Transcript little ice age - The Heartland Institute`s International Conferences on

6,000 Years of Humanity’s “little
ice age” Collapses
Dennis T. Avery, Hudson Institute
Heartland 7th Conference on Climate
Change
May 22, 2012
Mayan Swamp Farming
What happened? The Bronze Age Collapse
at 1200 BC
Ice Reveals the 1,500-Yr Cycle
The bad times—
the blue “little ice ages”
Seven Collapses in Today’s Iraq
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Ubaid
3900 BC Drought
Uruk
2900 BC Flood\
Akkadia 2200 BC Drought
Babylon 1600 BC Famine, invasion
Assyria
1200 BC Famine, invasion
Dark Ages 600 AD Famine, Muslims
Little Ice Age 1650 AD Ottoman Empire’s
“17th Century Crisis”
• All of these abrupt climate shifts were global.
Dansgaard-Oeschger:
“moderate” climate cycles?
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Colder (2-4 C)
Shorter, cloudier growing seasons
Megadroughts
Violent floods
Untimely frosts
Locusts
Nomad invasions
Bubonic plague
Bubonic plague epidemics due to
“little ice ages” too
• Rat fleas carry the plague bacteria in arid
western China.
• When megadrought starves “their rats” the
fleas seek new hosts—people, camels
furs, ships.
• Bubonic plagues killed millions during both
the Dark Ages and Little Ice Age.
Shifting Rainfallworst aspect of the “little ice ages”
• Tropical rain belts shift 600 miles south as
Arctic ice expands over centuries.
• Sahara desert moves south
• Europe floods
• China gets drought, floods and locusts
• Eurasian steppes get megadrought, so
nomads invade all neighbors
• Then the rain belts cycle back
17th century famines finally
drive high-yield farming
Ancients’ response to climate change:
the gods were angry
The 1,500-yr Cycle says:
• With high-yield farming, we can feed the people.
• With higher yield farming we need plow no more
wildlands.
• We are more sustainable than the pessimists
believe.
• With agricultural research, we can be more
sustainable than we ever dared believe—until
now.
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We finally know what happened!
• The failed cultures starved due to abrupt
climate change—inflicted by Mother
Nature!
• No lurking flaw in humans.
• No human-induced “tipping points.”
• Just inadequate farm technology in the
past.
We can do even better
Bill Gates has it right:
• Invest in agricultural research
• Use biotechnology
• Use energy miles to transport crops from
where they grow best
• Use more nitrogen fertilizer
• Human sustainability is growing lots of
food per acre!!
But the Anasazi starved during the
Medieval Warming
Megadrought and they lived in forts!
Abrupt climate change can happen
anytime.
!
Restart the high yield farming research
yesterday!!
Books by Dennis
Avery
Climate & Collapse: Abrupt Climate Change
Thru History (forthcoming)
Unstoppable Global Warming--Every 1,500 Yrs
(2007)
Saving the Planet with Pesticides and Plastic
(2005)