During the last 2 decades there seems to be a growing number of misconceptions and Theories when evaluating previous Ice Ages, in this paper we look back at the Last five Ice Ages in an attempt to understand Climate and events which preceded them.
Geologically speaking talking about the last 10 million years, the last 10,000 years is part of an extended warm period at the end of a long cooling trend. Geologically there have been several extended hot periods, where the earth was covered in tropical swampy lands with shallow warm seas which changed little for tens of million years- up to around 120 million years. The Mississippian and Pennsylvanian periods best illustrate that, In recent history there have been 5 well documented glacial periods (two more less well documented periods preceded those 5), interrupted by warm interglacial periods.
We can see from the above graph that Glacial periods (in time scales) are getting shorter (Logarithmic bases). So let us take a look at the last 65 million years.
The Vostok Greenland and Antarctic ice cores when analysed year by year show a temperature spike of VERY short duration at the start of major glacial periods. It appears that the start of the glacial period is precipitous, lasting no more than a decade. For example the Dover straits between England and France froze solid in less that a decade at the start of the last Wurm glacial period. That was preceded by a 9°c spike lasting about 20 years, followed by a crash of over 7°c that lead to total glaciation. In the below graph - note the spikes.
When looking at these graphs and evaluating the Peaks and troughs we can see that Le Chatliers Principle is in effect, the Mechanism for the spike and strong reversal. LeChatlier's principle states that any system in equilibrium will react to a change by shifting equilibrium so as to minimize the change.
The warming causes flooding; which in turn causes a new set of ocean currents which then shift weather patterns to a total new track.
The rain winds shift-south to Africa, this creates more cloud cover, rejecting heat over much of Europe. hence it snows, and snows, Snow/Ice cover also reflects incoming heat (solar irradiance) leading to an effective year without a summer. This can build the beginning of a major glacier in half a Decade, leading to a thermal catastrophe. The new equilibrium is then established causing the Sahara to become a fertile grassland; as it did millennia ago, and caused Canada and Scandinavia to be under an ice sheet a half mile deep.
Of course mankind’s understanding of Solar influences in the past 400 years only adds to our understanding of effects and outcomes prior to and preceding glacial and interglacial periods. Recent studies of Solar cycles during the Maunder/Dalton minimum’s 17th/19th century suggest a strong connection to the sun’s Orbit around the Solar system Barycentre, Magnetic strength(sunspots), irradiance (TSI) on much smaller timescales of 11,84,100,206,400yrs, these smaller scaled variations repeat regularly. Unfortunately prior to the 15th century observations in this field were none existent, post 17th Century observations of the solar Corona suggest a strong correlation with recent epochs going back to the Maunder minima of 1645 and Dalton of the 1800’s.
Indeed we are now in the longest “interglacial state” (11.7Kyrs)known to mankind;with the lowest Sea levels and temperatures in History, to go back into a full state of Glaciation temperatures must decrease by at least 3.5-5°c based on Beryllium-10 Carbon-14 Dating. Prior to the interglacial(modern) and at the end of the WURM 18,000K yrs ago “THE CLIMB OUT OF” Glaciation took 6.3K yrs- (sharp temp increase of 6°c from -6c to +0.9c. see graph above), this increase melted the ice in Greenland/Antarctica to current values; with an average Global land/sea temp of 0.90°c. 2017 average Temps 1.05c are lower than any other epoch in history, (NOAA-NASA) temps data used as an unbiased approach.
We can determine from the above that although we have seen an increase in land temps in the decades up to 1998, we now are in a stagnancy, pause. Multi-decadal SST's (sea surface temperatures) play an important role in climatology (PDO-ENSO-MJO-NAO-EPO-WPO-AO), our understanding is only now being realised through a new science (50yrs satellite era).
To arrive at an estimated guess(this is all we have)a new Ice Age could be within the next 1.2K yrs,however the uncertainties are ± 1Kyrs leaving us with a very difficult prognosis, there is NO scientist on Earth that could state either way if we are/not in an imminent state of glaciation, with or without solar values. However if we look at recent history and “repeated” peaks and troughs within the solar field we can ascertain with 80% confidence that we are heading into a short term ( in timescales of decadal yrs +3) drop off in temps of .75-1.15°c, constant with temperatures during the LIA(Little ice age), however this period (according to History) will not sink to values of that during the last glaciation period of -6c as we have not seen over 11,700years an increase in temps of +10c as we did during the Sangamon interglacial (-7 to +3c=10c), these rapid increase/decrease in temps would give us the theoretical evidence of fluctuations in the amount of CO² in the Atmosphere around each Glacial/Interglacial period as our understanding of SST’s suggest oceans distribute CO² during interglacial(warm seas), and retain CO² during Glaciation(cooler seas) we can observe this from the “lag effect” at each stage (5-800 yrs) through 10BE and Carbon-14 dating see below graph.
On closing unprecedented low solar activity(observed) during the last 2 solar cycles present us with a new set of probabilities, low solar activity results in less Atmospheric/Land/Sea irradiance thus resulting in an increasing amount of externally sourced energetic particles(Cosmic Rays), several studies (Svensmark. CERN) have concluded that these energetic particles are modulated with solar activity, I.E. Coronal mass ejections (CME) and SF (Solar Flares) redirect Cosmic rays away from the Magnetosphere, moreover the opposite effects during low solar activity allowing a gradual influx of high energetic cosmic rays; creating fusion to dust and ice crystals forming low cloud cover in the Troposphere. We can see from the cosmic ray database this modulation; presented in a graph below.
Above we can see the very convincing evidence of solar modulation on Cosmic ray influx during the last 3 solar cycles 22/23/24.
Although there is no overwhelming evidence to support an imminent Glaciation, other feedbacks as mentioned in this paper suggest a significant change in Earths Albedo leading to my conclusion of an overall cooling period of -1.5c from 0.9c which equates to -0.6c declining to the year 2030. As this hypothesis is based on actual observed data in this instance, then we must see a significant reduction in solar activity entering into and beyond solar cycle 25/26, if on the other hand this does not happen and solar activity increases then my other hypothesis of glaciation must be considered as temperatures must fall in line with additional irradiance and lower (less) Global cloud cover, this in turn will again see a melt of the polar ice sheets and a shift in zonal air/sea circulations.
With melted ice caps there will be a strong Arctic current that in turn forces the Gulf Stream south to Africa – delivering rain to the Sahara Desert, in N America the stronger North Pacific (Japanese) current flow keeps heat from the Alaska current -not going to Canada, but to the California current, causing warmth there, whilst we see a frigid zone in Canada, outcome- totally different weather patterns.Either way we look at “the picture” it seems we are headed either- in decades or centuries back to a cooler planet, causation Natural cyclic Albedo as seen in the last 1 Million years, whereas the MOC (Meridional Overturning circulation) also known as the Thermohaline circulation flow off the Floridian coast slows down and shifts our into the Atlantic will lead to unprecedented and dramatic disruption of the climate system, consequently leading to an abrupt cooling of the North Atlantic in the sea of Labrador ( see Zonal flows in graph above).
As deep sea waters are displaced upsurge in heat convection applies, however if this zonal stream is effected as surface temperatures plummet density will not be great enough to cause them to sink, thus blocking warmer “deep sea” upsurge, as these upsurges block any formation of ice sheets at the surface then we must definitely prepare for ice cap formation in the North West Atlantic Ocean around the sea of Labrador.
Notes.
1...No two ice ages have presented the same as feedbacks are very different for each, however the causation and effects remain the same.
2...Volcanism remains a key player in Atmospheric Aerosol contamination.
3...Sudden increases in Temperature and gradual melting of Northern Polar ice caps are indicative of pre-glaciation feedbacks.
4...Shifts in Ocean Circulation (Gulf Stream + Alaska + California) "Warning signs".
5... Erratic weather patterns present prior to and following Glaciation.
Thank you for taking time to read my Blog..
prepare for the unexpected and expect change.
David.
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