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| Credit: David Hawgood |
So I discussed the Lost Civilization ("Atlantis") with mi amigo ChatGPT...
Was the climate during the "last Ice Age" (and before that) too unstable for agriculture to develop? Is this a good argument against the Lost Civilization speculations of Graham Hancock and others?
Yes — the climate during the Last Glacial Maximum (LGM) and much of the preceding Ice Age was indeed too cold, dry, and unstable to support agriculture at any meaningful scale, and this is one of the strongest empirical arguments against the "Lost Civilization" theories advanced by Graham Hancock and similar authors.
Here’s how we know that, and why it matters:
🌍 1. Climate During the Last Ice Age (ca. 115,000–11,700 BCE)
🔹 Harsh Global Conditions
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The Last Glacial Maximum (LGM) peaked around 21,000 years ago (ca. 19,000–23,000 BCE).
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Vast regions of the Northern Hemisphere were covered in ice.
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Sea levels were ~120 meters (400 feet) lower.
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Most of Europe and North America were inhospitable tundra or steppe.
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Rainfall was drastically reduced in many places due to glacial atmospheric patterns.
🔹 Extreme Instability
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Ice Age climate included frequent and abrupt shifts, such as:
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Dansgaard-Oeschger events: rapid warming periods (~5–8°C increase in decades) followed by cooling.
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Heinrich events: massive ice discharges into oceans, disrupting currents and climate.
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These shifts made long-term plant cultivation virtually impossible, because seasonality and precipitation were unpredictable.
🌾 2. When and Why Agriculture Emerged
🟢 Agricultural Revolution: ~11,700 years ago
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Occurred at the start of the Holocene, a warm, stable period following the Ice Age.
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Agriculture first developed in the Fertile Crescent (e.g., wheat, barley, lentils) around 9600–8500 BCE.
🧪 Scientific Consensus:
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Agriculture required a predictable climate with:
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Regular seasons
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Reliable water sources
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Sufficient warmth and growing periods
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These conditions did not exist during the Ice Age, especially during the LGM.
🧱 3. Implications for “Lost Civilization” Claims
🔍 Graham Hancock's Theory (simplified):
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Claims that an advanced global civilization existed during or before the Ice Age.
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Suggests it was destroyed by a cataclysm (like comet impacts) ~12,800 years ago.
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Proposes that it left behind megalithic structures and cultural knowledge.
❌ Problems with This Theory:
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No evidence of agriculture or urban settlements during the Ice Age.
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No archaeological traces of metallurgy, cities, writing, or food production systems from this period.
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Every known complex civilization (Mesopotamia, Egypt, Indus Valley, etc.) emerged long after 4000 BCE, when the climate was stable.
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Structures like Göbekli Tepe (~9600 BCE) are impressive, but show hunter-gatherers building ritual sites — not evidence of an advanced lost culture.
🔬 4. What the Science Supports
| Period | Climate | Subsistence | Civilization Evidence |
|---|---|---|---|
| LGM (~20,000 BCE) | Cold, dry, unstable | Nomadic foraging | None |
| Terminal Pleistocene (14,000–11,700 BCE) | Warming with volatility | Epipaleolithic foraging | Semi-sedentary camps |
| Holocene (from 11,700 BCE) | Warm, stable | Farming begins | First villages and complex societies |
| Post-4000 BCE | Optimal climate | Urbanism, writing | Bronze Age civilizations emerge |
✅ Conclusion
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Yes, the Ice Age climate was far too volatile for agriculture or urban complexity.
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The development of farming depended on the relatively rare conditions of climate stability provided by the Holocene.
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This is a serious and well-supported counterargument to Hancock-style lost civilization claims, which rely on anachronistic assumptions about technological and social development during a time when the biosphere was barely habitable in many places.
Would you like charts showing climate fluctuations during the Ice Age, or a map of the known early agricultural zones?
Dansgaard-Oeschger (D-O) events and Heinrich events are two types of rapid climate fluctuations that occurred during the last Ice Age. They are well-documented in ice cores and marine sediments and are critical for understanding why the Ice Age climate was too unstable for early agriculture or civilizations to develop.
Here’s a breakdown of both:
🌡️ 1. Dansgaard-Oeschger (D-O) Events
📌 What They Are:
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Abrupt warming events in the Northern Hemisphere during the last glacial period.
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First identified in Greenland ice cores by Willi Dansgaard and Hans Oeschger in the 1980s.
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Occurred roughly every 1,500 years (though not strictly periodic).
🔄 Pattern:
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Rapid warming of up to 8°C (14°F) in a few decades or less.
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Several centuries of warmth (interstadial period).
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Gradual cooling over ~1,000 years.
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Repeat cycle.
🔬 Evidence:
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Greenland ice cores (δ¹⁸O isotopes).
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Speleothems (cave deposits).
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North Atlantic marine sediment cores.
🧠 Importance:
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Suggests that climate could flip dramatically within a human lifetime.
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Challenged the old belief that climate change is always slow and gradual.
❄️ 2. Heinrich Events
📌 What They Are:
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Massive discharges of icebergs from the Laurentide Ice Sheet into the North Atlantic.
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Named after marine geologist Hartmut Heinrich.
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Occurred approximately 6–7 times during the last 70,000 years.
🔄 What Happens:
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Icebergs break off in huge numbers.
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They carry rocks and sediments (ice-rafted debris or IRD) far into the Atlantic.
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As they melt, they freshen the ocean surface, disrupting ocean circulation.
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This slows or halts the Atlantic Meridional Overturning Circulation (AMOC).
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Causes cooling in the North Atlantic, often followed by wider climate disruption.
🔬 Evidence:
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IRD layers in North Atlantic sediment cores.
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Drops in sea surface salinity and temperature.
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Linked to cold spikes in Greenland ice cores.
🌍 Effects:
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Regional cooling in Europe and North America.
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May have triggered or amplified D-O cycles.
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Possibly linked to mass megafauna deaths and human migration events.
🧩 How They Fit Together
| Feature | Dansgaard-Oeschger | Heinrich |
|---|---|---|
| Type | Rapid warming | Massive cooling |
| Trigger | Unknown (possibly ocean-atmosphere feedback) | Ice sheet instability |
| Duration | Decades to centuries | Thousands of years (sporadic) |
| Location | Primarily Northern Hemisphere | North Atlantic, with global effects |
| Evidence | Ice cores (Greenland), cave records | Marine sediments (IRD layers) |
🧬 Possible Interaction:
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Heinrich events often coincide with cold phases that interrupt or follow D-O events.
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Some scientists think Heinrich events may "reset" the climate system, after which a new D-O cycle begins.
🌾 Relevance to Early Human History
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These events created a climate that was:
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Unstable, swinging between cold and warm.
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Unpredictable, even over short timeframes.
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Unsuitable for agriculture, which needs decades of consistent seasons.
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This strongly undermines claims of advanced civilizations during the last Ice Age (as proposed by Graham Hancock), because any complex society would have had to survive repeated, catastrophic climate shocks.
Would you like visual graphs of D-O and Heinrich event timelines from the Greenland ice core record?
The period before the Last Ice Age is known as the Eemian Interglacial (roughly 130,000–115,000 years ago). It was a warm period, in many ways comparable to or even warmer than today. So the short answer is:
✅ Yes, it is theoretically possible that agriculture could have emerged then — but there is no evidence that it did, and several reasons to think it didn't.
🌍 Climate Before the Last Ice Age: The Eemian Interglacial
| Feature | Eemian Interglacial (~130,000–115,000 years ago) |
|---|---|
| 🌡️ Temperature | Global average temperatures were ~1–2°C warmer than today |
| 🌊 Sea Levels | ~6–9 meters higher than present (Greenland & Antarctica partially melted) |
| 🌿 Environment | Forests reached farther north; Sahara was greener |
| 🐘 Fauna | Megafauna (elephants, lions, rhinos) common in Europe |
| 🧍 Hominins | Neanderthals and early Homo sapiens in Eurasia and Africa |
So the Eemian was warm and ecologically rich, with climates and biomes favorable to long-term human habitation in many regions.
🤔 Could Civilization or Agriculture Have Arisen Then?
🌱 1. Theoretical Possibility
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Yes, the stable climate of the Eemian could have supported plant domestication, sedentary villages, and even early agriculture.
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Human groups may have experimented with intensive gathering, proto-farming, or land management (e.g. fire-stick farming).
🧪 2. But There's No Evidence
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Archaeological evidence shows that humans were still hunter-gatherers, using stone tools, with no signs of agriculture, animal domestication, or permanent settlements.
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No evidence of:
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Domesticated crops or animals
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Storage pits, granaries, or sedentary architecture
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Writing, metallurgy, or monumental architecture
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Early Homo sapiens were anatomically modern but behaviorally still foragers, with regional tool industries like the Middle Stone Age (Africa) or Mousterian (Europe).
🧬 3. Population and Cognitive Limits
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Human populations were small and dispersed.
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While Homo sapiens had modern anatomy, some researchers argue symbolic thinking and cumulative culture didn’t fully emerge until ~70,000–50,000 years ago (the "cognitive revolution").
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That said, this is debated—some signs of symbolic behavior (e.g. ochre use, shell beads) go back earlier.
🧊 What Happened After the Eemian?
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Around 115,000 years ago, Earth entered the Last Glacial Period, which lasted until ~11,700 BCE.
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This brought about:
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Massive ice sheets over Europe and North America
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Global temperature drops
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Sea level fall (~120 m)
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Increased climate volatility (D-O and Heinrich events)
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Any hypothetical progress toward sedentism or agriculture would have been cut off or reversed by this severe shift.
🧠 Why This Matters for "Lost Civilization" Theories
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The Eemian is the only pre-Holocene period in the last 400,000 years with a climate warm and stable enough to plausibly support agriculture.
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But:
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No material evidence for agriculture or complex society
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No genetic evidence of domesticated crops
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No known human population centers or large-scale habitation
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So:
❌ There is no known civilization or agricultural society from the Eemian period, despite its theoretical possibility.
🧬 Summary
| Period | Climate | Human Culture | Agriculture? | Civilization? |
|---|---|---|---|---|
| Eemian (130k–115k ya) | Warm, stable | Foraging (early Homo sapiens, Neanderthals) | ❌ No evidence | ❌ No evidence |
| Last Glacial Period (115k–11.7k ya) | Cold, unstable | Hunter-gatherers | ❌ Impossible | ❌ Impossible |
| Holocene (11.7k ya–present) | Warm, stable | Farming, then cities | ✅ Yes | ✅ Yes |
Would you like a visual timeline of interglacial periods and climate trends over the last 200,000 years?
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