Abrupt climate changes and global warming
The major features of ice cores from the Greenland and Antarctic Ice Sheets can be explained within biblical earth history.1,2,3 But these ice cores also show an apparent series of abrupt climate changes. At first these appear to contradict biblical earth history, but volcanism during the post-Flood Ice Age provides a convincing explanation. This ice core data caused a paradigm shift in glaciology4 from gradual to abrupt climate changes and has helped fuel fear of sudden and catastrophic future climate change.
Abrupt climate changes in ice cores.
Abrupt climate changes became evident when glaciologists drilled two ice cores from the top to the bottom of the Greenland Ice Sheet in the early 1990s. Superimposed on the general pattern of inferred temperature showing one Ice Age, about 25 sharp changes were detected (figure 1). Similar changes were not found in Antarctic cores. Based on the greatly stretched-out secular time scale, these represent rapid temperature cooling changes for the Northern Hemisphere, at least in the North Atlantic region, of 10–20°C,5 each lasting an average of about 1,470 years (within the evolutionary timeframe). Many other variables measured in the ice cores are also related to the temperature changes, together indicating major climate change. These fluctuations are named Dansgaard-Oescher (D-O) events, after two prominent researchers.
The most significant aspect of these ‘millennial-scale’ climate oscillations is that the change from one state to another was very rapid:
The demonstration that natural climate variability during the last glacial cycle shifted rapidly between remarkable extremes has dramatically revised the understanding of climate change.6
Abrupt climate changes ‘seen’ in other climate records.
It is amazing that abrupt climate shifts were rarely if ever seen in other post-Flood climate records before the drilling of the two deep Greenland ice cores. But once these ice cores were analyzed, the idea of catastrophic climate shifts took hold. It is interesting that researchers later ‘discovered’ abrupt shifts in many other climatic data sets on land and sea, for instance in deep sea cores and lake pollen data.9 They are also seen in the tropics.10,11 Sarnthein et al. state:
Since these first discoveries from the Greenland Summit cores in the early 1990s, the record of this unexpected climatic behaviour has been found in many regions, including polar ice sheets; marine sediments of the Atlantic, Pacific, and Indian Oceans; and in terrestrial lakes and bogs.12
I wonder, are we witnessing another example of the ‘bandwagon effect’, where deductions from one data set are ‘seen’ in other data sets?13 Or, perhaps they were not seen because of their previous assumptions.
The cause unknown.
Secular scientists do not know the cause of these abrupt and truly radical climate changes, which has led to much speculation and debate:
One of the most enigmatic and energetically debated problems in paleoclimate research continues to involve the development of a consensus theoretical understanding of the mechanisms that underlie the millennium time-scale oscillations of glacial North Atlantic climate.14
Dfijfhout and colleagues admit that climate models rarely demonstrate such shifts:
Abrupt climate change is abundant in geological records, but climate models rarely have been able to simulate such events in response to realistic forcing.15
Fuelling global warming alarmism
Secular scientists suggest that the temperature passing some ‘threshold’ results in such abrupt climate change into a new stable climate state—radically colder or radically warmer. Some have even suggested that the current global warming trend could be such a ‘trigger’, once Earth crosses a certain warming threshold, for causing catastrophic climate change. This is one reason so many scientists and laypeople alike are extremely concerned about current global warming, despite it being only about 1°C, over half of it due to natural processes.16,17
Kendrick Taylor states: “It is ironic that greenhouse warming may lead to rapid cooling in eastern North America, Europe and Scandinavia …”18 Because the ‘next’ ice age is supposedly due soon, others claim: “But warming could lead, paradoxically, to drastic cooling—a catastrophe that could threaten the survival of civilization.”19 So, abrupt climate change records have fuelled global warming alarmism.
Abrupt climate changes can be explained by the post-Flood Ice Age.
I have suggested several times in the past that drastic climate changes were real and caused by decadal changes in volcanism.2 Numerous layers of volcanic ash, tephra, and acid are found in the Ice Age portion of the Greenland ice cores.20 A timescale measured in decades means that the oscillations can vary from a few years to several tens of years. The decadal-scale peaks and lulls are superimposed on a general decrease in volcanism with time during the Ice Age (figure 2).
While working on the Ice Age, I discovered that the amount of volcanic ash and very fine particles (aerosols) in the upper atmosphere (reflecting sunlight back into space) controlled the rate of ice sheet growth. During periods of strong volcanism, colder temperatures result in greater snowfall. The opposite happens during volcanic lulls. These temperature changes can be correlated to many other variables that change at the same time. Some secular scientists likewise propose that the D-O events could be caused by volcanism.21
Antarctica only shows seven to nine climate changes during the Ice Age, but these represent changes of only 1–2°C that are slow, not abrupt. The differences between the abrupt changes in the Greenland Ice Sheet and the weak changes in the Antarctic Ice Sheet are attributable to different amounts of volcanism in the Northern and Southern Hemispheres, respectively.22 Since the latitude where volcanism takes place greatly affects the subsequent global cooling, fewer large eruptions in the Southern Hemisphere may be why the climate changes were fewer, and unimpressive compared to the Northern Hemisphere. This is supported by a simulation of a Northern Hemisphere eruption that generated “an aerosol plume that is strictly confined to the Northern Hemisphere in the months following the eruption, with no direct radiative forcing on the tropical zone.”23 In other words, volcanism in the Northern Hemisphere does not change temperatures in the tropics, so logically would not cause temperature changes in the Southern Hemisphere.
Abrupt climate changes unlikely to occur today
Abrupt climate changes occurred only during the Ice Age caused by the Genesis Flood. The recorded temperature oscillations are associated with the highs and lows in a period of active global volcanism. Therefore, they give no support to the idea that abrupt climate changes caused by global warming or some other mechanism are likely to occur today.24 The samples of ice that accumulated after the Ice Age from the tops of both Antarctica and Greenland cores show only minor fluctuations, but no significant climate changes since the Ice Age. Wunsch states: “Connection of D-O events to the possibility of modern abrupt climate change rests on a very weak chain of assumptions.”25
References and notes
- Oard, M.J., Antarctic and Greenland Ice Sheets explained within biblical earth history, creation.com/antarctic-and-greenland-ice-sheets, 16 October, 2022. Return to text.
- Oard, M.J., Ice core oscillations and abrupt climate changes: part 1—Greenland ice cores, J. Creation 34(3):99–108, 2020; creation.com/ice-core-oscillations-1. Return to text.
- Oard, M.J., Ice core oscillations and abrupt climate changes: part 2—Antarctic ice cores, J. Creation 35(1):70–71, 2021; creation.com/ice-core-oscillations-2. Return to text.
- Glaciology is the study of glaciers and ice. Return to text.
- Oard, M.J., Wild ice-core interpretations by uniformitarian scientists, J. Creation 16(1):45–47, 2002; creation.com/wild-ice. Return to text.
- Rohling, E.J., Mayewski, P.A., and Challenor, P., On the timing and mechanism of millennial-scale climate variability during the last glacial cycle, Climate Dynamics 20:257–267, 2003. Return to text.
- Pausata, F.S.R., Legrande, A.N., and Roberts, W.H.G., How will sea ice loss affect toe Greenland Ice Sheet? EOS Trans. American Geophysical Union 97(9):10, 2016. Return to text.
- Hammer, C., Mayewski, P.A., Peel, D., and Stuiver, M., Preface to special volume on two Greenland ice cores, J. Geophysical Research 102(C12):26,315–26,316, 1997. Return to text.
- Oard, M.J., A tale of two Greenland ice cores, J. Creation 9(2):135–136, 1995; creation.com/two-ice-cores. Return to text.
- Pahnke, K., Zahn, R., Elderfield, H., and Schulz, M., 340,000-year centennial-scale marine record of Southern Hemisphere climatic oscillations, Science 301:948–952, 2003. Return to text.
- Rashid, H., Understanding the extent and ccauses of abrupt climate change, EOS Trans. American Geophysical Union 90(42):376, 2009. Return to text.
- Sarnthein et al., Exploring Late Pleistocene climate variations, EOS Trans. American Geophysical Union 81(51):625, 2000. Return to text.
- Oard, M.J., Ancient Ice Ages or Gigantic Submarine Landslides? Creation Research Society Books, Chino Valley, AZ, pp. 11–13, 1997. Return to text.
- Vettoretti, G. and Peltier, W.R., Fast physics and slow physics in the nonlinear Dansgaard–Oeschger relaxation oscillations, J. Climate 31:3,423, 2018. Return to text.
- Dfijfhout, S., Gleeson, E., Dijkstra, H.A., and Livina, V., Spontaneous abrupt climate change due to an atmospheric blocking—sea-ice—ocean feedback in an unforced climate model simulation, Proc. National Academy of Science 110(48):19,713, 2013. Return to text.
- Oard, M.J., Wonders of Creation—the New Weather Book, Master Books, Green Forest, AR, 2015. Return to text.
- Batten, D., Anthropogenic Global Warming (AGW)—a biblical and scientific approach to climate change, creation.com/climate-change, 17 Aug 2022. Return to text.
- Taylor, K., Rapid climate change, American Scientist 87:326, 1999. Return to text.
- Calvin, W.H., The great climate flip-flop, Atlantic Monthly 281(1): 47, 1998. Return to text.
- Oard, M.J., The Frozen Record: Examining the Ice Core History of the Greenland and Antarctic Ice Sheets, Institute for Creation Research, Dallas, TX, p. 129, 2005 (available from ICR by print on demand). Return to text.
- Baldini, J.U.L., Brown, R.J., and McElwaine, J.N., Was millennial scale climate change during the Last Glacial triggered by explosive volcanism? Scientific Reports 5(17442):1–9, 2015. Return to text.
- Toohey, M., Krüger, K., Schmidt, H., Timmreck, C., Sigl, M., Stoffel, M., and Wilson, R., Disproportionately strong climate forcing from extratropical explosive volcanic eruptions, Nature Geoscience 12:104, 2019. Return to text.
- Pausata, F.S.R., Chafik, L., Caballero, R., and Battisti, D.S., Impacts of high-latitude volcanic eruptions on ENSO and AMOC, Proc. National Academy of Science 112(45):13,784, 2015. Return to text.
- Oard, M.J., The Great Global Warming Debate (DVD), CMI, 2011 Return to text.
- Wunsch, C., Abrupt climate change: an alternative view, Quaternary Research 65:191–203, 2006. Return to text.