Guest Post by Wim Röst
Introduction
Five million years ago, average temperatures were higher than they are now. During the Pliocene, the era just before the period of the Quaternary Ice Ages, ‘glacials’ did not yet exist because temperatures were too high. As cooling of the deep seas continued, temperatures became that low that large surfaces of the Northern Hemisphere became covered with snow. The earth’s albedo grew fast and large ice sheets started to develop. Only short warm interglacials separated the glacials. The emergence of the interglacials first showed a 41,000-year period (as proposed by Milankovitch) and in the last part of the Quaternary they showed a 100,000-year pattern. A difference that so far is not well understood. Here it is suggested that the continued cooling of deep sea temperatures is the cause of that diminished frequency of interglacials. Colder deep-sea temperatures resulted in lower sea surface temperatures that lowered the atmospheric temperatures. The general background temperature of the Earth became lower and lower, changing climate processes like the glacial – interglacial rhythm. As oceans cooled, atmospheric temperatures lowered and more energy was needed to get out of the glacial state. The extra energy came from combined favourable orbital circumstances, which only happens roughly once in 100,000 years.
5 Million years of ever lower temperatures
As figure 1 shows, during the last 5 million years, deep sea temperatures are falling. This cooling does not seem to be spectacular, deep sea temperatures are going down from an average of plus 2 degrees Celsius to minus 0.25 degrees Celsius, but – as will be argued – this lowering is of the utmost importance for the development of the Earth’s climate. At certain times the lowering of deep sea temperatures is important, even when the lowering is only fractional.
Figure 1: Falling deep ocean temperatures from Pliocene (to the left) into the Pleistocene (to the right in the figure). Time from left to right, in millions of years.
As shown in previous posts, the deep sea is directly connected with the sea surface by a process called ‘ocean upwelling’ sometimes shortened to simply ‘upwelling’. The ever colder deep ocean waters are welling up into the ocean surface layer in large quantities (more than a million cubic kilometres every year). This is a relatively slow process where the cold upwelling waters are warmed by the sun.
But, the lower the starting temperature of the upwelling waters, the colder the surface layer will be. The deep sea cooled more than two degrees Celsius during this period and therefore the sea surface has also cooled.
The world ocean surface comprises 71% of the Earth’s surface and it is generally accepted that the surface (air) temperatures at sea adapt to the temperature of the underlying sea surface water. Therefore, as sea surface waters cool, the atmosphere above 71% of the Earth is cooling. Colder currents will flow to the poles and colder air will be transported to poles and continents, diminishing the warming of those surfaces too. Convection will transport less and colder air upwards. In this way, the colder deep-sea temperatures end up not only in lower sea surface temperatures but also in a colder atmosphere – all other things remaining the same.
Figure 2: Estimate of global surface temperatures from the Pliocene into the Pleistocene, in degrees Celsius. In this figure, we see the same trend in figure 1.
A Deep Sea / Surface temperature Amplifier
It is interesting to see that a two degree C drop in deep sea temperature (figure 1) ends up as a 5 degree C lower surface temperature as shown in figure 2. This is a drop from 17 to 12 degrees Celsius. In this period, we see a large ‘amplification factor’ of around 2.5. A deep-sea temperature that is 0.2°C lower/higher, corresponds with a 0.5°C lower/higher surface temperature. As we shall see, the existence of this ´deep sea / surface temperature amplifier´ is important.
The ‘Earth’s General Background Temperature’
All climate processes on earth are taking place in a setting of a certain background temperature. As argued here, that general background temperature is set by the deep oceans connected with the surface layer that is connected with the atmosphere. The colder deep ocean is the cause of a colder atmosphere. Fluctuations (seasonal, annual, decadal, multidecadal, centennial, millennial) all occur against this ‘background temperature’ of the deep ocean.
The warm deep oceans fifty million years ago had an average temperature of more than 12°C (see figure 3). Those warm oceans created a completely different background temperature than our present deep oceans do. The present average temperature of all our ocean water (inclusive the warm surface layer) is only 3.9°C, the deep oceans themselves are several degrees colder. A difference of around 10°C. Therefore, our present ‘general background temperature’ is very low. Our cold oceans are even allowing glacial periods – that wouldn’t have occurred when the oceans were warmer. Our cold oceans brought us, or perhaps allowed us to have our very cold Pleistocene era. Figure 3.
(Remaining question: what made sea temperatures ending that many degrees lower after 55 million years? More about a possible / probable answer: in future posts)
Figure 3: Estimated deep ocean temperature in the last 65 million years by James Hansen et. al. 2013 Deep sea temperatures were highest 55 million years ago. In the last fifteen million years there is a nearly continuous downward trend.
From here, it is but a small step to find the solution for the 41,000 – 100,000-year problem.
The 41,000 – 100,000-year interglacial problem
During the first period of the Pleistocene interglacials, there was a 41,000-year glacial/interglacial cycle but during the last million years there was only a warmer period once every 100,000 years. See figure 4.
Figure 4: Temperature development in the last five million years according to the Antarctic Vostok Ice Core. The green lines show the 41,000 and the 100,000-year periods in the Pleistocene. The left side of the graph is the warmer Pliocene, the period that was still too warm to permit ice ages.
Milankovitch’ cycles played the dominant role in taking the Earth out of the glacial state. The glacial state is the normal state in the Pleistocene. Eight or nine of every 10 years in the Pleistocene were ‘glacial years’. Very cold. With rough and very changeable weather and climates, as is shown by the high variance in temperature – reflecting frequent and turbulent climate changes.
Javier explains the change in the frequency of interglacials as follows: “The 100 kyr problem is solved because there is no 100 kyr cycle, just a 41 kyr cycle that skips one or two beats.” Italics added.
The question remains: And what causes the skipping of one or two beats?
The answer is: it is the ever lower deep ocean temperature that is translated into ever lower atmospheric temperatures that makes it more difficult to come out of that ever more dominating glacial state. Renee Hannon recently: “The past four glacial cycles are increasing in duration from 89 kyrs to 119 kyrs.”
In the end of the period, because of the extreme cold of the deep sea, only the most favourable (combined) orbital conditions allow a glacial to enter the warmer interglacial state, which has more stable temperatures.
Mechanism
The difference between ‘snow’ and ‘water’ might be only one or two tenths of a degree Celsius. A temperature of + 0.1 °C means ‘melt’ and ‘rain’. A temperature of – 0.1 °C means ‘snow’ and ‘ice’.
The above-mentioned amplification factor comes into mind. Deep sea temperatures relate to (surface) air temperatures but with an amplification factor of around 2.5 for surface air. A 0.2 °C lower deep sea temperature is translated into a half degree Celsius lower atmospheric temperature. Therefore, even a difference of less than one tenth of a degree of the temperature of the deep sea can make a substantial difference in the presence of ice and snow over large Northern Hemisphere land areas. Areas that are covered with ice and snow have a much higher albedo. A rising albedo will further cool the Earth.
In this way, at a certain point, a fractional lowering of deep sea temperatures results in enhanced lowering of the Earth surface temperatures. First, because of the deep sea / surface amplification factor, and second, because of the additional ice and snow albedo amplification.
Once more the development of deep sea temperatures: figure 5.
Figure 5: Glacials and falling deep ocean temperatures from Pliocene into the Pleistocene. Glacials developed from a certain low deep ocean temperature. As cooling continued, interglacials switched their cycle from once per 41,000 years to once per 100,000 years. Added in the figure: squares and the corresponding periods below in the figure.
At the start of the Pleistocene, every obliquity cycle resulted in an interglacial. But later in the period the warming effects by obliquity alone were not enough to compensate the effect of the further cooling deep sea. Some help from other factors (eccentricity, precession and possibly non-orbital factors) was needed to reach that warmer and more stable ‘interglacial state’. As Renee Hannon concludes: “During the last 450 kyrs, the five major warm onsets with rapidly increasing temperatures are triggered by increases in the eccentricity, obliquity, and precession of Earth’s orbit. The nearly concurrent increase in these three astronomical forces appears a necessary component for a major warm onset”. Italics added.
The ‘Earth’s General Background Temperature’ continuously went down. The oceans cooled and processes changed.
Holocene
The oceans gained heat content during the Holocene: deep sea temperatures rose. But since the Holocene Optimum the ocean heat uptake showed a diminishing trend. During the Little Ice Age, the oceans even experienced a net loss in heat content. Important, because now we know at what average temperatures the Earth starts cooling her oceans. Figure 6.
Figure 6: Holocene reconstructions of intermediate water temperatures. (C) Changes in Intermediate Water Temperatures (IWT) at 500 m, and (D) changes in IWT at 600 to 900 m. All anomalies are calculated relative to the temperature at 1850 to 1880 CE. Shaded bands represent T1 SD. Note the different temperature scales. Source: Rosenthal et al.
Future
Only when the trend of continuously falling deep sea temperatures ends, the Earth will continue to be able to get out of a next glacial state. But, if this ever lower deep-sea temperature trend is not changed into a stable or a rising temperature, a ‘constant glacial state’ is what we can expect somewhere in the future.
Then glacials could continue without being interrupted by an interglacial and they could keep the Earth cold for a very long time – millions of years – in a barren glacial state. Which probably will be more severe than our Last Glacial Maximum, because the strong cooling during the glacial trend will not be ended by a warming climate state that could raise the deep-sea temperature to warm the Earth for a longer period.
Perhaps our Pleistocene glacial – interglacial rhythm was just a transition period to a more constant glacial state. The 41,000 → 100,000 trend might indicate such a future.
Conclusions
During the last 15 million years deep sea temperatures were continuously falling. Because of the process of oceanic upwelling the falling deep sea temperatures made sea surface temperatures fall as well. In turn, sea surface temperatures lowered atmospheric temperatures. A small decrease in deep sea temperatures resulted in an amplified surface temperature response. Surface temperatures responded 2.5 times the deep-sea response, such that a 0.2°C cooler deep sea resulted in a 0.5°C cooler surface temperature.
At a certain point, the falling deep sea temperatures resulted in atmospheric temperatures that enabled the development of large scale Northern Hemisphere snow and ice surfaces that increased the albedo of the Earth. That albedo caused a further cooling and resulted in even more snow and ice; another amplifier. Continental ice sheets developed. That was the moment the warm Pliocene terminated and the colder Pleistocene started.
Within the Pleistocene, short warmer and more stable periods – the interglacials – were alternating with glacial periods. During an interglacial the Earth reaches the more favourable ‘normal’ pre-Pleistocene state and is warmer and much more stable. Those interglacials first happened every 41,000 years, but as the deep-sea temperatures (and so atmospheric temperatures) decreased, more favourable orbital circumstances, rather than only increasing obliquity, were needed to get out of the cold glacial climate state. Because of the colder deep oceans during the last part of the Pleistocene the Earth only succeeded every 100,000 years in creating an interglacial.
If the 15-million-year trend of ever decreasing deep sea temperatures is going to continue, somewhere in the future the Earth will not be able to create a next interglacial. Millions of years of a deep and continuing glacial state might be in the future.
With regards to commenting: please adhere to the rules known for this site: quote and react, not personal.
In commenting: please remind you are on an international website: for foreigners, it is difficult to understand abbreviations. Foreigners only understand words and (within the context) easy to guess abbreviations like ’60N’ or ‘SH’.
About the author: Wim Röst studied human geography in Utrecht, the Netherlands. The above is his personal view. He is not connected to firms or foundations nor is he funded by government(s).
Andy May was so kind to read the original text and improve the English where necessary. Thanks Andy!
Very interesting read.
“If the 15-million-year trend of ever decreasing deep sea temperatures is going to continue, somewhere in the future the Earth will not be able to create a next interglacial. Millions of years of a deep and continuing glacial state might be in the future.”
Good question.
Yes, earth’s climatic and temperature evolution is linear. Heidi Cullen’s missing heat is not going to make a heck of difference. Heidi got the process backwards because heidi is not familiar with the fact water more dense than air. 😀
We actually do not know what the future holds on geological time scales, and the past can’t tell you what the future holds due to the linear evolution of earth’s systems.
I would note. 15 million years ago the atmosphere was very different too, the atmosphere is also linearly evolving. Every aspect is, geological evolution, the lot.
Our atmosphere was far shallower in the past, that would surely also affect temperature
The only ting that matters is the Sun’s output. Not much point looking at ANYTHING on Earth. Such observation would be cheap and make nearly all climate “science” unwanted.
Geoff, The sun indeed controls much of our temperature, perhaps not so much in the way you think it does. Old Sol oft stirs up the world in its moods creating many earth-quakes much volcanic activity, mostly hidden from view under the oceans. Most of the worlds underlying warmth comes from the sun stirring our inner planet, this is the real background heat that keeps our planet from being a frozen rock. The sunshine we have each day makes our planet have life and oxygen , not so much to warm it. Go into the desert at sun down the temp will drop from 30 to 40 C to zero in about an hour. The underlying earth is what heats the oceans from the bottom up, depending on the suns moods.
Doesn’t all of this assume the accuracy of the procedure by which we date the glacial/interglacial cycles? What if the cycles themselves are relatively even, and the the “switch” to 100K year cycles is an artifact of a faulty measurement process?
Kurt: “Doesn’t all of this assume the accuracy of the procedure by which we date the glacial/interglacial cycles?”
WR: For example figure 6 shows that the spacing in between the warm periods is larger as time proceeds
Correction: “For example figure 6” must be “figure 5”. Sorry!
But which couldn’t this increase in spacing have come from an unanticipated slow change in the rate at which sediment is deposited on the ocean floor. I looked back at the source of your FIG. 6 and the sediment seems to have come from a channel whose width or depth could have changed over time due to ocean currents.
Kurt: “I looked back at the source of your FIG. 6 and the sediment seems to have come from a channel whose width or depth could have changed over time due to ocean currents.”
WR: Sorry Kurt, my fault, I meant fig. 5.
I’ve been looking through the sources linked in your article, and doing some Google searching, and as best I can come up with, ocean sediments are dated on a simplistic linear assumption that “x” cm equals “y” time interval, say 1cm is 10,000 years or something like that. This assumption seems silly, I can think of all kinds of reasons why the amount of sediment dumped into the oceans would change over time, and I can also imagine that as salinity of the ocean changes, the sediment suspended in the ocean will fall at different rates.
Also, after reading the Jim Hansen paper from which FIG. 5 is drawn, the temperature calibrations for the sediment data (based on oxygen isotope ratios) also include a large number of arm-wavy assumptions that are made, not because they are likely to be true, but because the assumption had to be made in order to proceed and get an answer – any answer.
This kind of stuff may be perfectly acceptable in an academic environment as presenting a hypothesis of historical temperature records, but I don;t think it’s the kind of information a rational person should rely on.
Kurt: “I’ve been looking through the sources linked in your article, and doing some Google searching, and as best I can come up with, ocean sediments are dated on a simplistic linear assumption that “x” cm equals “y” time interval, say 1cm is 10,000 years or something like that.”
WR: There are a lot of questions around proxies. That much, that googling a bit is not sufficient for far reaching conclusions.
The conclusion at the end was primarily directed to Hansen’s penchant for assuming away critical issues related to the quantitative accuracy of his graphs and equations. For example, he indicated that northern latitude sediment data as a proxy for global temperatures likely understated land warming because land temperatures fluctuate more than ocean temperatures. He also indicated that northern latitude sediment data could overstate ocean warming because of its latitude. Then he just brushed both of these questions away by assuming that they canceled each other.
Similarly, Hansen invented the distribution of changes in the sediment proxy data to assign to the period of no glaciation and the period of glaciation (an arbitrary 2-1 ratio as I recall). No particular reason for these numbers were given, he just assumed nonlinearity and implemented it with a 2-1 distribution. You’ve got to admire this guy’s analytical rigor and attention to detail.
I absolutely agree with you – there are a lot of questions around proxies. In all the articles I read, the only ones to bother to indicate how sediment layers are assigned dates at an individual location said that the general method is to assume an unchanging rate of sedimentation and then, if possible, try to verify that assumption using other data, which may or may not be available. And the study I read that purported to combine the sediments from multiple locations into a single chronology first wiped away all the time information in the individual chronologies by shifting and stretching all the chronologies to provide a visual match, and only then tackled the problem of how to draw the time scale on the combined chronology. Once again, there were a lot of unverifiable assumptions made in this whole procedure.
Like I said, if your goal is to use a scientific procedure to posit a reasonable hypothesis on what past temperature change might have looked like, there is nothing wrong with this. But there’s no way to confirm it, and given the assumptions that have to be made in building these chronologies there is no logical reason why anyone should rely on them as being quantitatively accurate along either axis.
One more thing I noticed. If you track back the top panel of FIG. 5 to the source (Hansen) and again click on the download for it to see an enlarged version, the resolution on the time axis gets higher the further back in time you go. That’s really bizarre – I mean just look at all those dark black, closely spaced squiggles five million years ago and compare it to the present.
That instantly sets of an alarm in the back of my head that something is wrong with the time axis – that it’s getting compressed the further back in time you go.
Another great article Wim – the long term reality of where climate is going which the Climagesterium have never once commented on (AFAIK).
What in your view are the underlying reasons for the million year scale secular ocean-driven cooling trend? I can think on the following:
– Oceanic (deep) isolation of Antarctica;
– Push up of the Himalayas from the India collision
– Connection of north and South America separating the Pacific from the Atlantic
– Contracting of the larger more open central Tethys ocean to the present smaller and enclosed Mediterranean;
– Possibly Veizer’s hypothesis that the planet cools as it enters a volume of “dirty” space with higher cosmic particle and radiation flux, to nucleate clouds ☁️ and cool climate.
Thank you ptolemy2!
All of the reasons you mention play their role in the general million scale cooling trend. And there are even more reasons. But my personal choice for the most important one of the by you mentioned options would be “Contracting of the larger more open central Tethys ocean to the present smaller and enclosed Mediterranean”.
In the next post(s) I will explain why. Of course everyone already can make his guesses why this could be the best choice: will be interesting to read. The next post is in preparation, might take a week or so to publish.
One theory is that, as the space between North and South America closed, it forced ocean currents into a more north-south direction. That is thought to have had a huge effect on the climate.
Currently an important way the planet loses heat is by atmospheric and oceanic transport to the arctic where it is radiated to space. Because of ocean and atmospheric currents, and because it is high, Antarctica gets less heat. I wonder if glaciation could cause a similar effect in the arctic. In that scenario the planet would lose less heat through the arctic and would therefore start to warm.
Yes but only the equator would warm, creating more clouds reflecting more sun light, lowering total energy input into the system. Hench a steady state glacation. With warm equatorial regions and cold ice covered northern and southern regions.
Commie,
The climate history of the Cenozoic Era is largely down to tectonics.
The Early Eocene probably enjoyed highest mean annual temperatures of the Era, at about 30° C; with relatively low temperature gradients from pole to pole (equanimity) and high precipitation in an essentially ice-free world.
Land connections existed between Antarctica and Australia, between North America and Europe via Greenland, and probably between North America and Asia across the Bering Strait, despite high sea level. It was an important time of plate boundary rearrangement, in which the patterns of spreading centers and transform faults were changed, causing significant effects on oceanic and atmospheric circulation and temperature.
In the middle Eocene, the separation of Antarctica and Australia opened a deep water passage between those two continents, initiating the Circum-Antarctic Current. This changed oceanic circulation patterns and global heat transport, resulting in the global cooling event observed at the end of the Eocene.
By the Late Eocene, the new ocean circulation resulted in a significantly lower mean annual temperature, with greater variability and seasonality worldwide. The lower temperatures and increased seasonality drove increased body size of mammals, and caused a shift towards increasingly open savanna-like vegetation, with a corresponding reduction in forests.
At the Eocene-Oligocene boundary, the deep channels formed between Antarctica and both South America and Australia led to build up of ice into sheets on the now isolated continent. A passing tectonic plate in the Drake Passage during the Miocene temporarily shoaled the Southern Ocean, causing reduction of Antarctic ice. But it bounced back in the Pliocene and especially Pleistocene.
The drying out of the world however continued in the Miocene and Pliocene, with further spread of grasslands at the expense of forests. In Africa, mammals adapted to grasslands, for example, with the evolution of ruminant artiodactyls, eg antelopes like wildebeest, at the expense of rhinos and zebras, and to ground-dwelling monkeys and apes, leading eventually to baboons and humans.
As you note, around 3 Ma, during the Pliocene, the Inter-American Seaway closed at the Isthmus of Panama. This interrupted circum-tropic ocean current circulation, carrying moisture poleward, leading to the glacial cycle in the Northern Hemisphere.
I should have added that the opening of the Rift Valley also contributed to separating woodier West and Central Africa from grassier South and East. Chimps and gorillas survived west of the Rift, while bipedal hominids dominated the east and south.
I agree with Bill Illis below that the figure I cited of 30 degrees C is too high. But it was hot. Here is the planet at 50.2 Ma:
http://www2.nau.edu/rcb7/50moll.jpg
ptolemy2
Do you have a link to this? It’s something I’ve wondered about since the 1960s and listening to a scifi drama on BBC radio about the earth entering an inter-stellar dust cloud and being invaded by Europans who could deal with deep deep cold. Basically a War of The Worlds scenario, unfortunately I can’t remember how Earth survived.
You’ll probably find it here;
http://www.sciencebits.com/CosmicRaysClimate
Shaviv and Veizer:
http://www.phys.huji.ac.il/~shaviv/Ice-ages/GSAToday.pdf
ptolemy2,
Your last suggestion seems to be conflating two different hypotheses. Veizer’s hypothesis, which is relatively new, does involve cosmic rays/particles. However, there is an even older hypothesis that, as the Earth rotates around the galaxy, it encounters a region that actually has a high enough level of ‘dust’ to dim sunlight.
A newer and hopefully more accurate hypothesis is that global cloudiness is altered by the sun changing ozone concentrations in the stratosphere differently above poles and equator (via wavelength and particle effects on the balance of ozone creation/destruction) so as to alter the gradient of tropopause height between equator and poles when the level of solar activity varies.
Wilde’s hypothesis 🙂
“Deep sea temperatures relate to (surface) air temperatures but with an amplification factor of around 2.5 for surface air. A 0.2 °C lower deep sea temperature is translated into a half degree Celsius lower atmospheric temperature. Therefore, even a difference of less than one tenth of a degree of the temperature of the deep sea can make a substantial difference in the presence of ice and snow over large Northern Hemisphere land areas.”
This doesn’t sound right. There is no reason why deep sea temperature being more or less than 0C should relate to ice and snow on land. With upwelling there is mixing and it won’t be at that temperature when it reaches the surface. And even if it were, the only thing that counts is the amount of cooling it can provide, which is determined by its sensible heat (or lack thereof). The land ice latent heat stabilizes the temperature, but that is not connected with the upwelling being above or below 0C.
It’s worth showing the rest of Hansen’s Fig 3, which shows a dip below zero at the last glacial maximum, but a rise to 1°C now.
.
Nick Stokes: “There is no reason why deep sea temperature being more or less than 0C should relate to ice and snow on land.”
WR: The quoted words above are your words, not mine. Mine are: “Therefore, even a difference of less than one tenth of a degree of the temperature of the deep sea can make a substantial difference in the presence of ice and snow over large Northern Hemisphere land areas.”
It is not important at which deep sea temperatures ice and snow will be formed. The only fact that is important is, that at a certain (!) deep sea temperature the surface becomes that cold that massive ice and snow formation starts. With this in mind, the whole graphic is interesting, indeed.
Wim,
“The quoted words above are your words, not mine.”
Well, your words included:
“The difference between ‘snow’ and ‘water’ might be only one or two tenths of a degree Celsius. A temperature of + 0.1 °C means ‘melt’ and ‘rain’. A temperature of – 0.1 °C means ‘snow’ and ‘ice’.”
If the amplification isn’t related to phase change and associated temperatures, what is it? You’ve mentioned snow albedo, but that is a feedback for any kind of warming. Where does that 2.5 factor come from?
Nick creating straw men again
I’m confused. The portion Nick Stokes quoted (in italics) is in paragraph 2 under the heading ‘Mechanism’. Am I missing something?
Nick Stokes August 13, 2017 at 5:12 am: “Where does that 2.5 factor come from?”
WR: From here in the text: “It is interesting to see that a two degree C drop in deep sea temperature (figure 1) ends up as a 5 degree C lower surface temperature as shown in figure 3”.
Deep sea temperatures are going down two degrees C during this period. The atmospheric consequence over the same period is a 5 degrees lower temperature. For this period as a whole the atmosphere reacts on the colder deep sea (and the lowering sea surface temperatures) with a 2.5 times stronger fall in average surface temperatures. Just reading the graphics.
I see you understand my words “The difference between ‘snow’ and ‘water’ might be only one or two tenths of a degree Celsius. A temperature of + 0.1 °C means ‘melt’ and ‘rain’. A temperature of – 0.1 °C means ‘snow’ and ‘ice’.” as if I am still speaking about average temperatures on a large time scale.
Perhaps I was not clear enough, but I just tried to explain that in daily (!) life small temperature differences at a certain point (!) might have big consequences.
As the deep sea temperatures are related to atmospheric temperatures, in the end even a fractional lower deep sea temperature will bring the Earth to the point that the atmosphere cools that much, that ice ages (glacials) become possible. In fact the question is answered: ‘Can a fractional lower deep sea temperature have a main influence on atmospheric temperatures?’ And the answer is “Yes”. Normally because of the amplification factor the effect of cooling seas on the atmosphere will be larger than we expect. And the more this is the case as snow and ice become involved.
Small changes in the deep ocean temperatures have important consequences for the Earth climates.
Nick is properly looking for a physical explanation of the observed 2.5x amplification. In the context of this paper it would be the nature of the mixing, with the cold abyssal water having a net 2.5x advantage over solar warmed surface water.
For why the abyssal water has been cooling constantly for 55 million years and generally for a hundreed million years since the mid Cretaceous, we eagerly await the next post in this fine series.
Ice ages are far from barren globally. The rising and falling of sea levels from the stadials and interstadials of the Carboniferous ice age produced the sandwich layering of huge coal deposits within alternating marine and terrestrial sediments.
Tropical temperatures remain much the same. It is the tropical to polar temperature gradient that changes.
Good point.
Pablo: “Ice ages are far from barren globally”
WR: “barren” might be ‘cold’ or might be ‘dry’. During the glacials evaporation diminished strongly and the result was that deserts were covering large parts of the planet. Remaining tropical rainforest just covered small parts of the tropics. Ice sheets covered large parts, tundra and deserts covered much of the rest of the world. See for example:
http://www.pnas.org/content/108/15/5925/F1.large.jpg
The map above is obviously from a previous glaciation where the earth’s plants did not have access to enough CO2 to use water efficiently.
Yes, least we forget that humans evolved in warm climates over the last few million years without regard to “average global” temperatures.
I can’t see the logic in this idea surely if cold water upwells from ocean water that is not warmed by sunlight to surface ocean water that is heated by solar radiation then that water will begin to be heated by solar radiation and the water that down wells from the surface water will cool when it is no longer heated by solar radiation the overall temperature of the ocean must depend on the amount of solar radiation entering the ocean and that is all.
Donald Penman “the overall temperature of the ocean must depend on the amount of solar radiation entering the ocean and that is all”.
WR: That is what nearly everyone thinks until now, I think. But on a million year scale other factors play their role. As the last 55 million years the amount of incoming solar radiation did not change that much, other factors have to be important to explain the colder seas. See my next posts.
Obviously there have been massive changes on longer time scales, from hundreds of years (LIA, MWP,etc.) to thousands ( glacial, interglacial) to millions of years (long term cooling, geologic changes, solar evolution, orbital change). In that context we are still just taking baby steps toward a possible comprehensive understanding of the world’s climate and weather.
In most such situations where we seek a deeper knowledge, we start with the big picture. Once we have a reasonable understanding of the major factors we work on the smaller pieces of the puzzle, until we begin to have confidence that we can make and test predictions.
Climate science has very purposefully inverted this process in pursuit of political objectives. Perhaps “perverted”would be a better word. The utter failure of mainstream climate science to recognise the role of the deep oceans in modulating surface climate is just one instance of their purblind obstinance. Another is their failure to recognise that CO2 levels fell as ocean water cooled and they rise as oceans warm. This is a function of solubility but the dead minded chant of the cs Mafia is of course that everything is caused by CO2, CO2, CO2.
I think Wim has provided a well thought out and well presented discussion of information that informs the higher order of questions regarding the science and I found it extremely enlightening and I appreciate his efforts very much!
For my first question I apparently have an answer coming in Wim’s next post.
Second question: How does your hypothesis explain why it is necessary to destroy Capitalism and tear world order to pieces? And how can one get elected (or rich), (your choice), by scaring the begeesus out people with this information?
I’m guessing that the trigger for the cooling of the deep oceans was plate tectonics altering the oceans’ currents? Isn’t it a good job that there are humans on Earth able to create warming and avert another Iceball?
Wim Röst, which parts of this are basic geology and what is your own work here?
‘the Earth starts cooling her oceans. Figure 6.’
Gender of rock found? 🙂
Hugs,
Gaia is generally considered feminine — Mother Earth and all that! Nothing new here, move on.
What’s wrong with ‘it’? I really find it weird to assign gender on some random words. Germans otoh are more logical. They insist everything (well but children) has a gender.
Hugs: “Wim Röst, which parts of this are basic geology and what is your own work here? ‘the Earth starts cooling her oceans. Figure 6.’”
WR: Figure 6 is about cooling oceans during the Holocene. During the Little Ice Age you can see that the green and the blue line dive below 0, which means that the deeper ocean is losing heat.
My work was reading the graphic.
Hum yes, I meant which major parts of the whole story were something you came up with, and which are common knowledge. I can somewhat see that, but not well since I’m not a specialist here.
Hugs: “I meant which major parts of the whole story were something you came up with, and which are common knowledge”
WR: The facts (graphics) that I demonstrate are all well known. But I think I am making many different conclusions on the same facts because I combine them in a different way.
For example, regional (!) temperature and climate effects of cold upwelling are mentioned in the literature, but not the effects of ‘changes in upwelling’ on global temperatures and global climates. There is more attention in the literature for the role of upwelling for fishery.
The long term cooling of the oceans is well known, but the direct and indirect effect on sea surface temperatures and on atmospheric temperatures are not described in the way as I did, at least not as far as I know. The term ‘General Background Temperature of the Earth’ as set by the deep sea temperature is mine, but perhaps something like this is hidden somewhere in the models or elsewhere, I don’t know. For me the fact that I realised that every geological period knows its average atmospheric temperatures as set by the deep oceans was important enough for me to give it a name. Processes change as the background temperature changes.
In general: we know that the oceans play an important role in climate. But how, according to what principles and by what mechanisms is less known. Trying to find it out in my own way I discovered things I did not read about elsewhere. Those things I am writing about.
I don’t know exactly what is described in literature. I am reading literature about subjects, but in the first place I am searching (via Google Images) for maps and figures, graphics and tables about subjects that I think that are interesting and / or important. I try to understand the facts that I find and I try to combine the different information. Where needed I start reading.
I try to understand the oceans with my own feeling for what is logical. And most times I am checking the arising thoughts if possible. Besides that, I am using my own experience with ‘water’. Living in a country (Holland) with a lot of canals and lakes I experienced ‘water’ all my life. Fishing, swimming, sailing, rowing and skating. Building sand castles at the beach during low tide and waiting for the high tide to see them destroyed by the power of water. And not to forget I experienced water by bicycling against wind and rain. I think this all helps to imagine what is happening with water and the elements.
So, to be honest I don’t exactly know what is 100% original mine and what is not. But for me the fact that I nowhere discovered a coherent view on the functioning of the oceans in the way that I can imagine that they do function, is the reason for me to write about it. I try to concentrate on elements that I think that are lacking in (general) knowledge. And are important for understanding ‘climate’.
Here is an article that you may find interesting. Whenever you read about massive ocean heating (e.g., Antarctica, the Arctic), search for the location of undersea volcanoes and vents, as well as local currents. A few years ago, I read an Icelandic oceanographer’s claim that ocean acidification due to climate change had caused codfish stocks to disappear from an area north of Iceland. Sure enough, I checked the geologic maps and the area cited was close to an area of undersea volcanic activity.
http://www.nytimes.com/1995/04/25/science/hot-vents-in-the-sea-floor-may-drive-el-nino.html?pagewanted=all
Clearly all of the money currently being used to subsidize renewable energy sources should be put into fast breeder reactors whose sole purpose is to warm deep ocean water. We’ve probably got enough time to avert the next glaciation if we start immediately. 🙂
Or, we could just decrease the albedo of the ice sheets with more diesel tractors. /sarc
You are not kidding. If we start to get glaciation in North America, the thing to do would be to fly drones over the ice fields and have them deposit carbon dust all over the place.
Wim, would you comment (in your next post) on the possibility that a steady decrease in the “upwelling” of magma through the thin crust of the ocean floor has contributed to steady decline of deep ocean temperatures.
Is there any evidence of a decrease in the amount of new basalt or related rock layers formed in the last 15 million years vs. prior periods of that duration ?
Alternatively perhaps the number of deep sea vents spewing superheated ocean water has declined from millions to the few 100 (?) known today over the course of the last 15 million years.
Would there be any geological evidence remaining of those defunct vents in the deep ocean trenches if that had occurred?
ThinAir: “Wim, would you comment (in your next post) on the possibility that a steady decrease in the “upwelling” of magma through the thin crust of the ocean floor has contributed to steady decline of deep ocean temperatures”
WR: The above is not gonna be subject of my next post. There is a certain warming of the oceans from below, sure. Ben Wouters* calculated that it takes 5000 years to have the temperature of the oceans temperature risen with one degree C. But during that 5000 years of warming, the Earth also has 5000 years to get rid of that extra energy. The process(es) that make the oceans cool or warm are more massive. Under certain circumstances those processes have a final cooling effect, under other circumstances there will be a final warming of the oceans.
* https://wattsupwiththat.com/2016/12/26/warming-by-less-upwelling-of-cold-ocean-water/#comment-2385507
ThinAir August 13, 2017 at 4:53 am
Imo it is the other way around.
The deep oceans were very hot during their creation, since they were sitting on more or less bare magma. Since then their temperatures have been maintained by:
– geothermal flux ( ~100 mW/m^2) capable of warming all ocean water 1K every ~5000 years
– magma at spreading ridges, capable of warming all ocean water 1K every ~200.000 years
– large magmatic events like the Ontong Java one (~100 million km^3).
The first two are reasonably steady, and are balanced by cold water sinking to the ocean floor, presently mostly around Antarctica. The result is a VERY slow cooling apparently (1K every 2-5 million years)
Latest warming occurred prior ~85 mya by a number of large magmatic events. Oceans have been cooling down again since then, interrupted by a few smaller warming events.
Unless another (very) large magmatic event comes along, earth will sink away into a permanent glacial.
So the temperature of the deep oceans is maintained by geothermal energy only, and forms the base temperature to which the sun adds its energy, increasing only the temperature of the upper 200 meters or so.
For reference: 1 million km^3 magma cooling down in the oceans has enough energy to warm ALL ocean water 1K.
see https://tallbloke.wordpress.com/2014/03/03/ben-wouters-influence-of-geothermal-heat-on-past-and-present-climate/
for some more details.
“Some help from other factors (eccentricity, precession and possibly non-orbital factors) was needed to reach that warmer and more stable ‘interglacial state’. As Renee Hannon concludes: “During the last 450 kyrs, the five major warm onsets with rapidly increasing temperatures are triggered by increases in the eccentricity, obliquity, and precession of Earth’s orbit.”
Orbital mechanics most assuredly play a major role in planetary climate, also cycles which the Sun passes through, increased and decreased output on specific wavelengths over decades long periods, would have appreciable effects. We are only now, with orbital based observation/data collection, beginning to gain an understanding of the cycles Sol herself undergoes. Our scientific database concerning Sol is exceedingly meager and her effect on Earth’s climate should not be left out. I look forward to your future posts.
The oceans would get deeper if continents were colliding and forming high mountains out of seabed mantle simply because the area of the earth covered by ocean would be less and the oceans would have less volume heated by solar radiation. A world covered by shallow oceans would be warmer than today where we have the Atlantic and the pacific ocean opening because of plate tectonics.
Just noting that there is a calibration problem in the Figure 3 from Hansen regarding the Eocene temperatures.
The dO18 isotopes that Hansen’s reconstruction comes from, go back billions of years. When you extend this record past Hansen’s cut-off date, you find that the methodology falls apart and you get wildly high temperatures in the distant past for example.
Eocene temperatures were +6.0C not +12.0C and one can see what the problem is in this chart.
Bill Illis: “there is a calibration problem in the Figure 3 from Hansen regarding the Eocene temperatures”
WR: Thank you Bill. It is good to keep your correction in mind. Figures 1,2 and 5 are also from Hansen.
Figure 5 is from Wikipedia. The correct link is the following:
And the text belonging to that figure is:
“Reconstruction of the past 5 million years of climate history, based on oxygen isotope fractionation in deep sea sediment cores (serving as a proxy for the total global mass of glacial ice sheets), fitted to a model of orbital forcing(Lisiecki and Raymo 2005)[2] and to the temperature scale derived from Vostok ice cores following Petit et al. (1999).”
Where have you published your critique of Zachos calibration?
Zachos did it right. Hansen did it it Fake.
Zachos did it right. Hansen did it it Fake.
Really? Zachos shows a temperature of ~12ºC at 50Ma, Hansen shows the same value and quotes Zachos (2001). You show ~5ºC at 50 Ma disagreeing with both Zachos and Hansen so you’ll need to come up with something better than that!
Phil in reaction to Bill Illis: “You show ~5ºC at 50 Ma disagreeing with both Zachos and Hansen so you’ll need to come up with something better than that!”
WR: I am reading all remarks of Bill Illis with much attention. Why? Because he knows what he talks about, he is well informed and he is someone who is searching for the truth, also the truth behind the demonstrated data. Asking questions about the information he gives often leads to an interesting answer. But I suppose that the way the above question is formulated (“you’ll need to come up with something better than that!”) will not stimulate him to give an answer. Which is a missed chance to become better informed.
Interesting, I asked Illis where he had published his critique of the Zachos calibration which Hansen used, instead of ‘better informing’ us Illis came up with ‘Zachos did it right, Hansen did it Fake.’ So we are not going to get ‘an interesting answer’, he has no answer. Hansen and Zachos both get the same answer, a different one from his, without some justification by him my position is that Zachos and Hansen got it right and Illis did it Fake.
Phil. August 16, 2017 at 7:43 am “without some justification by him my position is that Zachos and Hansen got it right and Illis did it Fake”
WR: Phil, without some justification you are taking the position that someone did it fake.
That tells something about your way of working, not about that of Bill Illis.
Wim Röst August 16, 2017 at 8:35 am
Phil. August 16, 2017 at 7:43 am “without some justification by him my position is that Zachos and Hansen got it right and Illis did it Fake”
WR: Phil, without some justification you are taking the position that someone did it fake.
That was Illis’s assertion, he said that despite Zachos and Hansen having the same results that Zachos did it right but Hansen did it fake. He refused to justify his results which differed from theirs so I see no evidence to suggest that Zachos (and Hansen) didn’t do it right.
“As shown in previous posts, the deep sea is directly connected with the sea surface by a process called ‘ocean upwelling’ sometimes shortened to simply ‘upwelling’. The ever colder deep ocean waters are welling up into the ocean surface layer in large quantities (more than a million cubic kilometres every year). This is a relatively slow process where the cold upwelling waters are warmed by the sun.
But, the lower the starting temperature of the upwelling waters, the colder the surface layer will be. The deep sea cooled more than two degrees Celsius during this period and therefore the sea surface has also cooled.”
I’m puzzled why you ignore the equal volume of downwelling waters the effect on the surface temperature will depend on the difference between the temperatures of the downwelling and upwelling fluxes.
A correct statement would be: the deep sea is directly connected with the sea surface by the processes of ocean upwelling and downwelling.
Phil: “A correct statement would be: the deep sea is directly connected with the sea surface by the processes of ocean upwelling and downwelling.”
WR: 10 Points!
So why do you ignore downwelling in your analysis?
Phil: “So why do you ignore downwelling in your analysis?”
WR: My analysis is written down in a series of posts. And I am not yet finished.
WR: My analysis is written down in a series of posts. And I am not yet finished.
They are both parts of the same process how can you treat them separately?
When relatively large quantities of relatively cold water rise to the surface displace relatively large quantities of warmer surface water, it cools the atmosphere and warms the deep ocean. That should be pretty clear. He’s not getting paid by the column inch. If you want a million words of drivel pick up any paper from the “hockey team”. They actually do get paid to write drivel. And lies, I forgot lies. So you get two for the same price with them.
Phil
If you are talking about upwelling and downwelling as just opposites of the same process, in a “what goes up must come down” way, it suggests that you are turning your mind to the phenomenon of oceanic deep circulation for the first time. With extraordinary naivety.
Which I find surprising.
Better late than never to educate yourself – with Wim’s help – that important climatic processes are driven by the ocean, not atmosphere.
ptolemy2 August 14, 2017 at 10:06 am
Phil
If you are talking about upwelling and downwelling as just opposites of the same process, in a “what goes up must come down” way, it suggests that you are turning your mind to the phenomenon of oceanic deep circulation for the first time. With extraordinary naivety.
Far from it, it’s the Continuity equation which is a fundamental tenet of fluid mechanics, and is derived from mass conservation!
Better late than never to educate yourself – with Wim’s help – that important climatic processes are driven by the ocean, not atmosphere.
That continuity applies says nothing about what drives the process. The key fact is that you can not separate the upwelling from the downwelling, the net mass flow must be zero. Take the deep ocean water as your control volume, the outflow to the surface equals the inflow from the surface. Naively assuming that because the upwelling flow is colder than the surface locally does not mean that the balancing flow from say the polar region has to be warmer as Wim does. They can’t be separated.
Phil. August 16, 2017 at 7:27 am: “Naively assuming that because the upwelling flow is colder than the surface locally does not mean that the balancing flow from say the polar region has to be warmer as Wim does.”
WR: “has to be warmer as Wim does”. Please quote my words when you think I have said so.
Downwelling and upwelling equal in volume. But both processes are driven by other mechanisms. Therefore you have to look at them separately.
The difference between ‘snow’ and ‘water’ might be only one or two tenths of a degree Celsius. A temperature of + 0.1 °C means ‘melt’ and ‘rain’. A temperature of – 0.1 °C means ‘snow’ and ‘ice’.
One minor buggaboo in this statement. You forgot the Latent Heat of Fusion. It takes 144 BTUs/# to convert ice to water or water to ice for the state change. In other words once the state change has occurred it takes a lot of heat transfer to switch back, giving a significant time delay for the transition. This delay is the stability of the temperature regime.
Second, you got to the point of recognizing that obliquity gets the earth out of the glacial once every three or four times. You dance around or rather gloss over the inferred reality, that every ice age starts when obliquity drops below 23.5 degrees as we have now. Maybe you will get to that in future discussions. Apologies if I steal your thunder. However, we have a climate emergency about to happen that civilization is NOT ready to handle due to Al Gore’s greed and stupidity.
Looking at the figures presented on glacial and interglacial vegetation cover, the Russians and Iranians are in a terrible climatic bind within their borders. This means they will be forced to either shed population to other countries OR go to war to seize better land to feed their populations. Power = Population, dictators don’t willingly allow their populations to leave because it reduces their power. Russian scientists have already predicted a return of the LIA, so they know what is coming, Crimea was the opening foray.
dscott: “You dance around or rather gloss over the inferred reality, that every ice age starts when obliquity drops below 23.5 degrees as we have now. Maybe you will get to that in future discussions.”
WR: I learned from Javier that it is the drop in obliquity that signals the ending of the interglacials, but with a time delay of 6.500 years. That means that we must ‘soon’ (in geological terms) experience the effect of cooling because of the change in obliquity.
My personal opinion is, that LIA might be the first sign of the enhancing variability that we will see as we are heading into the direction of the next glacial. And the consequent (relatively rapid) warming after the LIA (last century) could be the second sign of a greater variability. We could be warned by that.
Wim
Nice article.
I wrote about the LIA here
https://judithcurry.com/2015/02/19/the-intermittent-little-ice-age/
I was surprised by two things;
Firstly, that the LIA was intermittent rather than the one long deep freeze lasting centuries it is often typified by.
Secondly, by the extremes during the early parts of the period which saw huge variations in temperature even during one season, but certainly over a decade.
By contrast I would say the climate for the last century is rather benign and largely absent of these extremes.
So whether we are seeing the variability you speak of, or whether that has now passed is open to question although in geological terms we MIGHT be on a downward path, in human terms our climate is currently rather stable.
tonyb
Tony, as I wrote in my post “Warm is stable, cold is climate change” more variance (extremes) belong to colder periods. And indeed, our present climate is rather benign. It is the only climate in which we can feed our future 9 billion people: in the glacial state we absolutely could not.
The variability of the cold LIA / Warm 20th Century I am speaking about, is the big wave of colder and warmer average (!) temperatures that is ‘more wavy’ than what we have seen during the thousands of years behind us when Holocene temperatures were higher. Looking at that (!) time scale (thousands of years), variation is augmenting in my opinion. A period of stronger cooling than before (LIA), a period of stronger warming than before (20th century).
dscott August 13, 2017 at 5:28 am
” You dance around or rather gloss over the inferred reality, that every ice age starts when obliquity drops below 23.5 degrees as we have now. Maybe you will get to that in future discussions. Apologies if I steal your thunder. However, we have a climate emergency about to happen that civilization is NOT ready to handle due to Al Gore’s greed and stupidity. ”
While I agreed with your characterization of Algore, a change of one degree in obliquity takes about 8500 years. So I don’t think we have a climate “emergency” regarding glaciation starting, as you claim, when obliquity drops below 23.5 degrees. Plus , as Leif and others point out, eccentricity will be low for the next 40-50,000 years helping to moderate the effect of the lower obliquity and the precession cycles.
Tom in Florida: “Plus , as Leif and others point out, eccentricity will be low for the next 40-50,000 years helping to moderate the effect of the lower obliquity and the precession cycles.”
WR: Tom, just a question. What about the fact that there is (1) a delay in the effect of obliquity and (2) already a cooling down of the oceans during the Little Ice Age?
Although I agree with the thought that tomorrow we are not going to have a climate emergency because of cooling, cooling is a more serious problem than warming and it could be more near than we think, just because of that delay. The ‘deep down’ of the obliquity curve is not felt yet.
Why do you refer to a “delay” in the obliquity effects? According to the obliquity theory of glaciation, as I understand it, when obliquity is less than 23.5 degrees more solar energy is lost to space than is absorbed by the Earth causing cooling in the higher latitudes. When obliquity is higher than 23.5 degrees more solar energy is absorbed by the Earth than is lost to space causing warming in the higher latitudes. The cooling starts exactly when the energy out is greater than energy in. While the balance grows closer to equilibrium as obliquity nears 23.5 degrees (from both directions) until that equilibrium is met, the Earth will continue to heat or cool (again depending on the directional change). So even though the difference becomes smaller and smaller approaching the 23.5 degree mark, the actual change happens at the time the change happens.
Regarding the LIA, there are so many factors involved, some known and some theorized. Tying the LIA to obliquity change seems quite a stretch.
And to conclude, yes I agree that cooling will be the bigger problem than any human induced warming but not in my life time, or my kids, or their kids, or their kids. If allowed, the technology of their times will prevail so not to worry so much.
Tom in Florida: “Why do you refer to a “delay” in the obliquity effects” and “The cooling starts exactly when the energy out is greater than energy in”
WR: That delay is shown in the temperature behaviour of the Earth. Javier wrote about it. Temperatures are going down around 6500 year after obliquity passed its point of highest influence. As the Earth as a whole not directly starts warming as soon as obliquity is going up, it does do the same as obliquity is going down. My guess is that warming has to be translated first in a warming (deep) ocean and second in a cooling (deep) ocean. That takes time, because the oceans are more than 1.3 billion cubic kilometres.
Second, there is a difference in ‘climate state’. The climate state at the cold glacial maximum for example results in less evaporation and so in less clouds. The incoming solar radiation has another effect than when seas are warmer and evaporation higher: there will be more clouds, more reflection. The same sun energy will have a different result.
The same for zonal effects. Heating one place / zone of the Earth will give a different net result in temperature as heating another place / zone of the Earth.
Looking at the final results, Javier concluded that there is a delay of 6500 years between the downturn of obliquity and the final temperature effect.
And about LIA: Earth changes its climate system as insolation changes. Finally, obliquity results in a climate state (cold) that is characterized by a higher variance. Looking at the temperature reconstructions for the Holocene, I think the last centuries already show that higher variance – the first steps. Down and Up.
Javier has been wrong about a lot of things, especially in a post not long ago where he was trying to compare the difference in climate when the orbital parameters of now and 10,000 years ago were nearly the same. He conveniently left out the direction of the change where 10,000 years ago climate was going from cold to warm and now when it is already warm. Still don’t know why you and he insist there must be a lag. It is just a matter of which is dominate, more energy in or more energy out. And we still have about 1700 years before we hit the theoretical equilibrium obliquity of 23.3 degrees. So there is no reason why the Earth should not be still warming slightly. Of course this is a very general point because there is no consideration of the effects of precession and eccentricity included.
The delay is due to the Latent Heat of Fusion. I.e. the change of state from water to ice. Whether it is 6500 or 8500 years, that time scale is to the bottom which is a downward trend in temperatures. Any percentage rounded in whole numbers on the trend to the bottom is going to have very bad effects. The plant hardiness zones will move very quickly toward the equator. The mild cooling of the LIA was a catastrophe in Europe.
Tom in Florida August 13, 2017 at 10:33 am: “”Still don’t know why you and he insist there must be a lag”
WR: This graphic from Javiers Nature Unbound I The Glacial Cycle https://judithcurry.com/2016/10/24/nature-unbound-i-the-glacial-cycle/ shows the temperature lag after obliquity goes down. It also shows that temperatures rise long after obliquity started to rise:
Figure 9
Your figure 4 shows a change in behavior around 3 million years ago, that is about the time when the isthmus of Panama closed, dramatically changed the ocean circulation pattern. See for example:
https://www.nature.com/nature/journal/v393/n6686/full/393673a0.html
Interesting and plausible suggestion for the change to ice ages on a 100,000 year timescale.
As for the underlying background temperature that is determined at any given level of insolation and albedo by the weight of the atmosphere pressing down on the ocean surface.
That weight determines the latent heat of evaporation and so sets the energy content that the ocean must acquire to make evaporation sufficient to balance solar shortwave energy into the oceans with energy losy by the oceans to the atmosphere.
http://www.newclimatemodel.com/wp-content/uploads/2011/11/TheSettingAndMaintainingOfEarth.pdf
Interesting discussion of oceanic effects.
Allan wrote:
“1. Moderate global cooling that is probably imminent, based on the reduced solar activity of SC24 and projections of another weak SC25. Ironically, the warmists have compromised our energy systems just in time for global cooling.”
John Harmsworth wrote:
“Here’s a scenario for us all to consider:
Widespread hunger and food price inflation due to late spring and early fall frosts. Subsidies are removed for ethanol crops and oil prices go up. Fracking and oil sands expansion are demanded for energy security (does anybody seriously think solar or wind is going to work?).
Massive explosion as millions of eco-Socialist heads come apart simultaneously!”
Allan again:
Thank you John H. Your scenario has a good chance of occurring. We made eight predictions in our debate with the Pembina Institute in 2002,and all eight have materialized in those states that embraced global warming mania. In comparison, none of the scary predictions of Pembina and the IPCC have happened – they have a perfect NEGATIVE predictive track record. Hence, nobody should believe anything they say.
We made one more published prediction in 2002 – for moderate global cooling to start in 2020-2030. I hope to be wrong about this cooling, because humanity suffers in cooling climates. However, the weak SC24 and predicted weak SWC25 – neither of which were forecast in 2002 – could very well lead to moderate global cooling.
Regards, Allan
Posted a few days ago – seems relevant:
https://wattsupwiththat.com/2017/08/05/volcanic-northern-winters/comment-page-1/#comment-2573629
Imbecilic politicians and their advisors are obsessing about global warming, when they should be worried about global cooling, both:
1. Moderate global cooling that is probably imminent, based on the reduced solar activity of SC24 and projections of another weak SC25. Ironically, the warmists have compromised our energy systems just in time for global cooling.
2. Longer term, the expectation of another major Ice Age, since we are about 10,000 years into the current interglacial, which is typically followed by ~100,000 years of Ice Age, with continental glaciers advancing over the continents. Dusting the ice sheets with carbon black to change their albedo may actually help avert this catastrophe – no irony there for the demonizers of “carbon”.
3. The recurrence of another major volcano like Tambora in 1815, or Laki in 1783 that would cause significant global cooling and widespread crop losses. Do we have any huge stores of grain that could feed the growing population of Earth in such a crisis? I do not think so. Maybe we could divert the huge USA corn ethanol crop to food production, but that would not be enough.
A major global cooling crisis such as items 2 or 3 could fulfil the objectives of the radical greens to depopulate the Earth of most of humanity – one assumes that they have plans in place such that they will survive.
Regards, Allan
“A major global cooling crisis such as items 2 or 3 could fulfil the objectives of the radical greens to depopulate the Earth of most of humanity – one assumes that they have plans in place such that they will survive.”
Methinks you hit the nail squarely on the head!
Here’s a scenario for us all to consider:
Widespread hunger and food price inflation due to late spring and early fall frosts. Subsidies are removed for ethanol crops and oil prices go up. Fracking and oil sands expansion are demanded for energy security (does anybody seriously think solar or wind is going to work?).
Massive explosion as millions of eco-Socialist heads come apart simultaneously!
Not just solar insolation but also cosmic rays
the cosmic ray flux history can be reconstructed. It exhibits seven clear cycles, which coincide with the seven periods of ice-age epochs that took place over the past billion years. On longer time scales, it is possible to reconstruct the overall cosmic ray flux variations from a changed star formation rate in the Milky Way, though less reliably. The variable star formation rate can explain why ice-age epochs existed over the past billion years and between one and two billion years ago, but not in other eons.
https://www.ias.edu/ideas/2015/shaviv-milky-way
Please explain how cutting CO2 emisions will save us from these events. For extra marks also explain why this means it is necessary to destroy Capitalism and go back to living in caves and supporting and obeying “the smart ones”.
Just kidding.
Alas I lack the knowledge required to critique this hypothesis and so cannot personally be confident as to it’s validity/ invalidity, but it certainly is a stunning idea… a climate ‘theory of everything’. Amazing!
Mr. Julian Forbes-Laird: “a climate ‘theory of everything”
WR: Most of the readers at this website know that the ocean must play a main role in climate. Many reasons already are mentioned but the (total) role of [processes in] the deep ocean is (in my opinion) so far not well understood.
It really is a challenge to come to a new theory in which oceans (and ‘orbit’ and other elements) get the role they deserve. The oceans absolutely are far more important than a trace gas. Sites like this one do a good work in creating this new theory, step by step. Understanding the role of the (deep) ocean in long term changes really will help us. There is more to follow.
Wim- I think it’s an excellent beginning at the macro level. With the oceans holding~1000 X the heat enthalpy of the atmosphere it is obvious that there must be a huge thermal effect . The masses of water that move through the deeps on time frames from tens to hundreds of years strongly indicate significant time lags.
The most (probably the only) critical question in climate science is this: When will the next glacial period begin and how quickly will it develop?
Wim I don’t think that’s a valid mechanism, because the abyssopelagic ocean temperatures at the equator are equal to those of the arctic ocean.
A simple solution for the 100ky cycle is a simple fourier analysis. Then you see that the 41ka cycle continues as before one million years ago. However a strong 100ky cycle is added suddenly. That is probably an CO2 cycle in interaction with earth processes, independent of the Milankovitch cycles and not representing climate.
See for instance: http://climategate.nl/2016/12/16/63447/ (Dutch) and sublinks.
IMO CO2 has nothing to do with the mid-Pleistocene transition.
As the icy epoch progressed, earth got progressively colder,such that every other or just one in three 41 K cycles produced an interglacial. The others were still born.
The average of 82 K and 123 K is about 100 K.
It’s not about averages. There are numerous detailed publications on local conditions during MIS 3 around 50ky that suggest temperatures comparable to today. Let me quote one out of dozens: Sirocko et al 2016; The ELSA-Vegetation-Stack: Reconstruction of Landscape Evolution Zones (LEZ) from
laminated Eifel maar sediments of the last 60 000 years
Apparently it was warm around 50ky ago according to many local studies, and consistent with the 41ka cycle but not according to the ice core isotopes (dD and d18O) and CO2. Hence, it seems that neither represent global climate conditions accurately.
The oldest detailed CO2 records of EPICA go back about 900ka showing a 100Ka cycle dominance. Hence it’s to be predicted that if older detailed CO2 records are to be found, they will not show the 100ky cycle.
Leftturnandre, from the Dutch link you mention: “(..) Dit zijn de effecten van excentriciteit en precessie deze werken elkaar dus tegen. Het effect hiervan is dat alleen de 41.000 jarige cyclus van obliquiteit dominant is voor de variatie van de sterkte van de zonne-instraling.”
WR: In a free translation: “Those are the effects of eccentricity and precession and in this way they neutralize each other. The consequence is that only the 41,000 year obliquity cyclus is dominant for the variation of the intensity of the solar radiation”
André, I don’t think it is that simple. We must look very precisely to the effects of each of the cycles for every zone and region at the Earth. And we must look at the cumulative effects (plural!) of the cycles. There are variations in seasonality which might be very important as well. See my comment https://wattsupwiththat.com/2017/08/13/cooling-deep-oceans-and-the-earths-general-background-temperature/comment-page-1/#comment-2580388 I think the posts of Javier and Renee Hannon (and the comments) are a must-read in understanding the role of orbit.
Leftturnandre: “Wim I don’t think that’s a valid mechanism, because the abyssopelagic ocean temperatures at the equator are equal to those of the arctic ocean.”
WR: It is not clear what you mean with “that’s a valid mechanism”. The (general) mechanism I mention is that the lowering of deep sea temperatures results in [enhanced] lowering of the Earth surface temperatures. I am not talking about specific temperatures at specific places, abyssopelagic or other.
1.3 Billion cubic kilometres of ocean water are moving constantly, not only at the surface but also below, be it more slowly. Ocean (surface) temperatures are translated in atmospheric temperatures. The ocean surface and the deep ocean are strongly connected. Oceans are very dynamic: even average (!) sea surface temperatures anomaly’s change nearly every day, not to talk about daily local and regional differences.
Oceans are dynamic and when we don’t know about their functioning, it is our omission. We must improve our knowledge of the functioning of the oceans and it is of the utmost importance to develop a good theoretical framework for that. I hope my writings will help to develop that framework and will improve insight in the functioning of oceans in relation to climate.
Understanding long term processes will help.
To reduce a gram of water requires the exothermic loss of 1 calories. To turn that gram from water into ice requires almost 80 cal of loss. This threshold effect should slow down if not put this proposed process on hold. Conversely, the state change from ice to water absorbs a lot of energy and should slow/pause a process dependent at least in part on an internal heat source.
If we don’t see the pause, I would expect the deep water portion to be minor. Changes in external heat input would be the determinant. That would include changes in cloud cover also, of course, both ways.
This is a very good post.
Reading through Hansen et al. 2017 (H+ PYTRS A) I am amazed at Hansen’s persistence to apply curve-fitting, scaling and bogus “calibration”, as pointed out, to exemplify his prescribed notions of “sensitivity” and CO2 CH4 “forcing” in order to elevate and gratify his political agenda: “Humanity is now the dominant force driving changes in the Earth’s atmospheric composition and climate.”, “Burning all fossil fuels, we conclude, would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change.”.
Hansen (H+ PYTRS A) is so focused on the “right end” of his plots and no doubt exaggerated in his mind, that the “left end” of his plots “in his mind” diminish to nothingness.