ago.
So that implies that a
Depending on who you ask, the Little Ice Age began in 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600 or even 1650. There is more agreement as to when it ended; 1850 is the year usually cited, but some would say 1870, 1900, or even 1920.
When people talk about the Little Ice Age (LIA) nowadays, they are mostly interested in the Big Picture: Was the LIA, viewed on some appropriate time scale, a global, a hemispheric or merely a European phenomenon? How much colder was the earth then than it is now? What caused it? Is the Earth warmer now than it was during the 'Medieval Warm Period' that preceded the LIA? And to what extent is that warmth attributable to human activity (changes in albedo as a result of deforestation, or increases in greenhouse gases as a result of factory emissions)?
However, for those writing in the 1632 Universe, the Little Picture is what we need: what is the climate likely to be like in Germany, Italy, France, Scandinavia, England and in other areas of interest,
In the first part of this article, I will provide some background as to the effects that climate can have on human society.
In the second part, I will try to fill in the Little Picture, based on the assumption that the Ring of Fire has
Finally, in the third part, I will consider the Ring of Fire as a meteorological phenomenon, and speculate about how much and for how long it could perturb weather and even climate.
PART I: EFFECTS OF CLIMATE ON HUMAN SOCIETY
Excessive heat and cold can directly threaten human life. In studied regions of England and Wales (1993- 2003 data), it was found that risk of mortality increased by 3% for every degree Celsius above the 'heat threshold' (95th percentile of the mean daily temperature for the region), and by 6% for every degree below the 'cold threshold' (the 5th percentile). In general, heat effects were seen once mean temperature reached 17- 18oC, and cold effect below 5oC. (Hajat). At least in modern Europe and the United States, cold-related deaths are more common than heat-related ones, and that was even more likely to be true in LIA Europe.
The very old and very young, and those in poor health, are the most vulnerable to temperature extremes. However, the human body can adapt over time, which is why we can live in both cold and hot climates.
In addition, there are 'cultural' as well as biological adaptations, and these can work in the short-term. In cold weather, one can wear heavier clothing, or go indoors and build a fire. In the 17th century, there was less that could be done about hot weather, of course. Especially since many Europeans thought that bathing was a bad idea.
Lives may be also be lost as a result of flooding caused by excessive rainfall, if the endangered population cannot flee to higher ground in time. Drought can also kill, if water has not been stored in advance. In hot, dry climates, dehydration is often associated with heat stress.
Even when climate extremes don't kill you outright, they can cause famine, which in turn reduces the body's resistance to infectious disease. 'Malnutrition aggravated an influensa epidemic of 1557-8' (Mandia).
Normal seasonal variations may also have health consequences. Sometime around 400 B.C., Hippocrates declared, 'The changes of the season mostly engender diseases.' The basis for seasonality is not always clear. It may be related to increased pathogen (or disease vector) survival under particular temperature and humidity conditions, increased opportunity for transmission as a result of travel or overcrowding, or reduced host immunity or impairment of other host defenses (e.g., drying of the mucous membrane).
That said, some diseases definitely have seasonal propensities. In autumn and winter, we have influenza; in spring, measles; in summer, malaria (and in modern times, polio). (Dowell). In 1908 Manhattan, scarlet fever and measles were most common in March; there was a higher incidence of death from pneumonia and bronchitis from November through April; death from childhood diarrhea peaked in July-August, and cases of typhoid in August- September (North).
For malaria, the role of climate is well-understood. 'Malaria transmission does not occur at temperatures below 16oC or above 33oC, and at altitudes › 2000m because development in the mosquito (sporogony) cannot take place. The optimum conditions for transmission are high humidity and ambient temperature between 20 and 30oC. Although rainfall provides breeding sites for mosquitoes, excessive rainfall may wash away mosquito larvae and pupae.' (Cook 1202). The northern limit for malaria in Europe has been the 15oC July isotherm (Reiter).
While Europe was colder during the LIA, it wasn't cold enough to prevent malaria. However, a correlation has been reported between high (over 16oC) summer temperatures in Kent and Essex parishes; Reiter speculates that the 'hot weather . . . could certainly have increased the probability of transmission by shortening the extrinsic incubation period (the time required for the mosquito to become infective after feeding on an infected person).'
Yellow fever also is seasonal. In Trinidad, the density of one mosquito carrier was six times more common in the wet season (May-November) than in the dry season; bear in mind that in the tropics; the seasonal variation of temperature is small (Chadee).
Plague is rather more problematic. In Switzerland, 1628-30, the outbreaks were mostly between September and January, with November the month of highest frequency (Eckert). But other outbreaks favored summer, with peaks of mid-summer for Penrith 1597-8, Marseilles 1720, and London 1665, and late-summer for London 1625 and Debrecen 1739 (Welford).
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The climatic deterioration was blamed on human misconduct. In Switzerland, Cysat wrote in 1600, 'Unfortunately because of our sins, for already some time now the years have shown themselves to be more rigorous and severe than in the earlier past. . . .' (Pfister2007).
From blaming sins, it was a short step to looking for sinners. In Treves, Hans Linden's
Accusations of causing 'unnatural weather' or crop failure peaked when climate extremes disrupted agriculture. Moreover, it was generally considered unlikely that a single witch could control weather on a large- scale, which meant that the witch hunts were comparably large in scale (Pfister2007, Behringer).
In the 1620s, in Central Europe, there was a succession of extremely cold summers. For example, on May 24, 1626, there was a hailstorm in Stuttgart, 'which brought hailstones the size of walnuts. . . .' Two nights later, ice formed, and crops failed. Witch-burnings in central Europe rose to a peak of over 500 a year, well above the 'normal' (presumably, non-weather-related) level of the mid-16th century of 100 a year. As late as 1630, 'suspects still had to confess that they had been responsible for the extreme frost in May of 1626.'
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The wealthy, of course, get to choose where they live, and they live where conditions are healthiest. Lamb has pointed out that in Surrey, 20th-century luxury housing is on the hilltops, whereas in the LIA, the
