Symposium

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Symposium Monash University
NATURAL CLIMATE CHANGE 24 May, 2009
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The Recent History of Man, and the Influence
of Climate.
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• Throughout the recorded history of Man there have
  been times of
• warm climate, with reliable rainfall and
  prosperity ,
• and times of
• cold climate , with erratic rainfall,
• and with famine and pestilence.
• The great works of Man were built during the
  periods of warmth and prosperity. There was a
  surplus of rural production.
• In the periods of colder climate, crops often
  failed, building ceased, and there was
  migration of peoples from the coldest regions.

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Estimated sea surface temperatures last 3000
years Sargasso Sea sediments.
Warm periods were prosperous
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Ancient Egypt. When the pyramids were being
built, was the climate similar to today?
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Ancient Greece When the Parthenon was built,
was the climate similar to today?
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Ancient Rome At the time of the colosseum,
was the climate similar to today ?
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Rome was a great city, capital of an empire.
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The Roman engineers built great aqueducts for
irrigation and water supply to their
cities. This is an aqueduct in Turkey.
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The Roman Empire flourished in a warm climate,
with reliable rainfall. The rural prosperity
supported large cities, and large armies. The
Roman Empire extended from Jerusalem to the
north of England. The Goths, largely nomadic,
extended over the plains of eastern Europe.
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In 300 AD the weather in Europe
started to become colder. The Goths invaded
Europe. Rome fell !
The accumulated learning of the ancient world
was almost totally destroyed. A few hardy
scholars preserved the precious ancient
writings. Our civilisation was almost lost,
because
of natural climate change!
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By 500 AD, the Roman Empire was ended.

What caused this dramatic change?
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The cold climate of the Dark Ages continued
until about 800 AD. Then the climate became
warmer. The warm period lasted until about the
year 1300. It is known as the Medieval Warm
Period. It was a time of prosperity and
enlightenment in Europe. Many great cathedrals
were built. Universities were founded.
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The Viking explorations and settlements, from 800
to 1000 AD.
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Medieval Warm Period. Prosperity in Europe. Many
great cathedrals were built, eg.Notre Dame,
Wells. There were vineyards in England. The
vikings discovered and settled in a verdant land
they called Greenland. The climate in Europe was
warmer than now!
Notre Dame, Paris.
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The Great Cathedrals of Europe. Wells Cathedral

The Medieval Warm Period from 800 to 1300 was a
time of prosperity in Europe.
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From 1200 to 1285 AD the Mongols advanced into
Eastern Europe, the Middle East, China, Burma,
and India. Was it due to the climate becoming
colder?
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THE LITTLE ICE AGE of over 500 years.
The climate of Europe was mostly cold and
unpredictable from 1315 to 1850. Crops failed
and cattle perished. Famine followed famine,
bringing epidemics . There was fear and
distrust. There was belief that crop failures
were a sign of Gods wrath at human
sin. Witchcraft accusations soared. In France in
1520, fires for the execution of witches blazed
in every town. Inquisitors identified witches.
One took credit in burning 900 in 15 years. In
1563, in Wisensteig in Germany, 63 women were
burnt to death as witches. Today, our
environmental sins have overtaken our spiritual
transgressions as the alleged cause of climate
change. Are we causing climate change?
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1346 1349 The Plague, called the Black
Death The total population of Europe before
the plague
was about 80 million people. It is
estimated that there were 40-50 million deaths,
almost
two-thirds of the population. A contributing
factor would have been the colder climate,
with reduced harvests, making people
less resistant. Many villages were deserted,
and remained so for
over three centuries.
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The Thames froze in many winters from 1607 to
1814. Frost fairs were held. England survived
by the growth of industries, and overseas trade
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Europe 1709 The coldest winter in 500
years. In January 1709 a deadly cold descended
on Europe. The Baltic Sea froze. Lakes and
rivers froze. The soil froze. Livestock
died in the barns. Trees exploded. Fruit trees
died. Birds died by the millions. Travellers
froze to death on the roads. In France, more
than a million people died.
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After the deep cold of 1709 the climate of
Europe became milder, gradually warming to
the benign climate of today. But from time to
time, in the northern hemisphere,
there were occasional winters of intense
cold.
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1812 early Nov. Napoleon retreats from Moscow.
1812 late Nov. Temperatures down to 30
C. Loss of 500,000 men.
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Niagara Falls froze in in 1848
1902 1908, 1909 1911, 1912.
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Exploring the frozen Niagara Falls 1909.
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Niagara Falls 1911
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Skating at Kinderdijk, Jan 2009 Is Europe
becoming colder again?
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What has been the cause of these
changes in the natural climate ? Sometimes the
changes last for one season, sometimes decades,
sometimes centuries. Are they due to variations
in the energy flow to the earth from the sun and
the cosmos?
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What are the natural driving forces ? Does the
electromagnetic dynamo of the sun, and
cosmic electromagnetic radiation, drive the
electromagnetic motor of the earth? If there
is a varying energy input to the earth,
does it influence the speed of rotation of the
earth?
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Changes in the rate of rotation of the earth. In
each day there are 24 hours, of 60
minutes, of 60 seconds, totalling 86,400
seconds. The difference between the
astronomically determined duration of the day
and 86400 SI seconds is called the length of
day (LOD). It has been measured since 1623.
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The oceans cover over 75 of the surface of the
earth. The measurement of the temperature of
the surface of the oceans is now reliable and
extensive. Is there a relationship between
global average sea surface temperatures and
the speed of rotation of the earth, as measured
by the Length of Day?
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• Using a 21 year moving average of the data,
• there is a direct relationship between ,
• the speed of rotation of the earth, (length of
  day) ,
• and,
• global average sea surface temperatures.
• Can that relationship be changed by Man ?

Fin