hansen's model is correct we are very close to the max temp departure we will see prior to this effect kicking in more significantly (2065 is only expected to be +1.78C, only a few tenths warmer than today, with temps in 2080 falling to +1.11). Again, this does *not* mean Arctic amplification and its ensuing feedbacks will decrease -- if anything, this will aid the swings from massive ++ to massive -- departures many of us are increasingly seeing, at least before Greenland Winter arrives in full.

The below map has a strong semblance to what Hansen is showing. We already have the NATL cool pool.

I think what seems to happen in Hansen's model is that the pool in the Labrador Sea grows larger and larger, spilling E and SE until the Gulf Stream can no longer move North (and in ensuing years it begins expanding SW as well, shunting it further S off the East Coast than today).

Perhaps the leftover blob of salty pre-transition waters north of Europe ends up drifting into the Arctic Ocean itself, like we are seeing today in the Atlantic side of the Arctic, where salinity is *increasing* and 50F+ water was present last summer? 


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Re: Hansens predictions for Future Ice
« Reply #20 on: May 05, 2016, 06:17:03 AM »
bbr - the cold water blob does not block the GS - the GS continues under it.

Summertime albedo isn't going to increase.

As pointed out, the cooling is transitory - there is nothing like the necessary time frame for any sort of  substantive build up of snow, much less ice.  There is simply too much heat elsewhere in the system which would prevent it.  No -20C anomaly.  No impending shock freeze.

The "cool pool" only survives as long as there is ice in Greenland, at which point it, plus the "cold pole" disappears, possibly to reemerge seasonally over NE Siberia - the only place far enough north, and far enough away from any ocean to permit serious cold during midwinter.

That we will have areas that will cool I have no argument with.  That the "cool pool" could precipitate what amounts to a prompt reversal of AGW, I do have one.
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rboyd

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Re: Hansens predictions for Future Ice
« Reply #21 on: May 05, 2016, 06:30:19 AM »
Given the scale of extra energy intake from a summertime ice-free Arctic Ocean, plus loss of albedo on the melting Greenland ice sheet, would the impact of the cold pool not be counterbalanced for the Northern Hemisphere as a whole? There would be huge weather pattern changes given a warming arctic sea, the cold pool, and the warmth in the rest of the north atlantic, but perhaps not an overall cooling?

bbr2314

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Re: Hansens predictions for Future Ice
« Reply #22 on: May 05, 2016, 07:19:28 AM »
bbr - the cold water blob does not block the GS - the GS continues under it.

Summertime albedo isn't going to increase.

As pointed out, the cooling is transitory - there is nothing like the necessary time frame for any sort of  substantive build up of snow, much less ice.  There is simply too much heat elsewhere in the system which would prevent it.  No -20C anomaly.  No impending shock freeze.

The "cool pool" only survives as long as there is ice in Greenland, at which point it, plus the "cold pole" disappears, possibly to reemerge seasonally over NE Siberia - the only place far enough north, and far enough away from any ocean to permit serious cold during midwinter.

That we will have areas that will cool I have no argument with.  That the "cool pool" could precipitate what amounts to a prompt reversal of AGW, I do have one.

I did not say it would reverse AGW I said it could lead to ice sheets growing in the NHEM and cooling in some regions. Though perhaps the end result would be a reversal of AGW, at least in terms of its meaningful effects on the surface of the planet.

Thank you for pointing that out re: the GS. But I think the point you & others are missing here is that despite what is happening underneath the surface, the surface is what sensibly determines our weather; this is why the Hansen projections are so dramatic.

Re: summertime albedo -- even a switch from forest to grassland would represent an albedo increase, so snowcover is a much added bonus. Why wouldn't summertime albedo increase if the Arctic forests begin to burn? Grassland has a higher albedo than forest.

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Re: Hansens predictions for Future Ice
« Reply #23 on: May 05, 2016, 02:49:45 PM »
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Using caps lock repeatedly throughout your post would make you seem to be the Donald Trump here, no?

I use it for emphasis.....and my hands aren't small ;D

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Of course it will be in balance when the energy coming in equals the energy coming out; the albedo effect is perhaps the single most important factor when it comes to this, and is why it could overwhelm the (admittedly enormous) +GHG signal that humans have created.

So let's take a STEP BACK to take a  40,000 foot view....and think about what the major issues of physics at play:

1)  GHG are still high...and going higher (perhaps MUCH higher depending on how the feedback effects like permafrost and others continue to play out)....and when we get out "s***" together on policy.  And don't forget....we still have a filthy China and India that will be cleaning up their air over time....and that will INCREASE temps due to diminished amount of aerosol, which will allow energy from the sun to work on that growing level of GHG.

2)  We have more cool....fresh water being added to the ocean system from the current melting of Greenland ice sheet.  The effects of which are dependent on ocean currents (or the shut down of some of those currents as you note).

3)  We have more and more ice free ocean in the Arctic (currently).....at an earlier and earlier date with the passage of time over the next 10 - 20 years (until I see those change)

4)  We continue have a Greenland that has continued to LOSE albedo over the last decade....and that has NOT turned around as yet.  And unfortunately.....all that crappy looking coal dust and forest fire dust isn't going anywhere... much of it just keeps melting down and sitting on the top soaking up energy.  And there is STILL coal dust flying around for the foreseeable future (40 years AT LEAST) to provide an annual "topping"....not to mention increased forest fire "dust".

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Nick Naylor actually describes something that happened (rapidly cooling October) in several recent years in the US, most notably the sea ice minimums of 2011/12, which saw NYC's snowiest October on record and its earliest 4"+ storm on record (a few days into November in 2012).

I EXPECT snow storms in the northeast US to continue to be "nasty"....and BIGGER in coming 20 - 40 years.  More open ocean....more water vapor, etc.  A "snowiest October" on record IS what I would currently expect.  It's New York....not North Carolina.
 
 
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While conditions that previously created the ice-sheets had much lower CO2 concentrations, Hansen's research would imply surface temperatures cold enough to allow ice-sheet regeneration in many regions. His research needs only be a little bit wrong for the cold to expand west into Quebec/Hudson Bay as well.

Keep in mind.....his research can be wrong on EITHER SIDE of his expectations (could be surface temperatures not nearly as cold, which I am much more inclined to think would happen).

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Why is it that Quebec is the only polar region with substantial and consistent +++ snowfall departures??

It (Quebec the province) is surrounded on basically 80% of its borders by ocean (or the ocean is VERY CLOSE).  That is NOT surprising to me at all.  In fact....I would expect that under current conditions with more and more water vapor in the air.  To be fair...I haven't looked at the other "segments" of the Arctic and looked at EACH SEGMENTS snow history over the last 20 years (I assume you are saying that you DID something like that).

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I would argue that low-level cold air emanating from Greenland & AMOC shutdown is becoming sufficient to overwhelm the +GHG signal in certain regions (like Hudson Bay and Quebec, as well as northern Europe) which is why these are the only polar regions with any apparent cooling.


I would argue that you might be giving "short shrift" to the fact that the Arctic has been losing ice....and the albedo difference in the ocean is MASSIVE.  Much bigger than the HIGHER albedo of going from trees to grassland.  As well....the amount of energy to melt the ice...is now being used to warm the water, and that warming water can retain that heat way more than the atmosphere can retain cold (per your explanation of why Greenland's surface might cool).

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It should also be noted that despite significant melt occurring in April, there was no volume decrease on DMI. This goes to show that the absolute change year over year is, IMO, being overlooked.

One year....and especially one month....does not "hold much water" (pun intended:).  I don't dismiss it totally...but it IS only one month.

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Greenland losing mass as a whole is bad, but if precipitation on Greenland is increasing, then the total amount of yearly freshwater Greenland is unleashing on the NATL is going to be increasing much more than predicted,

Yes....if that happens (more precipitation on Greenland)....then I would expect more fresh water runoff.  Whether that is MORE than predicted.....that of course depends on the current prediction in the models.

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and ice gained while ice is lost does not take away the freshwater runoff into the NATL. Perhaps this is why the models are not account for how quickly these changes seem to be appearing?

OK...you lost me here:  "ice gained while ice is lost".  No idea what you mean there.

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If Hansen is right, then some areas see a 20 degree C decrease in annual temperatures in the span of 30 years. That is about as bad as nuclear winter. And it affects all of Europe and much of North America.

Keep in mind that western Greenland has WARMED significantly over the past 10 years.  If you're looking for the tipping point.....it certainly hasn't hit as yet.  You "seem" to be saying (my guess) that it WILL HIT when the Arctic is first ice free (maybe within 5 years).

The fact that Greenland IS MELTING....is certainly putting more cold fresh water into the northern Atlantic.  And that WILL effect the ocean currents of the northern Atlantic....AND...the weather/climate of northern Europe.

But I do NOT see anything in the next 10 years overriding the effects of:

1) Continued GHG emissions
2) Continued and GROWING positive feedback effects
3) Continued low albedo of the Greenland ice sheet itself
4) Continued and growing lower albedo of the Arctic ocean itself

In short....I don't see the "war" being won by cold fresh water melting from Greenland....over numerous other effects.


 
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TerryM

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Re: Hansens predictions for Future Ice
« Reply #24 on: May 05, 2016, 06:08:35 PM »
Gentlemen



Could I ask that you look at a map showing the province of Quebec, the province of Newfoundland and Labrador as well as the territory of Nunavik, Quebec, before continuing your argument?


It appears as though the region you are discussing might be described as Nunavik, Portions of eastern Nunavut, possibly with the addition of Labrador as well as portions of Northern Ontario & mahaps bits of Manitoba.


Postulating an ice sheet that would cover all of the province of Quebec seems outlandish, it gets hot in Montreal, but the retention of one or more of the small remnants of the Laurentide ice sheet still extant on Baffin Island, Nunavut, or possibly even small growth in one or more of them, might just fly.


Terry

crandles

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Re: Hansens predictions for Future Ice
« Reply #25 on: May 05, 2016, 06:13:02 PM »

But I do NOT see anything in the next 10 years overriding the effects of:
...

In short....I don't see the "war" being won by cold fresh water melting from Greenland....over numerous other effects.

Quite right. Hansen assumes cold fresh water injection doubles ~eight times over for a 256 fold increase. That isn't going to happen in next 10 years.

Seems rather doubtful Greenland will do that with a few deep narrow channels where ocean water can get at the ice. West Antarctica with hundreds of miles wide access for ocean to retrograde bed slopes that could well be subject to cliff failures offers more prospects for rapid increases. Even so, 256 fold increase is a lot.

bbr2314

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Re: Hansens predictions for Future Ice
« Reply #26 on: May 05, 2016, 06:38:00 PM »
Replies in bold!

Also re: 10 yr impact -- I think the map will resemble something like what 2070 or 2075 look like on the Hansen maps, if you were to imagine. We are clearly already seeing an impact verging on 2065.

Quote
Using caps lock repeatedly throughout your post would make you seem to be the Donald Trump here, no?

I use it for emphasis.....and my hands aren't small ;D

Quote
Of course it will be in balance when the energy coming in equals the energy coming out; the albedo effect is perhaps the single most important factor when it comes to this, and is why it could overwhelm the (admittedly enormous) +GHG signal that humans have created.

So let's take a STEP BACK to take a  40,000 foot view....and think about what the major issues of physics at play:

1)  GHG are still high...and going higher (perhaps MUCH higher depending on how the feedback effects like permafrost and others continue to play out)....and when we get out "s***" together on policy.  And don't forget....we still have a filthy China and India that will be cleaning up their air over time....and that will INCREASE temps due to diminished amount of aerosol, which will allow energy from the sun to work on that growing level of GHG.

Correct!

2)  We have more cool....fresh water being added to the ocean system from the current melting of Greenland ice sheet.  The effects of which are dependent on ocean currents (or the shut down of some of those currents as you note).

Correct

3)  We have more and more ice free ocean in the Arctic (currently).....at an earlier and earlier date with the passage of time over the next 10 - 20 years (until I see those change)

Correct


4)  We continue have a Greenland that has continued to LOSE albedo over the last decade....and that has NOT turned around as yet.  And unfortunately.....all that crappy looking coal dust and forest fire dust isn't going anywhere... much of it just keeps melting down and sitting on the top soaking up energy.  And there is STILL coal dust flying around for the foreseeable future (40 years AT LEAST) to provide an annual "topping"....not to mention increased forest fire "dust".

Correct!

Quote
Nick Naylor actually describes something that happened (rapidly cooling October) in several recent years in the US, most notably the sea ice minimums of 2011/12, which saw NYC's snowiest October on record and its earliest 4"+ storm on record (a few days into November in 2012).

I EXPECT snow storms in the northeast US to continue to be "nasty"....and BIGGER in coming 20 - 40 years.  More open ocean....more water vapor, etc.  A "snowiest October" on record IS what I would currently expect.  It's New York....not North Carolina.

The increase in snow (not just in October) began in Boston in the early 90s, in NYC in the mid-90s/early 2000s, in Philly in the mid 2000s, DC by 2010, and is now pushing into Richmond and Norfolk, which had previously seen declining averages before past few winters. Unless this apparent trend is some kind of illusion. But it is happening further and further S & W, almost like dominoes.
 
 
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While conditions that previously created the ice-sheets had much lower CO2 concentrations, Hansen's research would imply surface temperatures cold enough to allow ice-sheet regeneration in many regions. His research needs only be a little bit wrong for the cold to expand west into Quebec/Hudson Bay as well.

Keep in mind.....his research can be wrong on EITHER SIDE of his expectations (could be surface temperatures not nearly as cold, which I am much more inclined to think would happen).

Correct, but I think our current situation points to some decent likelihood of verifying his "bad" numbers.

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Why is it that Quebec is the only polar region with substantial and consistent +++ snowfall departures??

It (Quebec the province) is surrounded on basically 80% of its borders by ocean (or the ocean is VERY CLOSE).  That is NOT surprising to me at all.  In fact....I would expect that under current conditions with more and more water vapor in the air.  To be fair...I haven't looked at the other "segments" of the Arctic and looked at EACH SEGMENTS snow history over the last 20 years (I assume you are saying that you DID something like that).

Remember that Quebec may be surrounded on three sides by ocean but in a world with an ice-free Arctic, the polar trades reverse and it becomes (typically) downwind of Greenland; the perma-vortex in Foxe Basin/Baffin Bay is also responsible for this, dumping the low-level cold exiting Greenland into Hudson Bay and Quebec.

The two area that air entering Quebec normally originate from are freshwater and form very thick first year sea ice every year. In fact, Hudson Bay and parts of Uvgava Bay have thicker ice than most of the Arctic, per HYCOM.

Perhaps in the case of a warmer Greenland and an increasingly ice-free Arctic, cold air dumping off of Greenland not only enters Quebec more often, but "favors" the higher albedo of the non-soot-tarnished first year ice over these areas? At this point even two-year ice is going to begin accumulating significant amounts of crap.

Both Hudson/Baffin are closer to freshwater than the rest of the Arctic too, and with Greenland's melt flowing directly into both regions, they are insulated from solar increases unlike the Arctic Ocean.


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I would argue that low-level cold air emanating from Greenland & AMOC shutdown is becoming sufficient to overwhelm the +GHG signal in certain regions (like Hudson Bay and Quebec, as well as northern Europe) which is why these are the only polar regions with any apparent cooling.


I would argue that you might be giving "short shrift" to the fact that the Arctic has been losing ice....and the albedo difference in the ocean is MASSIVE.  Much bigger than the HIGHER albedo of going from trees to grassland.  As well....the amount of energy to melt the ice...is now being used to warm the water, and that warming water can retain that heat way more than the atmosphere can retain cold (per your explanation of why Greenland's surface might cool).

The annual added insolation to the northern prairies in the US/Russia/Canada is huge just because of normal dynamics/sun angle, no? These areas receive vastly more insolation than the Arctic on an annual basis, therefore smaller changes in albedo to locations farther removed from true North make a bigger impact on climate.

While losing the Arctic Ocean's sea ice in the summer is a very big deal, there are other ongoing effects at work as well, and if snow cover or sea ice begin to increase in the mid-latitudes -- especially in summer, when the sun is highest -- who is to say that the feedback could *not* counter a mostly-ice-free Arctic Ocean?

This argument may seem ridiculous today but if Hansen's map comes to fruition there is a decent chance sea ice would extend from Canada to the UK while, initially, large chunks of the Arctic Ocean will also remain prone to melting during summer. The maps seem to show the Arctic warming most by 2065 with a gradual cooling thereafter. Now what does that imply?


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It should also be noted that despite significant melt occurring in April, there was no volume decrease on DMI. This goes to show that the absolute change year over year is, IMO, being overlooked.

One year....and especially one month....does not "hold much water" (pun intended:).  I don't dismiss it totally...but it IS only one month.

It happens all the time, probably every spring, and if it is being overlooked it is a problem. Every drop counts!

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Greenland losing mass as a whole is bad, but if precipitation on Greenland is increasing, then the total amount of yearly freshwater Greenland is unleashing on the NATL is going to be increasing much more than predicted,

Yes....if that happens (more precipitation on Greenland)....then I would expect more fresh water runoff.  Whether that is MORE than predicted.....that of course depends on the current prediction in the models.

Quote
and ice gained while ice is lost does not take away the freshwater runoff into the NATL. Perhaps this is why the models are not account for how quickly these changes seem to be appearing?

OK...you lost me here:  "ice gained while ice is lost".  No idea what you mean there.

I meant that some days see the pack gain in the N and lose in the S (or vice versa, whatever). Even though the day's total may come to 0 on a graph, the actual loss could have been significant, and the localized effects of melting ice are not mitigated by falling snow in another location. This means that we may be underestimating the amount of discharge Greenland emits each year, and even this function *without* additional total ice loss shows impacts could be significant.

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If Hansen is right, then some areas see a 20 degree C decrease in annual temperatures in the span of 30 years. That is about as bad as nuclear winter. And it affects all of Europe and much of North America.

Keep in mind that western Greenland has WARMED significantly over the past 10 years.  If you're looking for the tipping point.....it certainly hasn't hit as yet.  You "seem" to be saying (my guess) that it WILL HIT when the Arctic is first ice free (maybe within 5 years).

I am saying that it might be the tipping point. It certainly seems possible based on what happened after 2012. What other explanation for the absurd uptick in 2013/14 is there? Remember that this does not happen year after year, rather it seems to occur in increasingly frequent/dramatic spurts punctuating a more gradual general increase in Greenland melt. These push the cumulative impact higher and higher.

The fact that Greenland IS MELTING....is certainly putting more cold fresh water into the northern Atlantic.  And that WILL effect the ocean currents of the northern Atlantic....AND...the weather/climate of northern Europe.

But I do NOT see anything in the next 10 years overriding the effects of:

1) Continued GHG emissions
2) Continued and GROWING positive feedback effects
3) Continued low albedo of the Greenland ice sheet itself
4) Continued and growing lower albedo of the Arctic ocean itself

In short....I don't see the "war" being won by cold fresh water melting from Greenland....over numerous other effects.

I wonder if surface warming of Greenland translates into surface cooling wherever that air ends up after it leaves Greenland. The warmer it gets the more likely it is the air, supercooled at night, ends up filtering through the increasingly prevalent cracks & pores within the ice sheet. With an average depth of 6KM the Greenland ice sheet is an incredible heat sink and far surpasses the capabilities of the Arctic Ocean, IMO. We have barely begun to truly "expend" its capabilities but that time is about to end and I think the results will be worse than anyone here can imagine.

marcel_g

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Re: Hansens predictions for Future Ice
« Reply #27 on: May 05, 2016, 06:48:35 PM »
Gentlemen



Could I ask that you look at a map showing the province of Quebec, the province of Newfoundland and Labrador as well as the territory of Nunavik, Quebec, before continuing your argument?


It appears as though the region you are discussing might be described as Nunavik, Portions of eastern Nunavut, possibly with the addition of Labrador as well as portions of Northern Ontario & mahaps bits of Manitoba.


Postulating an ice sheet that would cover all of the province of Quebec seems outlandish, it gets hot in Montreal, but the retention of one or more of the small remnants of the Laurentide ice sheet still extant on Baffin Island, Nunavut, or possibly even small growth in one or more of them, might just fly.


Terry

Terry, I believe some one here posted some recent photos of small ice sheets in the Baffin or Ellesmere area that had shrunk significantly over the last few decades. So even if this cold pool does temporarily cool the climate in the areas west of Greenland, any ice sheets that survive would be starting from a significant deficit. My own guess is that greatly reduced arctic sea ice will warm pretty much everywhere except the cold pool, bringing more melting and lowered albedo to higher and higher elevations on GIS. Maybe northern Quebec and Europe will get larger amounts of snow due to increased temp differential between the cold pool and the rest of the ocean, and a longer snow season, but I'd be surprised if that snow lasted into summer.

anotheramethyst

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Re: Hansens predictions for Future Ice
« Reply #28 on: May 06, 2016, 05:41:32 AM »
The evidence of crocodiles and tropical vegetation in the polar regions in the archaeological record solidly refute any natural earth-based mechanism that would reverse a not climate and turn it into an ice age.  Earth can get a lot hotter than it is now, given the right (or in our case, very very wrong) conditions.  The normal cyclic variability if climate on Earth is explained by variations in Earth's position in the sun and by CO2 concentrations.  There may be small local cooling effects at various points in this transition, but none will reverse the global temperature trend.  They will be indications if increased variability and increased volatility.  The gardeners and farmers on this site will tell you that the predictability of climate is what makes agriculture possible, and increasing volatility in the weather will lead to more famine than the rise in temperature alone. 

We all want there to be some sort of climate band-aid that planet Earth will call upon to save us all, but that's not going to happen, it's not how physics works.  We humans have turned up the planetary thermostat by 130ppm CO2 and the heat will continue to rise until it finds its own balance based on thermodynamics.  I know that movie "The Day After Tomorrow" spread a lot of misconceptioms about thermohaline circulation and ice ages.  It was based on old science from a Eurocentric world view.  When the ocean conveyor belt shuts down it just means some parts of Europe and North America will heat up a little less quickly than the rest of the planet, but that doesn't help us much because all the agriculture that humans have devrloped for 10,000 years are based on a climate that will no longer exist at that point. 

crandles

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Re: Hansens predictions for Future Ice
« Reply #29 on: May 06, 2016, 12:17:20 PM »
When the ocean conveyor belt shuts down it just means some parts of Europe and North America will heat up a little less quickly than the rest of the planet, but that doesn't help us much because all the agriculture that humans have devrloped for 10,000 years are based on a climate that will no longer exist at that point.

My understanding was that a shut down would cause cooling. Models don't shut down the meridional overturning circulation except for one model and that only did so when forced with a ridiculously too large fresh water injection. Models do show a slow down and this doesn't cause a cooling but just a reduction in the rate of warming.

There have been shut down in the past but circumstances were different. IPCC Fifth Assessment reported that it is very unlikely that the AMOC will undergo a rapid transition (high confidence).

https://en.wikipedia.org/wiki/Shutdown_of_thermohaline_circulation

ktonine

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Re: Hansens predictions for Future Ice
« Reply #30 on: May 06, 2016, 01:51:10 PM »
Models do show a slow down and this doesn't cause a cooling but just a reduction in the rate of warming.

Is this is a bug or a feature?  We know how poorly models do with sea ice projections. And models do not show the observed 'warming hole' in the North Atlantic.  Models also have excessive ocean mixing, meaning little or no stratification.  Models do not form Antarctic Bottom Water at the proper locations. From Hansen et al:

Quote
The ocean model must be able to simulate realistically the ocean’s overturning circulation and its response to forcings including freshwater additions. Heuze et al. (2013, 2015) point out that simulated deep convection in the Southern Ocean is unrealistic in most models, with AABW formation occurring in the open ocean where it rarely occurs in nature. Our present ocean model contains significant improvements (see Sect. 3.2) compared to the GISS E2-R model that Heuze et al. include in their comparisons. T

And of course there is the reliability of ice sheet models.  The main point comes down to linear or non-linear ice sheet disintegration. Hansen et al:

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The fundamental question we raise is whether ice sheet melt in response to rapid global warming will be nonlinear and better characterized by a doubling time for its rate of change or whether more linear processes dominate. Hansen (2005, 2007) argued on heuristic grounds that ice sheet disintegration is likely to be nonlinear if climate forcings continue to grow, and that sea level rise of several meters is possible on a timescale of the order of a century. Given current ice sheet melt rates, a 20-year doubling rate produces multi-meter sea level rise in a century, while 10- and 40-year doubling times require about 50 and 200 years, respectively

oren

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Re: Hansens predictions for Future Ice
« Reply #31 on: May 06, 2016, 02:14:13 PM »
Can someone with more weather acumen relate to the question of whether such a very cold and very large pool in the north Atlantic would cause massive storms because of the big difference between a very warm mid-Atlantic to the very cold north? And those storms might cause more mixing and reduce the stratification, acting as a negative feedback to the cold pool. I'm asking based on intuition, with zero knowledge on such a subject.

bbr2314

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Re: Hansens predictions for Future Ice
« Reply #32 on: May 06, 2016, 09:02:36 PM »
Can someone with more weather acumen relate to the question of whether such a very cold and very large pool in the north Atlantic would cause massive storms because of the big difference between a very warm mid-Atlantic to the very cold north? And those storms might cause more mixing and reduce the stratification, acting as a negative feedback to the cold pool. I'm asking based on intuition, with zero knowledge on such a subject.
I would think that the cold pool has to get cold enough to form sea ice over a majority of its area before that would happen -- as the sea ice plunges southwards, the gradient between it & the Gulf Stream would increase to the point where the GS is punching almost directly into sea ice (as happens off Newfoundland/Nova Scotia some yrs -- this would just be on a much bigger scale).

Also, notice the 12z EURO today encouraging perma-winter over Quebec and Hudson bay. I wonder if the record-early anomalies over Beaufort encouraging ++ridging there, which also keeps the trof/Baffin Bay vortex anchored in almost the same spot?



One more thing: it appears that NCEP is initializing snowcover over Canada incorrectly. Climate Reanalyzer shows almost no depth over most of Quebec whereas the Canadians have major pack over the entire province. I would think this is cause for major inaccuracies in the American models?




bbr2314

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Re: Hansens predictions for Future Ice
« Reply #33 on: May 07, 2016, 08:59:00 AM »
Couldn't really ask for a better illustration of how icepack growth *could* be possible in QC/HB. These anomalies have been pervasive but the upcoming setup is just absurd -- heat backs up the Rockies and off the ATL into Greenland while the Baffin Bay vortex is sheltered by what remains of the cryosphere (and it makes the most of it, too).


P-maker

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Re: Hansens predictions for Future Ice
« Reply #34 on: May 07, 2016, 10:08:55 AM »
Just as the ”Cold Blob” off New Foundland is ascribed to excess melting of Arctic sea ice and Greenland glaciers in most recent years, it is tempting to ascribe the “Warm Blob” in the NE Pacific to a similar lack of cold fresh water there.

Over the past few decades, the Pacific NW has seen a steady decline of streamflow into the Pacific Ocean, most notably:

1)   Lower spring peak flow, which appears 1-3 weeks earlier now due to higher winter temperatures
2)   Higher rates of sublimation of the snow pack, reducing overall runoff during the spring season
3)   Smaller glaciers in the Rockies, reducing overall ablation and runoff during the summer
4)   Higher evaporation from river basins, leading to lower runoff
5)   Reduced pumping rates from ancient aquifers, leading to less water in the rivers
6)   Higher salinities in those rivers, which – unlike the Colorado River – actually reaches the ocean

Just by looking at the map posted by BBR, it is quite obvious that these two blobs may be connected, since they both have manifested themselves at the same time in history, when our GHG pollution sh.. has started to hit the fan seriously.

To my eyes, the Warm Blob is setting up the warm ridge over NW North America and the Cold Blob is pushing the cold trough down over the NE. Hope you guys have got your sun screens and mittens ready in the right places.

Cheers P
« Last Edit: May 07, 2016, 10:19:00 AM by P-maker »

johnm33

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Re: Hansens predictions for Future Ice
« Reply #35 on: May 07, 2016, 02:25:03 PM »
I haven't read the Hanson paper but will, I do share some of the ideas he has as expressed here though.
When the ice cover is gone from the Arctic i think the freshwater inputs of Siberian rivers and those of Alaska and Canada will flow east and pass through the CAA. So the flow through Fury and Hekla becomes ever fresher, whatever water passes into Baffin bay will, as now, hug the coast of Baffin island joined by Greenland meltwater. As those waters move south they will be drawn into Hudson bay by tidal forces, thus Hudson freezes easier and harder on average than now with the distinct possibility of an extreme event leading to ice cover persisting long into the summer.
With no ice and no fresh water cover the warm surface of the Arctic ocean gives up a prodigious amount of moisture into the arctic sky. This has to condense and fall as rain or snow somewhere, anywhere south where the ground rises. The three main areas that i think will be most affected are the north slopes of the Pyranees/ Alps/Carpathians, around lake Baikal and down into the Himalayas, and from Alaska across to Ontario and points south. The warmer the ocean the greater the rate of evaporation, which means more snow, more snow means it'll persist longer into summer, and given enough snow i think any combination of these three could support summer ice/snow cover and become cold poles where they're sufficiently continental. Most of all i think this is a likely scenario because it allows the oceans to vent heat into the atmosphere sufficient to become a stable climatic regime, will we see this? I don't think so but some of us may see signs of it. It looks to me that we've entered the transition with probably centuries of climate chaos ahead. Europe and north America look to be in the crosshairs, Europe because the cool pool looks set to persist and expand delivering maybe as much as -10c cooling on the average day, and America because of the extreme difference between the Gulf of Mexico and south west Hudson

AmbiValent

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Re: Hansens predictions for Future Ice
« Reply #36 on: May 07, 2016, 03:02:42 PM »
I don't think that could work. Even assuming a warm Arctic Ocean produces extra moisture, this wouldn't fall as snow in mountain areas that far away. It's far more likely that it falls as rain somewhere in between, unless it runs into a very cold area that's rather nearby. And for the area to be cold while the Arctic Ocean is warm, it would have to be quite high. So I think if there were areas where the moisture would fall as snow, those would be the mountains of Greenland and Scandinavia. And I doubt that more snow there would be enough to start a regional cooling trend.
Bright ice, how can you crack and fail? How can the ice that seemed so mighty suddenly seem so frail?

Tor Bejnar

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Re: Hansens predictions for Future Ice
« Reply #37 on: May 07, 2016, 04:30:01 PM »
I would be surprised not to see some areas with growing ice sheets or glaciers.  Even today there are a few glaciers around the world that are 'growing' because of increased local snowfall. 

I've stood on glaciers wearing shorts because it was warm (above my ankles, anyway).  One of these N.Z. glaciers was advancing at the time (or was a few years later).  What matters is the mass balance between (mostly winter) snowfall and annual melt.  I recall seeing a glacier that was in retreat, but that just a decade or so earlier had been advancing through (low elevation) semi-tropical vegetation, and seeing ice a few meters away from palms was awesome.  Obviously that glacier was melting year-round around its snout.

So, if arctic evaporation increases, increased snowfall in some places is a sure thing.  How extensive this will be and where, however, I have basically no clue.
Arctic ice is healthy for children and other living things.

bbr2314

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Re: Hansens predictions for Future Ice
« Reply #38 on: May 08, 2016, 07:18:20 AM »
I don't think that could work. Even assuming a warm Arctic Ocean produces extra moisture, this wouldn't fall as snow in mountain areas that far away. It's far more likely that it falls as rain somewhere in between, unless it runs into a very cold area that's rather nearby. And for the area to be cold while the Arctic Ocean is warm, it would have to be quite high. So I think if there were areas where the moisture would fall as snow, those would be the mountains of Greenland and Scandinavia. And I doubt that more snow there would be enough to start a regional cooling trend.
It depends on the season. A warm Arctic will be more likely to induce rain vs snow in summertime, of course. But in the transition seasons, the feedbacks are different. As the land cools rapidly, the ocean retains heat, sparking major snowstorms along the coast and well inland -- especially with access to the Greenland cold reservoir, etc.

As more of the Arctic opens in the summer the transition months back to winter are actually seeing anomalously high northern hemisphere snowcover. Perhaps there is a flipping point in the distant (or not so distant) future where this accelerates even more significantly -- maybe Blue Arctic is that point?

I am very nervous that Sandy was a symptom of 2012's abysmal sea ice and that we are in for a repeat or worse (or several) this year. Important to note, storms like Sandy actually drop large amounts of snow -- or at least, they can -- even in fall months like October.

kiwichick16

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Re: Hansens predictions for Future Ice
« Reply #39 on: May 08, 2016, 08:53:49 AM »
@ tor

the glaciers in nz are all retreating

bbr2314

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Re: Hansens predictions for Future Ice
« Reply #40 on: May 16, 2016, 02:25:21 AM »
It looks like salinity is now dropping precipitously year over year in the NATL. Note the deep greens already appearing SE of Greenland. The 3-yr change is -10% or more in spots!

I think this is to blame for the snow flurries currently flying across the Northeast (and previously Europe) as well as the major + snow anomalies that continue to endure across Quebec. It's almost June!


johnm33

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Re: Hansens predictions for Future Ice
« Reply #41 on: May 16, 2016, 02:50:26 PM »
I've been wondering if that less saline cool water is actually gaining heat as it crosses to Europe, and the Arctic, instead of shedding it through evaporation. With Beaufort smashed there's nothing stopping the river discharges from the north shores of N.America passing straight through the CAA, is there time for the Siberian river water to get there before sept?

LRC1962

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Re: Hansens predictions for Future Ice
« Reply #42 on: May 16, 2016, 10:13:47 PM »
A few points to ponder IMO.
As the Arctic loses ice there will be far more wave action and big changes in how the Currents move around the Arctic. These will IMO result in a greater mixing of water, therefore reducing the long-term impact of freshwater entry.
IMO I believe the flow of water will drop greatly in the near future because that flow depends upon melt glaciers which are melting very fast and once gone will no longer feed those rivers.
As far as more moisture, leading to more snowfall, leading to larger glaciers? That only will work if moisture-laden systems dump their loads as snow in the proper places. With a weakening jet stream meandering around the NH, I would not bank on systems dumping their moisture anywhere near those glaciers.
Edit:
As TerryM has stated, Candian provinces and territories are very large. They also tend to run North-south. This means that what happens in the northern part of a province never has anything close to what is going on in the southern part. On top of that, depending upon which province you are in, you can get systems hitting it from as many as 4 different directions. An example: In New Brunswick's east side on a 50 km stretch of road, it is not uncommon to go from snow to freezing rain to rain back into snow.
« Last Edit: May 16, 2016, 10:26:30 PM by LRC1962 »
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bbr2314

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Re: Hansens predictions for Future Ice
« Reply #43 on: July 04, 2016, 03:42:25 AM »
I don't want to put too much faith in this tool but it is now showing a decent chance of at least some ice in Hudson/Baffin Bay (and a lot in Foxe Basin) surviving through late August. If it lives that long, the possibility of it becoming the first multi-yr ice in Hudson bay in (what I would assume to be) a very long time becomes real... and juxtaposes pretty crazily against the horror story elsewhere in the Arctic.



If DMI is correct, the thickest area of remaining ice (or one of the thickest) is Foxe Basin!


magnamentis

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Re: Hansens predictions for Future Ice
« Reply #44 on: July 04, 2016, 01:13:07 PM »
.... chance of at least some ice in Hudson ....... surviving through late August. If it lives that long, the possibility of it becoming the first multi-yr ice in Hudson bay in

this won't happen, i'd bet a lot on a NO to ice surviving that far south in hudson, bold but simply no :-)

Quote
If DMI is correct,

DMI ice thickness chart is way off since i'm following it. often shows 5m ice where is open water.
last example is that where it shows now the +4m ice north of the CAA, a few weeks ago there was a large and several hundred kilometers long lead that only closed by drift, not by refreeze. i think the DMI falls for piled up ice too much which does not represent the real, grown and consistent thickness. last year most of the 4-5m ice (according to DMI chart) went "poof" in beaufort which i simply don't believe, i think that the ice was not 5m thick there and even though the years 13 and 14 were building new multiyear ice i don't believe that that was building several meters in thickness over that period which was not a hot one but by no means that cold.

bbr2314

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Re: Hansens predictions for Future Ice
« Reply #45 on: July 04, 2016, 08:52:49 PM »
.... chance of at least some ice in Hudson ....... surviving through late August. If it lives that long, the possibility of it becoming the first multi-yr ice in Hudson bay in

this won't happen, i'd bet a lot on a NO to ice surviving that far south in hudson, bold but simply no :-)

Quote
If DMI is correct,

DMI ice thickness chart is way off since i'm following it. often shows 5m ice where is open water.
last example is that where it shows now the +4m ice north of the CAA, a few weeks ago there was a large and several hundred kilometers long lead that only closed by drift, not by refreeze. i think the DMI falls for piled up ice too much which does not represent the real, grown and consistent thickness. last year most of the 4-5m ice (according to DMI chart) went "poof" in beaufort which i simply don't believe, i think that the ice was not 5m thick there and even though the years 13 and 14 were building new multiyear ice i don't believe that that was building several meters in thickness over that period which was not a hot one but by no means that cold.

Agree with you on both points. DMI seems inaccurate, and it is very unlikely HB ice survives. BUT, I will say that pretty much all models show some ice that is 3M+ thickness in HB (likely what Slater's map shows persisting), so it certainly has some durability... may make it to September at the very least.

magnamentis

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Re: Hansens predictions for Future Ice
« Reply #46 on: July 04, 2016, 09:13:40 PM »

just for fun, if you like i'd bet on that won't happen. where the ice in HB is located mostly depends on the prevailing winds over a certain period and during a certain state. the spot where that 3m thick ice is now,
was second to be ice free last year. so that ice was driven there an eventually piled up by winds. i'm not a pro but considering winter temps and early temps hovering around zero in that spot, how could 3m ice have grown there during the short time it was cold enough? i say it's drift ice that will fall apart soon when the surrounding ice
will be gone and some nice summer weathers (storms) from different directions will shake it loose.

bot no problem, i can't tell for sure and i might be wrong on this, just a little detail for the fun part, that's how i see it :-) else i see things very similar like you, stick to the bigger picture and marvel at the details that unfold with at times with open mouth :-)

the death of the ice is like any death, only thing we know is that it's gonna happen but nobody know exactly when, just probabilities get higher :-)

enjoy further

bbr2314

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Re: Hansens predictions for Future Ice
« Reply #47 on: July 04, 2016, 09:28:12 PM »

just for fun, if you like i'd bet on that won't happen. where the ice in HB is located mostly depends on the prevailing winds over a certain period and during a certain state. the spot where that 3m thick ice is now,
was second to be ice free last year. so that ice was driven there an eventually piled up by winds. i'm not a pro but considering winter temps and early temps hovering around zero in that spot, how could 3m ice have grown there during the short time it was cold enough? i say it's drift ice that will fall apart soon when the surrounding ice
will be gone and some nice summer weathers (storms) from different directions will shake it loose.

bot no problem, i can't tell for sure and i might be wrong on this, just a little detail for the fun part, that's how i see it :-) else i see things very similar like you, stick to the bigger picture and marvel at the details that unfold with at times with open mouth :-)

the death of the ice is like any death, only thing we know is that it's gonna happen but nobody know exactly when, just probabilities get higher :-)

enjoy further

Would not like to bet, you are most likely correct, but I think the main implications of HB retaining more ice later into summer = easier refreeze in the fall, as wherever the ice remains, SSTs are unlikely to get much above -1.8C.

Also, it would encourage residual cold LPs (contrast with very warm North America), forcing additional heat *over* Hudson Bay and into the CAA, as the models are now showing for an extended period.