8 New Papers Reveal ‘Natural’ Global Warming Reaches Amplitudes Of 10°C In Just 50 Years With No CO2 Influence

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.

Schmidt and Hertzberg, 2011

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.”

dansgaard-oeschger-events-past-80000-years-copy

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.

IPCC AR5 (2013):

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.

Hewitt et al., 2016

“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.”

Rasmussen et al., 2016

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.”

Jensen et al., 2016

“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.”

Agosta and Compagnucci, 2016

“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.”

Olsen, 2016

“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.”

Mayewski, 2016

“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.”

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. 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.”

Shao and Ditlevsen, 2016

“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”

  1. tom0mason

    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.

  2. Duke Silver

    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.

  3. David Appell

    Old news. The US National Academy of Sciences wrote reports on abrupt climate change in 2002 and again in 2013.

  4. David Appell

    tom0mason wrote:
    “These scientists appear to have looked at data…”

    “Without models there are no data.”

    — Paul N Edwards, “A Vast Machine”

    1. Akatsukami

      Without data there are no models

      …except the ones used by warmists.

      1. David Appell

        Akatsukami wrote:
        “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.

    2. AndyG55

      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.

  5. David Appell

    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.”

    1. AndyG55

      ““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.

    2. tom0mason

      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.

      1. David Appell

        tom0mason wrote:
        “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: http://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

        1. AndyG55

          “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.

          1. AndyG55

            EARTH ! darn typos !!

  6. M

    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.

    1. AndyG55

      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.

  7. donb

    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.

  8. Frank

    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.

  9. Bryson