SOLAR COMETARY & CLIMATIC IMPACTS ON HUMANITY Victor Gostin University of Adelaide Australia
✦ The SUN is our main source of heat and life, and our livelihood depends on its fluctuating activity
SUN through X-RAY eyes
Comet and aurora
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ICE AGES and SEALEVELS
NORTHERN ICE CAP
✦ During the ICE AGES sealevels were low and exposed most of the continental shelves ✦ During the warm periods sea levels were high and drowned the shelves by some 120m [360ft] ✦ Recorded in the ice core from Vostok, Antarctica
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LGM
LGM
✦ Sea temperature history off Santa Barbara plus temperatures in Greenland ice core
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✦ Orbital controls over greenhouse gases
W.F. Ruddiman Sci.Am. March 2005 5
✦ Solar radiation & methane concentrations
W.F. Ruddiman Sci.Am. March 2005
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✦ Orbital cycles & CO2 concentrations
W.F. Ruddiman Sci.Am. March 2005
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HUMAN ACTIVITIES & GREENHOUSE GASES
W.F. Ruddiman Sci.Am. March 2005
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HUMAN ACTIVITIES & GREENHOUSE GASES
W.F. Ruddiman Sci.Am. March 2005
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W.F. Ruddiman Sci.Am. March 2005
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THE GAIA THEORY Since the Earth was born, the Sun’s heat has increased by 25%
The Earth System behaves as a single, selfregulating system comprised of physical, chemical, biological and human components - 2001, the
YET the Earth’s surface temperature has only fluctuated within limits comfortable to life
Amsterdam Declaration
Gaia refers to this self-regulating Earth system: the science of the living Earth as seen from space 11
THE GAIA THEORY ✦ 1989: World Meteorological Org., the UN Environmental Program (UNEP), and the Intergovernmental Panel on Climate Change (IPCC) were established ✦ BUT it was not until the Amsterdam Declaration in 2001 that scientists acknowledged the Earth as a selfregulating entity ✦ What is needed now however, is the goal of sustaining the habitability of our planet James Lovelock 2006 “The Revenge of Gaia” 12
GAIA IN PERIL ✦ Sustaining the habitability of our planet is made most difficult ✦ by the explosion of human population ✦ huge addition of greenhouse gases ✦ reducing biodiversity ✦ replacing natural ecosystems with farmland James Lovelock 2006 “The Revenge of Gaia” 13
GAIA IN PERIL We are currently interfering with temperature regulation by turning up the heat and then simultaneously removing the natural systems that help to regulate it
James Lovelock 2006 “The Revenge of Gaia” 14
Three postglacial “floods” or fast rises of sealevel ✦ All coastal communities were severely disturbed 15
Atlantis in the Celtic Sea? ✦ Drowned by rapid rise in sea level ✦ “Atlantis of the west: the case for Britain’s drowned megalithic civilization” by Paul Dunbavin, 1992 16
The dry Dogger Bank was soon to be flooded
✦ BY 9000 BP THE CLIMATE HAD WARMED AND FORESTS COVERED NW EUROPE ✦ ENGLAND BECAME AN ISLAND 8000 BP 17
TODAY
7150 BP
HOLOCENE
✦ CLIMATE & HUMAN HISTORY ✦ Summary of last 12 000 years for the northern hemisphere 18
5150 BC =7150 BP ✦ Recorded in the ancient legend of Gilgamesh ✦ Later reused in the Hebrew text 19
Profile through the Black Sea shelf
✦ Modern muds covering ancient landscapes with soils
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Human migrations after the Black Sea Flood
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Before the Sahara dried up and people moved to the Nile River valley
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5000-4600 B.P.
Stonehenge was started
✦ First Egyptian dynasty and the great pyramids ✦ At around the same time, in Norte Chico, Peru, cities and pyramids 23
Eastern Mediterranean ✦ Santorini or the island of Thera erupted violently 16271600 B.C. ✦ =3600 before present ✦ It spread a huge fan of volcanic ash over the Eastern Mediterranean. ✦ Ash and sulphuric acid from this event occur in the Greenland ice cap, and frost damage to trees in California.
✦ This ended the flourishing Minoan civilization
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TODAY
COMET COMET COMET COMET COMET
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Mayan cities collapsed in three stages: Green: by 810 AD Pink: by 860 AD Purple: by 910 AD The timing corresponds to severe droughts ✦ Many people survived and their descendents populate the region today ✦ ✦ ✦ ✦ ✦
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TODAY
✦ CLIMATE & HUMAN HISTORY ✦ Summary of last 12 000 years for the northern hemisphere HOLOCENE
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✦ Revealed by the detailed history obtained from the tree-rings of ancient swamp oaks in Europe
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TREE-RING DATING
OLDEST
YOUNGEST
Step-wise means of counting the years when the rings were laid down.
✦ New Scientist May 19, 2001
Swamp oaks back to over 7000 years Bristlecone pine back to 11000 years
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TODAY
COMET COMET COMET COMET COMET
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Fiery Dragons and Celestial Snakes ✦ Legends of dragons (flying reptiles), “celestial snakes” and “feathered serpents” exist in cultures around the world. ✦ The long tail of a comet could be imagined to represent a snake, with multiple, lesser tails being seen as wings. ✦ The association of these creatures in some cultures with destruction and extreme weather, could relate to an ancient ‘close call’ or impact from a comet.
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Comet_McNaught
Lester Barnes, Cummins S.A. 24-1-07
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Chinese Comet Omens
✦ Chinese rulers of the Han dynasty (5th Century BCE) kept an ‘atlas’ of comets to aid in predicting what the appearance of a comet meant. Each comet depicted was accompanied by a description of the omens relating to it. 36
Comets as Bad Omens ✦ Throughout history, comets have been seen as omens of change and disaster in many cultures. ✦ Comets sometimes imagined as swords, or the hair of mourning women, therefore associated with war and death. ✦ Babylonians believed comets presaged all kinds of disasters. Greeks and Romans associated them with bloody warfare. ✦ The appearance of a comet was associated with the birth and death of rulers and with victory and defeat in war. 37
Some Famous Comet Omens ✦ Comets were associated with the deaths of Julius Caesar, Emperor Claudius and with the Civil Wars between Augustus, Pompei and Anthony. ✦ Comet Halley appeared before the Battle of Hastings in 1066 and was considered a good omen by the French (after their victory). ✦ The appearance of a comet encouraged Montezuma to accept, rather than oppose, arrival of Cortez, leading to the downfall of the Aztec empire. 38
From Comet to Swastika? ✦ The swastika: one of the most ancient cross symbols and a widely recognised good-luck symbol before the Nazis. ✦ Ancient Chinese depiction of a comet has a ‘swastika-like’ appearance. ✦ Did an early comet (Encke predecessor?) with multiple jets, give rise to the four-armed symbol found around world?
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Comet Wild-2 (240 km across)
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Stardust spacecraft
C:\WINDOWS\Desktop\BBC NEWS Science-Nature Detailed picture of comet's heart.htm
rare
frequency
common
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IN SUMMARY
✦ Human evolution has been influenced by strong fluctuations in Earth’s climate and sea levels, as well as volcanic and cometary catastrophes. ✦ Lacking scientific explanations to such environmental crises our ancestors have explained these in myths and religions.
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