Imagine the yachts of Mornington harbour locked up in meters of thick ice.
Picture our pride and joy, maxi yacht Wild Thing, with its tackle caked in icicles and skipper Grant Warrington clad in fur skins. Imagine yourself down at the Portsea headlands, looking across at the ice blocking the passage of massive container ships trying to get into the once thriving Melbourne Docklands.
‘Impossible!’ you say, but research has shown that just such a scenario probably occurred in Victoria and only a few short centuries ago. What happened?
The “Little Ice Age” period is a scientific reconstruction that includes the time from 1300 AD to approximately 1820 AD when there was a dramatic and erratic climate deterioration. The Little Ice Age is classified into four periods: the Wolf, Sporer, Maunder, and Dalton Minima respectively. They were interspaced with relatively stable periods before. These deteriorations were not only cooler and wetter on average but vastly more erratic.
Such erratic climate extremes are prime ingredients for famine, plague, and the abandonment of human settlements. They followed a period known as the ‘Medieval warm maximum’, which lasted from 900 AD to around 1300 AD That time was much hotter than the present. It was a prosperous era that saw the expansion of the Viking tribes into Iceland, Greenland, Vinland (America), and Russia. Grape vines were grown in warm meadows in what are now cold snowy countries, while great herds of sheep and cattle roamed their now inhospitable coastlines.
The world wide Little Ice Age
However, the Little Ice Age was a global phenomenon. In the Southern Hemisphere, the expansion of the Polynesian peoples occurred From New Zealand to Hawaii and Tahiti. These bold sea peoples resettled the Pacific.
Then, dramatically, the first trough of the Little Ice Age hit with terrible, tragic severity. Erratic minima periods saw the formation of thick sea ice 10 kilometers into the English channel. Major rivers, such as the Thames in London, were frozen for much of the year. Perhaps the River Murray followed suit. The world was hit with particularly severe storms such as the one that wrecked the Spanish Armada in 1588 AD. Glaciers destroyed many prosperous villages. High rainfall and much colder climates were recorded in unstable sequences.
The Little Ice Age plagues and famines
Not coincidentally, the opening thrusts of the Little Ice Age saw a period of major plagues and famines that ravaged Europe and the rest of the world. It was a global phenomenon. The causes were probably the underlying forces that drive weather systems, which Plimer argues are largely due to the influence of sunspot minima. Coronal mass ejections are likely to be another related contributor. These periods of high cosmic ray bombardment cause increased positive ion concentration in Earth’s atmosphere. Fred Soyka claims this causes bacteria to become highly virulent and invasive. Black Death, Plague, and other relentless infections follow.
The plagues and famines attending the Little Ice Age were devastating. Estimates record that the population of the Mediterranean basin was reduced to a third. For instance, the plague of 1347 AD depopulated Europe so badly that it took two hundred and fifty years for it to return to its pre-plague population.
A similar scenario might easily have occurred in the Aboriginal population before white settlement. Archaeologist Hiscock reports that around the 1750s there was significant depopulation of tribes in Australia due to epidemics. This may have been encouraged by the last phase of the Little Ice Age, the Dalton minimum.
The Viking settlement of Greenland became ice bound and the population perished. In Iceland, the population was greatly reduced and became stunted physiologically. Agriculture and fishing had to be largely abandoned. Did similar shocks occur in Australia?
Proof that the Little Ice Age occurred in Australia is forthcoming from many sources. Reconstruction of sea temperatures from Coral cores (Handy et al.), stalagmite isotopic oxygen ratios (Wilson et al.), and Glacial studies in New Zealand (Winkler) confirmed that the Southern hemisphere mimicked the erratic temperature changes of the United States and Europe.
The Little Ice Age conclusion
So where does this lead us? First, as Professor Ian Plimer concludes, the Little Ice Age was in no way due to the hand of mankind. Of equal importance, many scientists contend that the earlier Medieval and Roman warming’s were much hotter than our modern warm period despite lower carbon dioxide levels.
How can we possibly contend that our modern warming is due to mankind and his unwelcome industrial pollution? Fumes and effluent may be obnoxious but they do not cause climate change. The issue is aesthetics not a proven greenhouse effect. Is a proposed Carbon tax a childish waste of time? Do we really think we can control the weather?
Peter Mungo Jupp