"Smart" and "Stupid" Questions - Feel Free To Ask

[binntho]

Wait, is the question about the dissolution of methane gas or solid methane hydrates? Hydrate dissociation is an endothermic process.

Dunno. Just saw that it was about the ESS and I thought, "methane gas from the sea floor dissolving in the water column." But are there any solid methane hydrates (= clathrates?) in that area?

[nanning]

Newly published study indicates we need more ocean measurement tools.  My stupid question is, Where is the money to make this a reality?

[sarc]
Everywhere and nowhere.
Money is not real, you can create it as a bank or government. It is called Quantitative Easing. If it can prop up rich people's casino systems, why not scientific research?

[/sarc]

[binntho]

Newly published study indicates we need more ocean measurement tools.  My stupid question is, Where is the money to make this a reality?

Everywhere and nowhere.
Money is not real, you can create it as a bank or government. It is called Quantitative Easing. If it can prop up rich people's casino systems, why not scientific research?

Hear hear! Let's imagine some more money (just joking - it takes a government to do that, but then the fat cats are in trouble, the money just keeps flowing ...)

[LeftyLarry]

<snip>
I don't understand how e.g. elephants evolved with the growing technology of human hunters. Aren't they also vulnerable to being killed with spears and traps, just like other megafauna up north?
To me it looks like Africans had a different mentality. Perhaps because they stayed close to their roots?

Pleistocene African humans didn't need warm watertight clothes so they didn't have the perverse incentive to kill for non-nourishment. I call it perverse because no real predator behaves this way

Many predators kill for non-nourishment.
Male Lions will kill the cubs so they can mate with the lioness, it puts her back in heat.
Bears and other predators do the same.
Chimps have been proven to actually Murder within their own species over habitat, sex, jealousy, whatever.

[Neven]

The stupid questions and discussions here preferably have something to do with (Arctic sea) ice.

[Shared Humanity]

The stupid questions and discussions here preferably have something to do with (Arctic sea) ice.

We need an irrelevant question thread.

[uniquorn]

Wait, is the question about the dissolution of methane gas or solid methane hydrates? Hydrate dissociation is an endothermic process.

Dunno. Just saw that it was about the ESS and I thought, "methane gas from the sea floor dissolving in the water column." But are there any solid methane hydrates (= clathrates?) in that area?

Good pointers. I am wondering about possible additional cooling as well as the cold shallow sea floor.

[Aleph_Null]

I was startled to hear Sam Champion on ABC kvetching about the disagreement between EURO and GFS this evening, by way of explaining why we don't have a better idea where Dorian is headed. "Well of course," I'm thinking, "Champion has to use the same stuff those folks in the ASIF melting-season thread have been struggling with." That should give you an idea how stupid I am, thus qualifying my stupid question!

I know some folks might say "Yep, the models are crap anymore." I was hoping to find something like a plotted year-over-year trend of forecasting skill -- but I don't know how or if such a thing could be quantified. Thanks.

[Tom_Mazanec]

I was startled to hear Sam Champion on ABC kvetching about the disagreement between EURO and GFS this evening, by way of explaining why we don't have a better idea where Dorian is headed. "Well of course," I'm thinking, "Champion has to use the same stuff those folks in the ASIF melting-season thread have been struggling with." That should give you an idea how stupid I am, thus qualifying my stupid question!

I know some folks might say "Yep, the models are crap anymore." I was hoping to find something like a plotted year-over-year trend of forecasting skill -- but I don't know how or if such a thing could be quantified. Thanks.

Thanks to the butterfly effect, we will probably never get much better than we are now. The tiniest error grows and multiplies fast.

[Feeltheburn]

My stupid question is whether the heat transfer effects of dynamic water evaporation and precipitation are measured, or even measurable. We know that water's net effect on climate is whether its power as a green house gas is less than, equal to, or greater than its albedo effect when in the form of clouds. I don't think this has been resolved, and is why the effect of water forcing in connection with other green house gases is a point of debate.

Does the debate also consider the evaporative cooling effect of water? the latest heat of vaporization of water is 540 cal/gram, which is 5-1/2 times more heat energy than it takes to heat 1 gram of water from 0 to 100 degrees C. If the mass of water vapor emitted by the oceans and other bodies of water could be determined, we could then calculate the quantity of heat that is carried from the earth's surface to the upper atmosphere (20,000 - 40,000 feet up) by evaporating water.

And this process is by no means a zero sum game where this heat energy falls back to earth in precipitation. Rather just the opposite. The very process of condensation means that all the latent heat of vaporization and also fusion held by the water vapor is expelled into the surrounding air. This rarified air is very cold and thin and cannot hold much water, hence precipitation. But it quickly absorbs the heat energy given up by the condensing water by its shear enormity. Because entropy dictates that heat moves from the direction of warmer air toward colder air, and because the colder air is even further up in the atmosphere, the heat is emitted back into space.

In short, my question is whether anyone has calculated and accounted for this heat energy movement from ocean to space, rather than just the effect of water vapor as either a glass ceiling that hold in heat or an umbrella that reflect the sun's energy back to space by albedo. I can't find any articles on it and don't really know its magnitude. Perhaps it's insignificant. However, I doubt that given the tremendous force of hurricanes caused by disturbances caused by extreme weather, which at its core, it extreme thermal gradients caused by rapidly evaporating and precipitating water and their attendant low pressure.

[Aleph_Null]

The tiniest error grows and multiplies fast.

From experience, there doesn't seem to be much question whether there are more tiny errors lately. But, you know, that's anecdotal. I wonder if anyone keeps data tracking the frequency of such tiny errors. My point: A practically obvious consequence of climate destabilization might be watching models break down in time with the icecap. But I'm looking for the study, if there is one.

[oren]

I think weather models could much better in the Arctic if there were more consistent buoy and weather station measurements in a widespread fashion. It would probably improve the global models as well.

[dnem]

I just finished The Weather Machine by Andrew Blum.  In the opinion of the well-regarded author, the models, and in particular the Euro, have improved markedly over the years, and continue to improve.  With ever better collection of existing conditions and increasing computational power, he expects improvements to continue.

“[A] vivid account of the history and evolution of the modern daily forecast . . . [Blum] is a sharp analyst and engaging guide, adept at translating difficult concepts in meteorology and computer science for the uninitiated.” (The Economist)

[nanning]

I just finished The Weather Machine by Andrew Blum.  In the opinion of the well-regarded author, the models, and in particular the Euro, have improved markedly over the years, and continue to improve.  With ever better collection of existing conditions and increasing computational power, he expects improvements to continue.

“[A] vivid account of the history and evolution of the modern daily forecast . . . [Blum] is a sharp analyst and engaging guide, adept at translating difficult concepts in meteorology and computer science for the uninitiated.” (The Economist)

Thanks for that info dnem .

From me:
The observation of: The models not really grasping the acceleration of changing climate; surprises and effects happening a lot earlier than expected, make me think that most professional people have lost sight/understanding of reality. Models are important tools for information about what's happening.

But, don't 'we' know enough already? 'We''re not acting! That's far more important.

P.S. 'we'='We'=consumerists

[dnem]

I very much agree with you Nanning, with respect to climate models.  The book is purely about weather forecasting, the useful prediction of the weather in a place, hours to days in advance.  The skill of weather prediction has been steadily improving as we collect denser and more accurate three dimensional data about the current state of the atmosphere (temperature, pressure, water content, etc.) and use those data to model the atmosphere forward hours to days into the future.

I have close to zero faith in the ability of climate models to predict the climate years to decades into the future.

https://cup.columbia.edu/book/useless-arithmetic/9780231132121

Useless Arithmetic: Why Environmental Scientists Can't Predict the Future

Orrin H. Pilkey and Linda Pilkey-Jarvis

Columbia University Press

Noted coastal geologist Orrin Pilkey and environmental scientist Linda Pilkey-Jarvis show that the quantitative mathematical models policy makers and government administrators use to form environmental policies are seriously flawed. Based on unrealistic and sometimes false assumptions, these models often yield answers that support unwise policies.

[nanning]

Thanks dnem  .
And you're right of course, sorry, I lost sight of the context there 

[Aleph_Null]

Thanks so much for your insights on forecasting -- especially for the book reference. From my obviamateur perspective, it looks like an arms race: gains in computing power versus more to compute, such as why the jet stream takes a short-cut over the Pole, or whether the tropopause is more lively.

[NotaDenier]

Sulfur dioxide reduces the amount of solar radiation reaching the earths surface?

If humans reduce their sulfur dioxide emissions from reduced coal burning and the burning of low sulfur diesel and bunker oil for ships, this should allow more solar insolation to reach the earths surface?

However will the cleaner air be offset arctic fires?

Dos soot from fires the cause the same affect as SO2?

Hope this make sense. I do think SO2 emissions will be going down slowly.

[karl dubhe2]

Sulfur dioxide reduces the amount of solar radiation reaching the earths surface? 

Yes, but it also caused acid rain.  Which freaked out people who made gravestones, and those who liked to fish.   SO2 concentrations have been dropping since the 1980s, IIRC.  The SO2 caused some of the sun's light to reflect off of the atmosphere into space, which caused "global cooling" and offset the warming effect from the CO2.   

They're sorta like mirror images, the opposite rather than the same thing.

I'll delete this if I'm very wrong.   

[crandles]

Sulfur dioxide reduces the amount of solar radiation reaching the earths surface?

If humans reduce their sulfur dioxide emissions from reduced coal burning and the burning of low sulfur diesel and bunker oil for ships, this should allow more solar insolation to reach the earths surface?

However will the cleaner air be offset arctic fires?

Dos soot from fires the cause the same affect as SO2?

Hope this make sense. I do think SO2 emissions will be going down slowly.

soot vs SO2

https://en.wikipedia.org/wiki/Sulfate Sulfate scatters light cooling climate but also has indirect effects on clouds which also cool climate.

https://en.wikipedia.org/wiki/Black_carbon Soot or black carbon warms the climate through albedo effects particularly when it lands on snow or ice. While it also absorbs radiation in atmosphere, it only spends an average of several days in the atmosphere so that is short term effect.

>SO2 emissions will be going down slowly
Volcanoes are far larger sources of SO2 than anthropogenic sources. So big eruptions send levels soaring (if you'll forgive the pun). Perhaps also location dependant declining in developed world while perhaps increasing in developing economies.

HTH

[binntho]

Sulfur dioxide reduces the amount of solar radiation reaching the earths surface?

If humans reduce their sulfur dioxide emissions from reduced coal burning and the burning of low sulfur diesel and bunker oil for ships, this should allow more solar insolation to reach the earths surface?

It does and sulfur emissions were a major problem when I was growing up. The acid rain destroying the forests of Europe was daily news (and a much bigger story than the current burning of the Amazonas), and summer days were never properly sunny because of the misty haze caused by SO2.

So a major clean-up operation of fossil fuels got rid of a hell of a lot of SO2 from the atmosphere. Some people postulated that the warming hiatus from the end of WWII and into the 70's was due to this massive SO2 pollution.

[NotaDenier]

SO2 emissions have gone down very little per this chart.

SO2 levels in the US have gone down a lot. I have not found a chart show global levels.

I did find a NASA page showing SO2 hot spots.

https://so2.gsfc.nasa.gov/

Sulfur dioxide reduces the amount of solar radiation reaching the earths surface?

If humans reduce their sulfur dioxide emissions from reduced coal burning and the burning of low sulfur diesel and bunker oil for ships, this should allow more solar insolation to reach the earths surface?

It does and sulfur emissions were a major problem when I was growing up. The acid rain destroying the forests of Europe was daily news (and a much bigger story than the current burning of the Amazonas), and summer days were never properly sunny because of the misty haze caused by SO2.

So a major clean-up operation of fossil fuels got rid of a hell of a lot of SO2 from the atmosphere. Some people postulated that the warming hiatus from the end of WWII and into the 70's was due to this massive SO2 pollution.

[binntho]

SO2 emissions have gone down very little per this chart.

SO2 levels in the US have gone down a lot. I have not found a chart show global levels.

Yes, it was the US and Europe that tacked SO2 pollution. But then the rapid economic growth of the Asian Tigers, and then China itself, filled in the gap.

So global SO2 has been static, European and American falling while East- and South Asian rising. But those areas with big SO2 pollution today are working on reducing their level of pollution as well.


From https://tamino.wordpress.com/2019/08/20/global-warming-how-fast/

If you compare this graph showing global warning since 1880 with the other showing global SO2 since 1850, it is striking how the pause (and slight fall) in global temperatures matches quite well the period of massively rising SO2 pollution. I doubt whether there is a well-established causal connection here, but on the other hand, while SO2 is rising faster than CO2, the former might well swamp the signal of the latter, which then manages to overtake as the rise of SO2 stalls.

[binntho]

Here's an extremely crude comparison between the two.

[binntho]

You are  right, it's not easy to find information on global SO2 concentration, but perhaps that is logical - SO2 pollution is local and does not travel far, and it washes quite quickly out of the atmosphere.

[NotaDenier]

Thanks for the answers. So even though SO2 is local and washes out quickly, the Asian countries produce so much continuously it effects the local climate to some degree. When coal use (and better pollution controls are installed) eventually decline, we may see a small bump in the temperature upwards?

[oren]

Yes. Small or not so small - we hope to find out when coal finally dies.

[Tom_Mazanec]

Was there, or was there not, a BOE in the mid-Holocene?

[binntho]

Was there, or was there not, a BOE in the mid-Holocene?

I guess you mean at the Holocene maximum?

A quick Google search gives this:

We show that the increased insolation during EHIM has the potential to push the Arctic Ocean sea ice cover into a regime dominated by seasonal ice, i.e. ice free summers. The strong sea ice thickness response is caused by the positive sea ice albedo feedback. Studies of the GRIP ice cores and high latitude North Atlantic sediment cores show that the Bølling–Allerød period (c. 12,700–14,700 years BP) was a climatically unstable period in the northern high latitudes and we speculate that this instability may be linked to dual stability modes of the Arctic sea ice cover characterized by e.g. transitions between periods with and without perennial sea ice cover.

Which seems to answer yes, and to imply that it's easy to get a seasonally ice free Arctic, and that it will lead to a climactically unstable period.

Most of the papers that pop up seem to agree that the Arctic was seasonally ice free during the Holocene Maximum, so I guess the answer to your question should be:

Yes, at least several hundreds of them!

[Tom_Mazanec]

But if I understand you, the problem was that we kept switching between BOE and ice covered. A permanent BOE would be stable, wouldn't it? And maybe not that bad if civilization could get started with several hundred BOEs.

[binntho]

But if I understand you, the problem was that we kept switching between BOE and ice covered. A permanent BOE would be stable, wouldn't it? And maybe not that bad if civilization could get started with several hundred BOEs.

Ah, BOE = "Blue Ocean Event", i.e. the "event" of all the ice melting out (or below a certain threshold) for at least long enough for it to be measured. In a seasonally free Arctic this would happen every year.

[Archimid]

Was there, or was there not, a BOE in the mid-Holocene?

Wonderfully stupid question.

No, there was not a BOE, even if the Arctic could have been ice free during summers.

When you talk about Mid Holocene you are talking about time frames of thousands of years.  A BOE is an unnatural event forced over years and decades, not millennia. 

I have seen papers that use shells that concluded that at no point during the Holocene the Arctic was ice free during summer.  But I find that a bit unbelievable as it doesn't make sense to the model of the climate that lives in my head.    I believe the following happened.

At some point during orbital maximum the arctic went mostly ice free, or maybe even ice free. The transition happened over centuries not years, with albedo increasing over centuries not decades. Luckily during all that time we had gigantic structures of ice in the continents that melted over millennia, not decades absorbing all the extra heat from the almost ice less Arctic.

Today all that remains is Greenland and permafrost and the ice is melting over years and decades, not centuries.  A BOE will happen suddenly and the extra heat won't be absorbed.

[binntho]

A BOE is an unnatural event forced over years and decades, not millennia. 

Is it? So the BOE stands for "unnatural event forced over years and decades". I thought it just meant "Blue Ocean Event", i.e. the event of the Arctic ocean being practically ice free.

This, i.e. was there ever an ice-free Arctic Ocean during the Holocen Maximum was I belive what the question was about, and deriding it as "wonderfully stupid" is just stupid.

The weight of evidence seems to be that the Arctic was seasonally ice-free during the maximum, so the answer to the question is YES.

[Archimid]

Really, is that the weight of the evidence? Show it. Be careful tho, the first links google throws at me are WUWT.


In the mean time, evidence for ice cover throughout the Holocene:

1. Like Today. N84 was ice covered all through the holocene.

https://epic.awi.de/id/eprint/42998/

2.  Unlike 20 years ago and like today, the peripheral seas during Holocene Ice minimum were ice free during summer, but that happened over centuries, not decades.

https://www.researchgate.net/publication/316697626_Holocene_variability_in_sea_ice_cover_primary_production_and_Pacific-Water_inflow_and_climate_change_in_the_Chukchi_and_East_Siberian_Seas_Arctic_Ocean

[binntho]

Really, is that the weight of the evidence? Show it. Be careful tho, the first links google throws at me are WUWT.


In the mean time, evidence for ice cover throughout the Holocene:

1. Like Today. N84 was ice covered all through the holocene.

https://epic.awi.de/id/eprint/42998/

2.  Unlike 20 years ago and like today, the peripheral seas during Holocene Ice minimum were ice free during summer, but that happened over centuries, not decades.

https://www.researchgate.net/publication/316697626_Holocene_variability_in_sea_ice_cover_primary_production_and_Pacific-Water_inflow_and_climate_change_in_the_Chukchi_and_East_Siberian_Seas_Arctic_Ocean

You keep making a major thing out of the difference in the rate at which a hypothetical BOE happens. I'd suspect that the faster it happens, the smaller it's actual effects (a bit like ripping that bandaid off!)

As I've seen several times, Google does discriminate, and the links I get are mostly from respected publications. Looking a bit more closely I can see that this one is linked several times.

We show that the increased insolation during EHIM has the potential to push the Arctic Ocean sea ice cover into a regime dominated by seasonal ice, i.e. ice free summers.

This one here is interesting, they look at biomarkers from the sea floor up to 90N. Their marker for ice free conditions is IP25 and on page 87 they point out that during the last two or three interglacials, the Arctic Ocean was probably not seasonally ice free, but that the Holocene might have been:

In the high Arctic (>85°N), IP25 was only present during the Holocene.

Here is another that looks at the ridges we've heard about before

We therefore suggest that the occurrence of wave generated shores and abundant ice berg dropped boulders indicate that the Arctic Ocean was nearly free of sea ice in the summer at the time when they were formed. The beach ridges occur as isostatically raised "staircases", and C14-dated curves for relative sea level change show that they were formed in the Early Holocene.

Here is an article focussed mostly on what effects climate change has on the ecosystem, but it does say something about the Holocene and Arctic Ice:

Temporally and spatially variable sea-ice cover throughout the Holocene is among the most notable discoveries of the last decade because it reflects an Arctic Ocean highly sensitive to insolation and unforced climate variability.

[Tom_Mazanec]

If there was an ice free Arctic at any time in the Holocene, is there evidence for weather effects? Like a lot of Sandy superstorms?

[Archimid]

You keep making a major thing out of the difference in the rate at which a hypothetical BOE happens. I'd suspect that the faster it happens, the smaller it's actual effects (a bit like ripping that bandaid off!)

That is extreme nonsense. The faster it happens the worse the effect simply because all living species will have to adapt faster to the changes. The same with all climate change. The faster it happens the worst it is.


Now your links:

https://www.sciencedirect.com/science/article/pii/S0277379113004

We show that the increased insolation during EHIM has the potential to push the Arctic Ocean sea ice cover into a regime dominated by seasonal ice, i.e. ice free summers.162

Yes I know about this model. It makes sense to me and I hope is wrong. If it is right you are very Wrong about a BOE. However a model is not evidence.



Your second link seems to contradict you. At least the part in English. I can't read the other language.

https://pdfs.semanticscholar.org/35a3/d139599ff3e735a81df021ec0ba0af9a0a10.pdf

In the high Arctic (>85°N), IP25 was only present during the Holocene.

"PIP25 index values show a positive correlation with satellite-derived spring/summer sea-ice concentration."

If I'm not mistaken that means that above N84 there was ice, even during summer.

We therefore suggest that the occurrence of wave generated shores and abundant ice berg dropped boulders indicate that the Arctic Ocean was nearly free of sea ice in the summer at the time when they were formed. The beach ridges occur as isostatically raised "staircases", and C14-dated curves for relative sea level change show that they were formed in the Early Holocene.

I can go certainly believe "nearly ice free". However nearly ice free and ice free are two different things.  Ice free conditions means a large departure in surface temperature. Nearly ice free means the surface temperature is held to near the temp of the ice.

[Stephan]

"Your second link seems to contradict you. At least the part in English. I can't read the other language."
The "other language" is German, and this work is almost completely written in English, apart from the 1.25 pages (Summary) written in German...

[binntho]

I may have misunderstood the one about the IP25 - the sentence isn't very clear and the context from which I took it seems to be saying that the other interglacials did not see an ice free Arctic, but that the Holocene had less ice and this is then followed by the statement, "In the high Arctic (>85°N), IP25 was only present during the Holocene."

But as you point out Archimid, the IP25 biomarker is an index of sea ice - but not entirely straight forward. In the section where they discuss the calibration of their method they say:

The occurrence of minimum IP25 concentrations in the high Central Arctic (>85°N) and the Barents Sea may refer to either permanent sea-ice or ice-free conditions. (p. 61)
 

However, they do decide on a PIP25 marker:

The PIP25 index, a combination of IP25 and phytoplankton biomarkers, has been used successfully to estimate sea-ice conditions more quantitatively, showing positive correlations with both spring and summer sea-ice concentrations obtained from satellite observation. (p. 67)

On page 80 we get closer to the Holocene (the last deglacial was a couple of thousand years before the Holocene proper). They conclude year-round ice free conditions in the marginal seas - so a lot less ice than at present:

... consistent with seasonally ice-free conditions during last deglacial ... . Taken together, we postulate the Arctic sea-ice cover was less than the modern sea-ice cover with open-ocean conditions in the marginal seas year round, supporting the minimum sea-ice extent during the last deglacial (16–11kyr BP) as reported by Cronin et al. (2010).

And finally we get to what the say about the Holocene, which isn't much really:

During the last deglacial, the Arctic sea-ice cover was less than the modern sea-ice cover with open-ocean conditions in the marginal seas year around. IP25 was only present during Holocene in the high Arctic (>84°N). (p. 84)

Which I must admit leaves me cluleless as to what they mean.

And finally the discussion bit, where I got my original quote from:

The sea-ice cover was more extensive during MIS 3 and MIS 2 than during the Holocene according to the biomarker data. During the last deglacial, the Arctic sea-ice cover was less than the modern sea-ice cover with open-ocean conditions in the marginal seas year round. In the high Arctic (>85°N), IP25 was only present during the Holocene. (p. 87)

But their article is actually mostly about the Last Glacial Maximum (LGM) and their conclusions (matched by several others) that there was seasonally ice free conditions even during the coldest period of the last ice age, reaching all the way to the shores of Svalbard and parts of the Barents, are to me a major relevation.

[Archimid]

I can certainly agree there must have been periods of ice extent reduction comparable to what we see today, but the evidence indicates that the highest Arctic was ice covered during summer.


I think the most important thing to keep in perspective is the ice sheets at the time of the early holocene



The low Arctic extent was part of the cause for the melt of the laurentide ice sheet, thus much of the heat form the low extent was absorbed by the sheets, much like Greenland absorbs heat (melts) today. This was mostly an astronomical event over thousands of years. Abrupt glacier ruptures could be the basis for Gilgamesh flood and Noah's Ark.

Entire regions had a change of climate because of this, but because it happened over a long time evolution and adaptation happened successfully. By evolution and adaptation  I mean that entire species and civilizations disappeared with the environment changes but over a thousand years nobody noticed, except those who failed to adapt.

[johnm33]

Was there, or was there not, a BOE in the mid-Holocene?

Perhaps you should look up Patricia Sutherlands work and form a view.

[binntho]

The low Arctic extent was part of the cause for the melt of the laurentide ice sheet, thus much of the heat form the low extent was absorbed by the sheets, much like Greenland absorbs heat (melts) today. This was mostly an astronomical event over thousands of years. Abrupt glacier ruptures could be the basis for Gilgamesh flood and Noah's Ark.

This seems to be based on a series of misunderstandings. The "Laurentide ice sheet" in the first picture is simply the rump remains of the much larger ice sheet (the actual "Laurentide") that covered most of North America down to below the Canadian border at LGM (Last Glaciation Maximum).

The rapid melting of this huge glacier (and it's counterpart in Eurasia) simply continued past the images you show - from big to almost non - existent (the Greenland ice sheet was probably the only bit left at the Holocene Maximum, and at that time it was a lot smaller than today).

The causes of the earth going into and out of glacial maximums has nothing to do with whether or not the Arctic is ice free. Mostly it ties in with the Milankovich cycles, but the rapid warming at the end of these glaciations probably also need a kick start from extremely dry weather worldwide.

The tie-in with Gilgamesh and Noah is extremely far fetched. Some have linked it with a flooding of the Black Sea through the opening of the Bosporus some 9000 years ago, others with the Persion Gulf flooding a bit earlier. Both were caused by rising sea waters caused by melting ice. Both can be termed "outburst" floods in a technical sense, but the images you show are showing the famous Lake Agassiz outburst that some think was the cause of the Younger Dryas cold period.

Entire regions had a change of climate because of this, but because it happened over a long time evolution and adaptation happened successfully. By evolution and adaptation  I mean that entire species and civilizations disappeared with the environment changes but over a thousand years nobody noticed, except those who failed to adapt.

Well the whole world went through these huge climate change events during the last 2-3 million years, fluctuating from extreme cold to warm and back to extreme cold every 100.000 years or so. At times, these changes were very rapid, although probably rarely quite as rapid as they are now, but perhaps not that for off either. I'm not sure if anybody has quantified this, but looking at the various graphs it seems that the fastest warming rate at the beginning of the Holocene saw temperatures rise some 4 degrees in perhaps 500 years, or 0.8 degrees per century, compared to our current rate of approximately 1.2 degrees per century.

The big difference of course being that we didn't have 7 billion people living off agriculture the last time the temperatures changed this fast.

[Tom_Mazanec]

Was there, or was there not, a BOE in the mid-Holocene?

Perhaps you should look up Patricia Sutherlands work and form a view.

Do you have a link?

[Archimid]

Bintho, the times and warming rates you speak of require justification, but probably not in this thread. For now I'll ignore you because your argument is OT and almost takes pages out of climate change talking points. I would need two or three posts to debunk all misunderstandings of time scales and evolution that you posted. So I yield, but only out of respect for Tom's work in this forum.

I'll try to TLDR an answer with the hope that real evidence is presented to answer Tom's question: Peripheral seas were likely seasonally ice free, the high latitudes were probably ice covered. Evidence is thin, I presented two links above.

Anyone one with better sources please chime in. I would also like the answer to this stupid question.

[binntho]

Bintho, the times and warming rates you speak of require justification, but probably not in this thread. For now I'll ignore you because your argument is OT and almost takes pages out of climate change talking points. I would need two or three posts to debunk all misunderstandings of time scales and evolution that you posted. So I yield, but only out of respect for Tom's work in this forum.

Well if you don't know anything about the current Ice Age or the last glacial or this interglacial then you might just say that. And talking about respect: Your first response to his question was to call it a "wonderfully stupid question" and then spout some private understanding of BOE that isn't shared by anybody else.

I'll try to TLDR an answer with the hope that real evidence is presented to answer Tom's question: Peripheral seas were likely seasonally ice free, the high latitudes were probably ice covered. Evidence is thin, I presented two links above.

Anyone one with better sources please chime in. I would also like the answer to this stupid question.

I don't think there are better sources, and the ones I've posted show that most likely the Arctic was ice free during the Holocene maximum (the ridging paper basically proves that to my mind, but not for everybody).

But does it matter? Why do you take it so personally when I suggest that the Arctic saw regular BOE's during the Holocene.

[Archimid]

The "wondefully stupid question" was a tongue in cheek reference to the title of the thread. I made clear that I have the same question. If Tom is offended by it, then my apologies, no offense was meant.

On Ice free Arctic during the holocene, you need to read your own links, because they don't say the arctic was ice free, much less with the confidence you imply here, but I'll give you one more with more clear language:

Probably the most spectacular evidence of low-ice Arctic conditions in the early Holocene comes from Northeast Greenland (Fig. 8; Funder and Kjær, 2007; Funder et al., 2009). At this northernmost coast in the world, isostatically raised ‘staircases’ of well developed wave-generated beach ridges investigated along a total coastline stretch of several hundred kilometers document seasonally open water as far north as 83o N. Further north, ridges are short and sporadic, restricted to mouths of embayments and valleys, which suggests that permanent sea ice persisted throughout the Holocene at the northernmost stretch of the coast, near 83.5o
N.

https://www.geo.umass.edu/faculty/jbg/Pubs/Polyak%20etal%20seaice%20QSR10%20inpress.pdf

[Jim Hunt]

I'm not sure if anybody has quantified this, but looking at the various graphs it seems that the fastest warming rate at the beginning of the Holocene saw temperatures rise some 4 degrees in perhaps 500 years, or 0.8 degrees per century, compared to our current rate of approximately 1.2 degrees per century.

If the Younger Dryas Termination counts as "the beginning of the Holocene" then according to Jim White temperatures in North Greenland rose at "~1 °C  per year for 5 years", twice:



P.S. The forum doesn't seem to like starting in mid video. You may wish to start at ~19:00.

[binntho]

If the Younger Dryas Termination counts as "the beginning of the Holocene" then according to Jim White temperatures in North Greenland rose at "~1 °C  per year for 5 years", twice:

Yes, this is a claim that is often heard, mostly by denialists. All claims about the Greenland temperatures based on ice cores are fundamentally flawed - the ice cores are not proxies for estimating Greenland temperatures.

The ice cores (or rather the oxygen isotope ratio) are a proxie for the surface temperature of the area of ocean where the water evaporated that then fell as snow on the glacier. Since most of the evaporates come from the Northern Atlantic, and if the Lake Agassiz outburst cooled that area down rapidly, then the temps from the ice cores will show that.

[Jim Hunt]

If the Lake Agassiz outburst cooled that area down rapidly, then the temps from the ice cores will show that.

How does that theory explain the rapidly rising (proxy) temperatures referred to in the video?

[Archimid]

+1 Jim Hunt

Great talk. It's a shame if anyone misses the first 19 minutes.

I'm a bit confused by his comparison of Greenland temperatures to global temperatures(20:01), but that's a minor quibble relative to how informative this talk is. I learned a lot.

Virtual BOEs happened during the last ice age, even if there was ice above N84. Temperatures shut up significantly, the global climate abruptly changed.