Climate records from ice cores indicate that abrupt, global-scale warming events with amplitudes of up to 10°C (in the Greenland region) were reached within as little as 50 years dozens of times during the roughly 100,000 years between the last interglacial (~120,000 years ago) and the current interglacial period (11,700 years ago to present). That’s equivalent to a rate of up to 2.0°C per decade of “natural” global warming. CO2 concentrations remained flat and low (~180 parts per million) throughout these warming (and cooling) periods, commonly referred to as Dansgaard-Oeschger events. Schmidt and Hertzberg (2011) provide a summary and (modified) illustration of what these abrupt climatic shifts affecting the “Earth’s climate system” may have looked like.
“Unlike the relatively stable climate Earth has experienced over the last 10,000 years, Earth’s climate system underwent a series of abrupt oscillations and reorganizations during the last ice age between 18,000 and 80,000 years ago (Dansgaard 1984, Bond et al. 1997, 1999). …There are twenty-five of these distinct warming-cooling oscillations (Dansgaard 1984) which are now commonly referred to as Dansgaard-Oeschger cycles, or D-O cycles. One of the most surprising findings was that the shifts from cold stadials to the warm interstadial intervals occurred in a matter of decades, with air temperatures over Greenland rapidly warming 8 to 15°C (Huber et al. 2006). Furthermore, the cooling occurred much more gradually, giving these events a saw-tooth shape in climate records from most of the Northern Hemisphere.”
In contrast to these abrupt and profound warming events in the paleoclimate record, the IPCC indicated in their 5th report (2013) that the surface temperature of the Earth rose by 0.78°C between 1850 and 2012. That’s a warming rate of a little less than 0.05°C per decade.
“The total [global temperature] increase between the average of the 1850–1900 period and the 2003–2012 period is 0.78 °C, based on the single longest dataset available.”
Of course, this 1850-2012 warming period (0.78°C in 160+ years) occurred while CO2 concentrations rose from 280 parts per million (ppm) to nearly 400 ppm.
Putting these records together, it can therefore be concluded that global-scale warming and cooling events occur naturally at rates and amplitudes several times greater (multiple degrees per decade) than what has occurred since 1850 (<0.05°C per decade), and thus climate change in the modern period does not even come close to falling out of the range of what can and does occur naturally. Also, it can be concluded that CO2 concentration changes have historically not been well correlated with abrupt temperature changes either in the paleoclimate record nor during significant portions of the modern period.
Below there are 8 scientific papers published in 2016 referencing these abrupt climate changes, some of which indicate a “global footprint” or “global signature” or “global distribution” of these warming and cooling events.
“Many northern hemisphere climate records, particularly those from around the North Atlantic, show a series of rapid climate changes that recurred on centennial to millennial timescales throughout most of the last glacial period. These Dansgaard-Oeschger (D-O) sequences are observed most prominently in Greenland ice cores, although they have a global signature, including an out of phase Antarctic signal. They consist of warming jumps of order 10°C, occurring in typically 40 years, followed generally by a slow cooling (Greenland Interstadial, GI) lasting between a few centuries and a few millennia, and then a final rapid temperature drop into a cold Greenland Stadial (GS) that lasts for a similar period. … [S]teady changes in ice-sheet runoff, driven by the AMOC, lead to a naturally arising oscillator, in which the rapid warmings come about because the Arctic Ocean is starved of freshwater. The changing size of the ice sheets would have affected the magnitude and extent of runoff, and we suggest that this could provide a simple explanation for the absence of the events during interglacials and around the time of glacial maxima.”
Full paper: http://www.nature.com/articles/srep20535
Press release (sciencedaily): “Extreme climate changes in the past Ice core records show that Greenland went through 25 extreme and abrupt climate changes during the last ice age some 20,000 to 70,000 years ago. In less than 50 years the air temperatures over Greenland could increase by 10 to 15 °C. However the warm periods were short; within a few centuries the frigid temperatures of the ice age returned. That kind of climate change would have been catastrophic for us today. Ice core records from Antarctica also show climate changes in the same period, but they are more gradual, with less severe temperature swings.”
“Proxy data suggests a large variability in the North Atlantic sea surface temperature (SST) and sea ice cover during the Dansgaard Oeschger (DO) events of the last glacial. However, the mechanisms behind these changes are still debated. … Based on our analysis, we suggest that the variability of the subpolar gyre during the analyzed DO event can be explained by internal variability of the climate system alone. Further research is needed to explain whether the lacking amplitude in the Nordic Seas is due to the model deficiencies or if external forcing or some feedback mechanisms could give rise to larger SST variability.”
“The climate in the North Atlantic Ocean during the Marine Isotope Stage 3 (MIS 3) —roughly between 80,000 years before present (B.P.) and 20,000 years B.P., within the last glacial period—is characterized by great instability, with opposing climate transitions including at least six colder Heinrich (H) events and fourteen warmer Dansgaard–Oeschger (D-O) events. … The various theories on the causes include factors internal to the dynamics of ice sheets, and external factors such as changes in the solar flux and changes in the Atlantic Meridional Overturning Circulation (AMOC). The latter is the most robust hypothesis. At certain times, these ice sheets released large amounts of freshwater into the North Atlantic Ocean . Heinrich events are an extreme example of this, when the Laurentide ice sheet disgorged excessively large amounts of freshwater into the Labrador Sea in the form of icebergs. These freshwater dumps reduced ocean salinity enough to slow down deep-water formation and AMOC. Since AMOC plays an important role in transporting heat northward, a slowdown would cause the North Atlantic Ocean to cool. Later, as the addition of freshwater decreased, ocean salinity and deep-water formation increased and climate conditions recovered. During the D-O events, the high-latitude warming occurred abruptly (probably in decades to centuries), reaching temperatures close to interglacial conditions. Even though H and D-O events seemed to have been initiated in the North Atlantic Ocean, they had a global footprint. Global climate anomalies were consistent with a slowdown of AMOC and reduced ocean heat transport into the northern high latitudes.”
“The most frequent abrupt stadial/interstadial changes retained from the marine sediments are known as Dansgaard-Oeschger (D-O) cycles, and appear every 1-2 kyr. These cycles are characterized by abrupt short-lived increase in temperatures (10 ± 5°C) followed by gradual cooling preceding the next rapid event. A second millennial scale feature detected in the sediments record is cooling events culminating significant iceberg discharges analogous to Heinrich events. Mechanisms triggering abrupt changes display uncertainties, but leading hypothesis is attributed to modifications in the Atlantic Meridional Overturning Circulation (AMOC) and deep-water formation initiated by freshwater input.”
“The demonstration using Greenland ice cores that abrupt shifts in climate, Dansgaard-Oeschger (D-O) events, existed during the last glacial period has had a transformational impact on our understanding of climate change in the naturally forced world. The demonstration that D-O events are globally distributed and that they operated during previous glacial periods has led to extensive research into the relative hemispheric timing and causes of these events. The emergence of civilization during our current interglacial, the Holocene, has been attributed to the “relative climate quiescence” of this period relative to the massive, abrupt shifts in climate that characterized glacial periods in the form of D-O events.”
“We reconstructed upper forest line (UFL) positions between ~2000 and ~3400 m elevation and the most abrupt temperature shifts ranged up to 10 °C/100 yr at Terminations II and III. Regional vegetation change is mainly driven by eccentricity (100 kyr) and obliquity (41 kyr) cycles, while changes in local aquatic vegetation show variability in the obliquity and precession (21 kyr) bands. Millennial-scale climate variability reflecting Dansgaard–Oeschger (DO) climate cycles in the upper part of the record, continues in this penultimate intergalcial–glacial cycle strongly suggesting that this variability has a persistent character in Pleistocene vegetation and climate dynamics.”
“The glacial climate is dominated by the strong multi-millennial Dansgaard–Oeschger (DO) events influencing the long-time correlation. However, by separately analysing the last glacial maximum lacking DO events, here we find the same scaling for that period as for the full glacial period. The unbroken scaling thus indicates that the DO events are part of the natural variability and not externally triggered.”
30 responses to “8 New Papers Reveal ‘Natural’ Global Warming Reaches Amplitudes Of 10°C In Just 50 Years With No CO2 Influence”
D. A. will be appalled your quoted papers do not start “We modeled….” or ended with something like “…taken the recent extreme event anthropological global warming is the main driver” And sin of sins the evoked the “natural variability” meme.
These scientists appear to have looked at data, analyzed it, and then either came to a conclusion, or offered a few likely hypothesises, or indeed found that more research was needed. Strangely all the data and methods are available for others to validate and verify, how quaint to use such valid methods of doing science.
Well, they’ve not been ‘peer reviewed’ by the IPCC, Penn State or the U of East Anglia….. so, not accepted by real scientists yet.
Old news. The US National Academy of Sciences wrote reports on abrupt climate change in 2002 and again in 2013.
“These scientists appear to have looked at data…”
“Without models there are no data.”
— Paul N Edwards, “A Vast Machine”
Without data there are no models
…except the ones used by warmists.
“Without data there are no models”
You clearly misunderstand.
Explain how you measure, say, Arctic sea ice extent, without a model.
Or the global surface temperature.
Or your height.
Rotten appell again shows he has zero comprehension about difference between validated engineering models, and climate models that are totally anti-validated and miss the side of a barn.
Stick to fantasy story writing, appell, science is way beyond you.
RUN and HIDE from the truth.. its all you can do.
David Appell citation: “Without models there are no data.”
Internal conversations on models and data reconstructions…
Ray Bradley (co-author of the Michael Mann hockey stick graph): “Furthermore, the model output is very much determined by the time series of forcing that is selected, and the model sensitivity which essentially scales the range. Mike [Mann] only likes these because they seem to match his idea of what went on in the last millennium, whereas he would savage them if they did not. Also–& I’m sure you agree–the Mann/Jones GRL [Geophysical Research Letters] paper was truly pathetic and should never have been published. I don’t want to be associated with that 2000 year ‘reconstruction’.”
[The last two sentences refers to a 2003 paper “Global surface temperatures over the past two millennia” by Mann and Jones, that shows ‘hockey stick’ temperature graphs and was used by the IPCC in its 2007 report.]
Phil Jones (who oversees the Climate Research Unit’s temperature datasets): “I’ve just completed Mike’s Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) amd from 1961 for Keith’s to hide the [temperature] decline.”
Tom Osborn: “Also, we set all post-1960 values to missing in the MXD data set (due to decline), and the method will infill these, estimating them from the real temperatures – another way of “correcting” for the decline [in temperatures], though may be not defensible! “ … “Also we have applied a completely artificial adjustment to the data after 1960”
Keith Briffa [on Michael Mann’s hockey stick graph]: “I have just read this letter – and I think it is crap. I am sick to death of Mann stating his reconstruction represents the tropical area just because it contains a few tropical series.”
Ed Cook replies: “We both know the probable flaws in Mike’s recon,”… “It is puzzling to me that a guy as bright as Mike would be so unwilling to evaluate his own work a bit more objectively.”
Kenneth, if you’re going to quote people, you have to provide links.
Else I can’t verify them, nor look at their context
David, these “hide the decline” ClimateGate quotes are all over the internet from a myriad of sources. You know that, of course, and know full well how to look them up in a web search.
Considering your ostensibly weak track record in matters of honest reporting, no one will be relying on you to faithfully “verify” anything.
You can’t verify anything, you never have been able to. You don’t have the capability.
You have proven that many time.
Still no pics of birds killed by coal fired power station?
For example, the post says
Bogotá-A et al., 2016
“We reconstructed upper forest line (UFL) positions between ~2000 and ~3400 m elevation and the most abrupt temperature shifts ranged up to 10 °C/100 yr at Terminations II and III.
“Reconstructed” means “modeled.”
““Reconstructed” means “modeled.””
Again the rotten appell shows he never did even base level science.
Poor brainless grub !!
I’d say you should stick to fantasy stories, .. except you aren’t even good at that.
Have you got those pics of surface stations or birds killed by coal fired power stations yet.
Still nothing, nada… EMPTY as usual!!
Still RUNNING like the pathetic, ANTI-SCIENCE twerp that you are.
Same old, same old.
Living your comfortable western life, yet preaching CO2 is a problem. The whole ‘CO2 is a pollutant’ is BS with no basis in observed and verified physics.
The eight quoted paper show that this planets changing climate is natural, varying CO2 levels are obviously an effect and not a cause.
“The whole ‘CO2 is a pollutant’ is BS with no basis in observed and verified physics.”
As if you’re at all qualified to make such a determination. You’re not.
“The eight quoted paper show that this planets changing climate is natural, varying CO2 levels are obviously an effect and not a cause.”
Eighth quoted?? Which?
Of course there is natural climate change underneath anthropogenic climate change. If you haven’t understood that, you haven’t understood the most basic parts of climate science.
– See more at: https://notrickszone.com/2016/11/11/8-new-papers-reveal-natural-global-warming-reaches-amplitudes-of-10c-in-just-50-years-with-no-co2-influence/comment-page-1/#comment-1147162
“qualified to make such a determination. You’re not. ”
Yet you, a back-water fantasy writer think anything you say has any scientific meaning. It doesn’t.
You have already proven you can’t back up even the simple statements, just keep running and hiding from them.
Tom0mason is correct. The real science, as opposed to the baseless hypothesis of AGW backs him up completely.
CO2 at any level it can ever reach in the whole atmosphere is nothing but BENEFICIAL to ALL LIFE ON ERATH.
It is NOT a pollution.
EARTH ! darn typos !!
Here is a quote by one of the author’s (Paul Andrew Mayeski) of that report, talking about his book. “The realization that humanity is deeply and irrevocably involved in the short- and long-term fate of a temperamental climate capable of dramatic changes in a matter of only a few years. They also tell of discovering the worldwide reach of industrial emissions; their effects on climate, civilizations, ecosystems, and our individual quality of life.” Please don’t spin the report of a scientist who accepts man made climate change into something used to deny it.
The abstract also says this..
“early manifestation of these events is apparent in the emerging change in the severity and frequency of extreme events.”
ZERO proof, baseless, anti-science, propaganda here-say…
So I agree the paper is a joke not worth considering.
“Please don’t spin the report of a scientist who accepts man made climate change into something used to deny it.”
Even if one believes that the 0.05 C per decade of “global warming” since 1850 has been 100% caused by humans, this tiny warming amplitude and rate doesn’t even come close to falling outside the range of what has routinely occurred naturally and without human interference. In other words, our effect on the climate has been negligible relative to the natural factors affecting climate — even if assuming that all climate changes are caused by humans.
Kenneth Richard wrote:
“Even if one believes that the 0.05 C per decade of “global warming” since 1850 has been 100% caused by humans,”
No one thinks that.
“In other words, our effect on the climate has been negligible relative to the natural factors affecting climate — even if assuming that all climate changes are caused by humans.”
Let’s talk about +0.81 C of warming since 1/1970.
What caused it?
“Even if one believes that the 0.05 C per decade of “global warming” since 1850 has been 100% caused by humans,”
David Apell: “No one thinks that.”
Both John Cook and Gavin Schmidt believe that more than 100% (110% for Gavin, 150% for John Cook) of global warming is caused by anthropogenic CO2 emissions. So where have they gone wrong, David? What percentage is it according to your beliefs, if you don’t believe that changes in deep ocean heat content (where 93% of global warming is contained) are 100% caused by 0.000001 variations in atmospheric CO2? Is it 90% according to you? 80%? Please support your answer, and why you disagree with Gavin and John.
“The best estimate of the warming due to anthropogenic forcings (ANT) is the orange bar (noting the uncertainties). Reading off the graph, it is 0.7±0.2ºC (5-95%) with the observed warming 0.65±0.06 (5-95%). The attribution then follows as having a mean of ~110%, with a 5-95% range of 80–130%.”
“All of these studies find that humans are responsible for close to 100% of the observed global warming over the past 50 years, and human greenhouse gas emissions are responsible for close to 150% of the observed warming, with human aerosol (sulfur dioxide – SO2) emissions offsetting approximately one-third to one-half of that greenhouse warming.”
While calculating your attribution percentage, could you explain why it is that the 65% rate increase human CO 2 emissions (6.1 GtC/yr to 10.1 GtC/yr) between 1992 and 2014 elicited no net change in the CO2 greenhouse effect according to observations? Actually, greenhouse radiative forcing declined slightly (-0.04 W m-2) during this period. So says Song, Wang, and Tang, 2016. For a full explanation with helpful pictures, see the review of a peer-reviewed paper here “New Paper Documents Imperceptible CO2 Influence On The Greenhouse Effect Since 1992”
Song, Wang, and Tang, 2016 “A Hiatus of the Greenhouse Effect”
“The oceanic Gaa [atmospheric greenhouse effect] exhibits a notable increasing trend with a rate of 0.21 W m−2 yr−1 in 1979–1991, whereas its rate of change (−0.04 W m−2 yr−1) during 1992–2014 is not statistically significant.”
David Appell: “Let’s talk about +0.81 C of warming since 1/1970. What caused it?”
Putting aside the satellite-measured temperature record that shows less than half of that temperature change since 1979, and that much of the sea surface data are admittedly “made up” by the dataset procurers, and that the deep 0-2000 m ocean layer (where 93% of global warming presumably caused by humans is claimed to reside) has only been estimated to have warmed by 0.09 C since 1955…
Perhaps these papers referenced in this essay from a few weeks ago will be helpful in your fervent interest in discovering what factors do play a significant role in climate changes:
What role do you think the 2015-’16 El Nino event played in the 2015-’16 temperature increase, David? Or is it your belief that the 0.000003 change in atmospheric CO2 concentration caused anomalous temperatures to rise by 0.7 C and then fall by 0.5 C over the course of the last 15 months? What is the percentage of warming attribution for the 0.000003 CO2 change in 2015-’16 versus the warming attribution for the Super El Nino event? Please support your answer scientifically.
These D-O and H events are measured (mainly in
Greenland ice cores) for the Arctic zone. The northern hemisphere above 60N latitude comprises only 6% of Earth’s surface. I am not aware of global Earth data (i.e., below 60N latitude) indicating anything like 10 deg-C variation in temperature over this time period. As these authors indicate, such large temperature variations were produced by Arctic phenomena. To imply that global Earth temperature varied by 10 deg-C in less than a century is quite misleading.
If you read what was written in the narrative and within the papers themselves closely, it was clearly stated that the abrupt D-O climate changes were global in their scope — though they may not have been entirely in-phase. Decadal-scale lags between hemispheres occurred. Global-scale sea level data also show that sea levels rose at rates of ~2 meters/century between 11,000 and 8,000 years ago, which is much greater than the 7 inches/per century of sea level rise rate since the 20th century began.
3 of the 8 papers mentioned the global scope of D-O changes; the global scale nature of D-O events has become well established in the geological record. See below for a small sampling of some other locations.
Finally, it was clearly stated that the “up to” 10 C changes (actually, sometimes 15 C in a matter of decades) were largely contained to the Arctic region. Other regions of the Earth had less pronounced climate changes (5 C or less within a few decades), but still significantly larger in amplitude and rate than the current +0.05 C per decade and less than 1.0 C change since 1850, or the tenths of a degree net change in the Arctic temperature in the 80 or 90 years since the 1920s and 1930s.
During the last ice age there were several quasiperiodic abrupt warming events. The climatic effects of the so-called Dansgaard-Oeschger (D-O) events were felt globally, although the North Atlantic experienced the largest and most abrupt temperature anomalies. Similar but weaker oscillations also took place during the interglacial period.
While the amplitude of climate change in the Antarctic is generally dampened at best relative to events in Greenland, rapid shifts in climate are not undocumented for the region. At the site of the Siple Dome ice core, near the edge of the Ross Ice Shelf, Taylor et al.  documented a dramatic rise in air temperature of about 6°C 22,000 years ago. This sharp temperature increase apparently occurred within a few decades
Beyond the limited range of historical and instrumental data, the geologic record has provided abundant evidence of natural climate changes that are both abrupt and large in magnitude. The most dramatic insights into this aspect of climate system behavior have come from studies of ice and sediment cores from the northern North Atlantic. Ice core results from Greenland were the first to show that significant changes in regional climate occurred in the past over time scales of a few years to a few decades at most. These excursions, which have come to be known as Dansgaard-Oeschger or D-O events [Dansgaard et al., 1984, 1993], recurred roughly every 1500 years and show up as abrupt warmings over Greenland of as much as 10°C followed by a somewhat more gradual return to cold glacial conditions.
(“Much of the Earth”)
Near-simultaneous changes in ice-core paleoclimatic indicators of local, regional, and more-widespread climate conditions demonstrate that much of the Earth experienced abrupt climate changes synchronous with Greenland within thirty years or less. The temperature estimated for the Younger Dryas… is about 15°C colder than modern, with about half of the temperature change to today having occurred in an abrupt 5-10°C step warming at the end of the Younger Dryas. [T]his 5-10°C warming was abrupt, with much of the change in a few decades or less. Post-Younger Dryas changes [including 20th Century warming] have not duplicated the size, extent and rapidity of these paleoclimatic changes.
The signature of Dansgaard–Oeschger events—millennial-scale abrupt climate oscillations during the last glacial period—is well established in ice cores and marine records. But the effects of such events in continental settings are not as clear, and their absolute chronology is uncertain beyond the limit of 14C dating and annual layer counting for marine records and ice cores, respectively. Here we present carbon and oxygen isotope records from a stalagmite collected in southwest France which have been precisely dated using 234U/230Th ratios. We find rapid climate oscillations coincident with the established Dansgaard–Oeschger events between 83,000 and 32,000 years ago in both isotope records. The oxygen isotope signature is similar to a record from Soreq cave, Israel, and deep-sea records, indicating the large spatial scale of the climate oscillations. The signal in the carbon isotopes gives evidence of drastic and rapid vegetation changes in western Europe, an important site in human cultural evolution. We also find evidence for a long phase of extremely cold climate in southwest France between 61.2 ± 0.6 and 67.4 ± 0.9 kyr ago.
(Venezuela, North Pacific, Arabian Sea)
We present a sedimentary δ15N record from the Cariaco Basin [Venezuela] during marine isotope stage (MIS) 3 (~35–55 ka). The δ15N record displays a pattern of millennial scale variability that tracks the Greenland ice core Dansgaard-Oeschger cycles [abrupt natural climate changes]… [S]triking similarity is observed between the Cariaco [Venezuela] record and millennial scale δ15N records from the ETNP [eastern tropical North Pacific] and Arabian Sea. The apparent synchronicity of changes observed in all three regions suggests an atmospheric teleconnection between the three sites and high-latitude climate forcing during MIS 3.
(central Asia, southern Europe, South America, Indian Ocean)
The climate of the last glacial period is marked by large, rapid variations in climate termed Dansgaard/Oeschger (D/O) events. First identified in the oxygen-isotope values of ice cores from Greenland (1, 2, 3) and interpreted as indicating large temperature variations, correlative climate changes have been identified in a number of high resolution climate records from areas as distant as central Asia (4), southern Europe (5), and South America (6). In the Indian Ocean, marine records of upwelling intensity also show a strong similarity to D/O cycles (7, 8).
“If you read what was written in the narrative and within the papers themselves closely, it was clearly stated that the abrupt D-O climate changes were global in their scope — though they may not have been entirely in-phase. Decadal-scale lags between hemispheres occurred.”
Your two sentences directly contradict on another.
Whatever forcings caused them, there is no reason to think the large forcings we’re imposing today won’t cause them either, or that they won’t be upward and not downward.
We are tickling the dragon’s tail.
“Whatever forcings caused them, there is no reason to think the large forcings we’re imposing today won’t cause them either”
If the “settled science” (basic physics, of course) says that doubling CO2 from 300 ppm to 600 ppm can only cause a direct (no feedbacks) temperature change of 1.2 C at most, and it’s only via strongly positive feedbacks with water vapor and clouds that temperatures reach 3.0 C, how does this indicate that CO2 forcing is just as powerful as the forcings that caused Greenland’s temperatures to rise by 10 C within 50 years?
According to peer-reviewed science (below link), there has been a hiatus in greenhouse forcing from CO2 since 1992. Can you explain why you nonetheless believe that CO2 forcing is “large” enough to cause 10.0 C of warming in 50 years if the radiative forcing from CO2 has such negligible impact within the greenhouse effect?
Rotten Appell continues to live in his FANTASY WORLD.
Cannot back up anything he says..
He KNOWS surface station are an absolute junk pile
and he KNOWS that coal power doesn’t kill birds.
Just make up your FANTASIES as you go, appell-grub.
8 New Papers Reveal ‘Natural’ Global Warming Reaches Amplitudes Of 10°C In Just 50 Years With No CO2 Influence.
Warming in Greenland is not Global Warming.
“These Dansgaard-Oeschger (D-O) sequences are observed most prominently in Greenland ice cores, although they have a global signature, including an out of phase Antarctic signal.
This means that temperatures fell in Antarctica when they rose in Greenland.
We know that oceanic heat transport to the Greenland area depends on cold salty surface water sinking in the Arctic. A large sudden infusion of fresh water (from melting ice) can prevent surface water from sinking, retaining heat in other part of the ocean and cooling the Greenland area Starting and stopping of this process is assumed to be responsible for the large changes in temperature. The sinking of water in the Arctic North Atlantic is part of the meridional overturning circulation (MOC), which reaches into many part of the world’s oceans.
Perhaps you should let the scientists know who have discovered a “global footprint” and “global signature” and “global distribution” with climate effects “felt globally” for the D-O warming events that they are wrong.
See the comment below about near synchronous-with-Greenland D-O warming events being observed in the Middle East, Asia, Indian Ocean, Europe, South America, Antarctica….
“Out of phase” just means they didn’t warm or cool during the exact same time period. This also occurs today. For example, while the Northern Hemisphere was cooling by -0.6 C between 1940 and 1970, the Southern Hemisphere didn’t cool much at all. Antarctica actually warmed some during the 1950s to 1980s, when sea ice area declined. The Arctic cooled by about -1 to -2 C during this same time frame (1940s to 1990s), and sea ice grew relative to the 1920s-’30s warming period. Since the 1980s, Antarctic sea ice has grown, the continent has not warmed, the Southern Ocean SSTs have cooled, and it’s now the Arctic that has had a warming trend and a sea ice decline. So would you call this global warming or not since the “warming” was “out of phase”?
record cooling over land surfaces RSS what if this continues