Day: September 25, 2026

How Climate Shaped the Inca Empire — and Now Threatens Its Greatest Sites

Ollantaytambo (Quechua: Ullantaytampu) is both a living town and a major Inca archaeological site in Peru’s Sacred Valley, about 72 km (45 mi) by road northwest of Cusco, at an elevation of roughly 2,792 m (9,160 ft).

Inca stone masonry is renowned for its precision dry-stone (mortarless) construction, especially in elite and ceremonial buildings. Stones fit so tightly that a knife blade or piece of paper often cannot pass between them.

Inca (Inka) civilization and climate impacts encompass both historical influences on the empire’s rise and adaptations, and modern climate- change threats to surviving archaeological sites like Machu Picchu and Ollantaytambo.

A split image depicting Machu Picchu on the left with lush green terraces under a bright sky, and a dramatic mountain landscape on the right featuring snow-capped peaks and fog.
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Ollantaytambo (Quechua: Ullantaytampu) is both a living town and a major Inca archaeological site in Peru’s Sacred Valley, about 72 km (45 mi) by road northwest of Cusco, at an elevation of roughly 2,792 m (9,160 ft).

Inca history: In the mid-15th century, Emperor Pachacuti conquered the area, razed an earlier settlement, and developed it as a royal estate. He oversaw construction of the planned town, extensive agricultural terraces (andenes), irrigation systems, and a ceremonial complex. The site later became a stronghold for Manco Inca Yupanqui during the Spanish conquest. In 1537, Inca forces under Manco defeated a Spanish expedition led by Hernando Pizarro near Ollantaytambo (the Battle of Ollantaytambo) by using high terraces and flooding the plain, one of the few clear Inca military successes against the conquistadors. Manco later withdrew to Vilcabamba.

The archaeological site (“Temple Hill” / “Fortress”): The hillside complex features massive stone terraces (Pumatallis), the unfinished Temple of the Sun with its famous Wall of the Six Monoliths (large, precisely fitted rose rhyolite blocks), fountains, and other structures. Construction appears to have been interrupted (likely by the Spanish conquest or earlier internal conflicts), leaving unfinished walls and scattered “tired stones.” Nearby are storehouses (qullqas) on the hillsides and the Kachiqhata quarries across the river, connected by roads and ramps.

The town itself: It retains much of its original Inca orthogonal street grid and some of the oldest continuously occupied dwellings in South America. Canals and many buildings from the Inca period are still in everyday use.

Modern context: It is a popular tourist stop in the Sacred Valley, a common overnight base or departure point for trains to Machu Picchu and Aguas Calientes, and near the start of the classic Inca Trail trek. The surrounding terraces and landscape remain agriculturally productive.

The site combines urban planning, sophisticated stonework, agricultural engineering, and military history in one place, making it one of the most complete and accessible examples of Inca architecture still partly inhabited.

View of ancient stone walls at a historic site, featuring large, precisely cut stones and openings, surrounded by mountains and a sandy path.
Archaeological Site Ollantaytambo: Fortress – Tambo of the Incas

Inca stone masonry is renowned for its precision dry- stone (mortarless) construction, especially in elite and ceremonial buildings.

Most everyday structures used fieldstone, adobe, or roughly worked stone with mortar, but the finest work, seen at sites like Sacsayhuamán, Cusco’s Coricancha, Machu Picchu, and Ollantaytambo, employed highly skilled ashlar and polygonal techniques.

Archaeologist John H. Rowe and later classifications distinguish two primary fine styles, with subtypes:

  • Coursed (or sedimentary/ashlar) masonry: Rectangular or near- rectangular blocks laid in roughly horizontal courses. Preferred for the most sacred or elite structures (e.g., Coricancha). More unforgiving of errors, as broken corners cannot easily be reshaped.
  • Polygonal masonry: Irregularly shaped, multi-sided blocks that interlock like a jigsaw puzzle. Includes cellular (smaller stones) and cyclopean/ashlar polygonal (very large stones, as at Sacsayhuamán). Often features beveled edges that create shadow lines and slightly convex “pillowed” faces.

Walls frequently incline slightly inward, with rounded corners, enhancing stability.

The Incas lacked iron tools and the wheel for transport. They relied on:

Hammerstones: Hard river cobbles (often quartzite or similar) of varying sizes. Larger ones for roughing out, progressively smaller ones for finer pecking and dressing. Impact marks are visible on many unfinished or less-refined stones; waste chips appear in excavations. Jean- Pierre Protzen’s experiments at Ollantaytambo successfully replicated tight fits using only hammerstones.

Bronze or copper tools, stone wedges, and pry bars for splitting along natural fracture planes or rows of drilled/pecked holes.

Ropes of ichu grass, leather, or fiber for hauling and lifting; wooden levers and beams; earthen ramps.

Some researchers have proposed limited chemical etching (e.g., plant- based mixtures or mineral slurries) for edge smoothing, based on chronicles and folklore, but the primary method was mechanical pecking and grinding. Claims of widespread “stone softening” or unknown advanced technology lack strong archaeological support.

Construction Process

  1. Quarrying: Stones (andesite, granite, limestone, rhyolite, etc.) were extracted near sites when possible (e.g., Kachiqhata quarries near Ollantaytambo for the Temple Hill monoliths). Workers followed natural cracks or created them with wedges and hammering.
  2. Transport: Massive blocks (some at Sacsayhuamán estimated at 100 and more tons) were moved by large teams under the mit’a labor tax system, thousands of workers using thick ropes, rollers or log skids, and ramps. Spanish chroniclers describe this process; “tired stones” abandoned in transit remain visible at places like Ollantaytambo.
  3. Shaping and fitting: Stones were roughly shaped at the quarry, then refined on site. The key to tight joints was iterative trial- and- error:
    • A stone was placed against its neighbors.
    • High points were marked (sometimes with dust or by observation).
    • It was removed, pecked down with hammerstones, and tested again, repeatedly.
    • Protzen demonstrated that this produces precise, complex curved or multi- planar interfaces without templates or advanced measuring tools.
    • Lifting bosses (small protruding knobs left on the lower outer faces) allowed ropes or levers to position heavy blocks; many were later removed or left in place.
  4. Assembly: Dry-fitted. Joints are often tightest on the visible outer face, with slight gaps or packing farther in. Some walls incorporate natural bedrock outcrops, blending architecture with the landscape (caninacukpirca technique). Foundations were carefully prepared, often on bedrock for stability.

Unfinished sections and scattered blocks at sites like Ollantaytambo’s Temple Hill illustrate the process mid- stream, interrupted by the Spanish conquest or earlier events.

Inca walls excel in earthquake-prone regions. Interlocking polygonal shapes allow stones to shift slightly (“dance”) during shaking and resettle without collapse. Inward- leaning walls, rounded corners, absence of weak mortar planes, and integration with bedrock reduce stress concentrations and resonant frequencies. Modern observations and analyses confirm their resilience compared to many rigid mortared structures.

Precision work required enormous organized labor via the mit’a system and specialized master masons. Chroniclers report tens of thousands involved in major projects such as the rebuilding of Cusco or Sacsayhuamán under Pachacuti and his successors. Skills appear to have drawn partial inspiration from earlier Andean traditions (e.g., Tiwanaku), adapted and refined by the Incas.

In short, Inca masonry achieved its extraordinary precision through skilled observation, iterative hand- fitting with simple but effective stone tools, massive, coordinated labor, and deep practical knowledge of local materials and geology, rather than lost high technology. The results remain among the finest dry- stone achievements in world architecture.

Three children playing near a stone wall with a wooden door, one child washing something in a bowl, and another sitting on a rock.
An Incan doorway still used in the town. Ollantaytambo – Wikipedia

Inca (Inka) civilization and climate impacts encompass both historical influences on the empire’s rise and adaptations, and modern climate- change threats to surviving archaeological sites like Machu Picchu and Ollantaytambo.

Historical Climate Context and Inca Adaptations

Paleoclimate records (including lake sediments near Ollantaytambo at Marcacocha) show a shift toward warmer and relatively more favorable conditions in the Andes starting around AD 1100- 1150, following earlier arid phases.

This warming enabled expansion of agriculture to higher altitudes through extensive terracing (andenes), glacial- fed irrigation, and agroforestry.

These innovations supported increased crop productivity (maize, potatoes, quinoa, etc.) and helped fuel the rapid growth of the Inca Empire from the Cusco region in the 15th century.

The Incas were highly adaptive to Andean climate variability, including El Niño–Southern Oscillation (ENSO) effects (which can bring heavy rains/floods to the coast and droughts to the southern highlands) and frost risks at elevation:

  • Terraces and microclimates: Stepped agricultural terraces created warmer, more stable growing conditions, reduced erosion, and managed water. Sites like Moray experimented with different ecological zones.
  • Irrigation and water management: Sophisticated canals, reservoirs, and systems that captured glacial melt and rainfall.
  • Storage and resilience: Large qullqa storehouses for surplus food; freeze- drying techniques (e.g., chuño potatoes); diversified crops and vertical control of multiple ecological zones (“vertical archipelago”).
  • Landscape engineering integrated with natural topography for stability against landslides and seismic activity.

Climate was one enabling factor among many (social organization, military, labor systems like mit’a); it was not the sole driver of imperial expansion or later challenges. Spanish conquest, disease, and internal conflicts were decisive in the empire’s end, though climate stresses may have played secondary roles in earlier Andean societies.

Modern Climate Impacts on Inca Sites

Today, anthropogenic climate change poses growing risks to Inca archaeological sites in the Sacred Valley and beyond:

Increased extreme weather: Heavier rains, more intense El Niño events, and shifting precipitation patterns raise landslide, flooding, and erosion risks on steep slopes. Machu Picchu has experienced threats from heavy rains triggering slides and mudflows; glacial lake outburst floods (GLOFs) in the broader region (linked to rapid glacier retreat) have caused nearby disasters.

Erosion and structural threats: Intense rainfall and foot traffic accelerate wear on terraces, pathways, and stonework. Combined with seismic activity, this challenges the dry- stone masonry’s long- term integrity.

Biodiversity and ecosystem shifts: Changes in temperature and moisture affect the cloud- forest environment surrounding Machu Picchu, impacting vegetation that helps stabilize slopes.

Tourism and management pressures: High visitor numbers compound climate stresses through soil compaction and path erosion. Authorities have responded with timed- entry circuits, capacity limits, and conservation measures.

Sites like Machu Picchu (a UNESCO World Heritage Site) and Ollantaytambo face ongoing monitoring and adaptive management. Conservation efforts draw lessons from Inca techniques, such as terrace restoration and watershed management, while addressing modern threats through improved drainage, visitor controls, and research into resilient practices.

In summary, favorable climatic shifts and sophisticated environmental engineering helped the Incas thrive in a challenging mountain environment.

Today, accelerating climate change threatens the physical integrity of their monuments through intensified extremes, glacier loss, and erosion, underscoring the need for continued preservation informed by both ancient knowledge and modern science. Official site management and scientific monitoring continue to evolve in response.

Ancient terraced ruins of Moray in Peru, featuring layered agricultural platforms and surrounding landscape with cacti.
Archaeological Site Ollantaytambo: Fortress – Tambo of the Incas

Modern Andean Climate Data (focusing on the Peruvian Andes, including the Cusco- Sacred Valley- Machu Picchu region)

Temperature Trends

  • The tropical and central Andes have warmed significantly. Typical rates are 0.15- 0.25 °C per decade over recent decades (higher at elevations above 4,000 m).
  • In the Vilcanota- Urubamba basin (which includes the Sacred Valley and approaches to Machu Picchu), air temperature rose by approximately 0.018 °C per year (≈ 0.18 °C/decade) from 1980-2018.
  • National Peruvian data show the 2024 annual mean temperature reached a record high, about +1.18 °C above the long- term historical average.
  • High- elevation sites often warm faster than the global average (“elevation- dependent warming”).

Precipitation Patterns

  • Trends are more variable and spatially heterogeneous than temperature.
  • Some basins (e.g., parts of the Rio Santa / Cordillera Blanca) show modest increases; others, including parts of the southern Peruvian Andes, show mixed or weaker signals.
  • A clear shift toward more extreme events: projections indicate substantial increases in heavy precipitation days (very wet days) alongside intensified droughts due to higher evaporation.
  • Seasonal pattern remains strong: wet season roughly November- March/April; dry season May-September (classic for Cusco/Machu Picchu tourism).

Glacier Retreat (One of the Clearest Signals)Tropical Andean glaciers are among the fastest-retreating in the world:

  • Southern Peruvian Andes (Cordilleras Vilcanota, Vilcabamba, Urubamba): glacier area losses of 54-64% since the 1970s (to 2020).
  • Broader tropical Andes: roughly 40- 42% area loss between 1990 and 2020.
  • Peru overall: glacier surface area fell from ~2,349 km² in the early 1960s to ~1,049 km² by 2020 (≈ 55% loss); volume losses are comparable.
  • Ongoing mass- balance losses continue at high rates (negative geodetic balances of several tenths of a meter water equivalent per year in recent decades).

Future Projections (Late 21st Century)

Under high- emissions scenarios (e.g., RCP8.5 / SSP5- 8.5):

  • Temperature increases of roughly 3.5- 4.5 °C in key Peruvian Andean basins relative to late-20th/early- 21st- century baselines.
  • Precipitation totals may rise modestly (around 10-12% in some projections), but with much larger increases in extreme wet- day precipitation and greater drought intensity from higher evaporative demand.
  • Further dramatic reduction in solid precipitation (snow/ice) and continued rapid glacier loss, affecting dry- season water availability.

Key Implications for the Region

Rising temperatures, glacier melt, and more extreme rainfall and drought cycles increase risks of landslides, flooding, erosion of agricultural terraces and archaeological sites, and seasonal water stress, directly relevant to the Sacred Valley, Ollantaytambo, and Machu Picchu.

Sources include peer- reviewed studies using station data, reanalysis, satellite observations, and climate models (e.g., work on Vilcanota- Urubamba and Rio Santa basins, tropical Andean glacier inventories, and SENAMHI/Peruvian national assessments). Data continue to be updated; the strongest, most consistent signal remains the rapid warming and glacier decline.

View of terraced ruins of ancient Incan structures surrounded by mountains under a blue sky.
Archaeological Site Ollantaytambo: Fortress – Tambo of the Incas

Guardian: The “Planetary Guardians” Warn our Global Life Support Boundaries have been Breached

The climate movement just got weirder.

Back in reality the world is flourishing, with greening deserts and soaring crop yields.

I only have one message for the Planetary Guardians. I refuse to take the Planetary Guardians seriously unless they can produce authentic accreditation from the United Federation of Planets.

Illustration of the 'Planetary Guardians' cartoon character group, displaying alarm over breached environmental boundaries. The scene includes a globe labeled 'Earth,' various charts, and characters in superhero outfits. Background features a picturesque landscape with people enjoying nature, emphasizing environmental concerns and humor.

From Watts Up With That?

Essay by Eric Worrall

The climate movement just got weirder.

‘Planetary boundaries’ necessary for flourishing of life have been massively breached, scientists warn

New report shows key indicators of Earth’s health are ‘outside the safe operating space’ as climate disaster looms

The planetary life support systems relied upon by humans have deteriorated to their worst levels ever recorded amid ongoing pollution and habitat destruction, according to a key yet grim annual update by scientists.

Of the nine “planetary boundaries” that help determine whether life can flourish on Earth, seven are being breached at their highest ever levels of transgression, according to the latest planetary health check, a process that was established in 2009.

The seven key indicators in the danger zone include climate change, change in biosphere integrity, land system change, freshwater change, modification of biogeochemical flows, introduction of novel entities and, for the first time last year, ocean acidification.

…

“The diagnosis is unambiguous – pressure is rising across every planetary boundary already outside the safe operating space,” said Boris Sakschewski, lead author of the report. “It means that the risk of large-scale, persistent and potentially irreversible change is increasing, while our margin for error in tackling these problems is shrinking.”

…

“These are not separate emergencies; the planet is telling us, in every region at once, that it is out of balance,” said Hindou Oumarou Ibrahim, chair of Planetary Guardians, a coalition of scientists, business leaders and activists.

…Read more: https://www.theguardian.com/environment/2026/sep/21/planetary-boundaries-breached-scientists-warn-climate-crisis

Back in reality the world is flourishing, with greening deserts and soaring crop yields.

I’m struggling to get past the “Planetary Guardians” reference. Could you imagine introducing yourself to someone as a member of the “Planetary Guardians” with a straight face?

Are they required at all times to carry a spandex suit with underwear on the outside? Or is it more of a Men in Green thing? Dark sunglasses, very dark green suits, and serious expressions?

Just imagine – there was a time voters took these people seriously.

I only have one message for the Planetary Guardians. I refuse to take the Planetary Guardians seriously unless they can produce authentic accreditation from the United Federation of Planets.

Live long and prosper.

How a 4,200-Year-Old Megadrought Helped Create the Babylonian Empire

The Old Babylonian Empire (also called the First Babylonian Empire or First Dynasty of Babylon) lasted roughly from c. 1894 to 1595 BC (middle chronology). It was a major Bronze Age power in Mesopotamia centered on the city of Babylon, which rose from a minor city- state to dominate much of southern Mesopotamia and beyond under its most famous ruler, Hammurabi.

The 4.2- kiloyear event (also called the 4.2 ka BP event or Bond event 3) was a major aridification and cooling episode centered around 2200 BC (roughly 4,200 years before present).

A majestic ancient city with a pyramid-like structure in the background, set against a dramatic sky. In the foreground, a figure in ornate clothing gazes over a river, while a caravan of people and animals traverses a dry landscape.
AI generated by Grok

The Old Babylonian Empire (also called the First Babylonian Empire or First Dynasty of Babylon) lasted roughly from c. 1894 to 1595 BC (middle chronology). It was a major Bronze Age power in Mesopotamia centered on the city of Babylon, which rose from a minor city- state to dominate much of southern Mesopotamia and beyond under its most famous ruler, Hammurabi.

Background and Rise

After the collapse of the Sumerian Third Dynasty of Ur (Ur III) around 2004 BC and the subsequent Isin-Larsa period of competing city- states, Amorite (West Semitic “westerner”) groups gained control of various centers, including Babylon. Sumu- abum (c. 1894- 1881 BC), an Amorite, is traditionally listed as the first king of the dynasty; he and his early successors expanded local control over nearby towns such as Dilbat, Kish, Sippar, and Borsippa.

Babylon remained relatively modest until the reign of its sixth king, Hammurabi (c. 1792- 1750 BC). Through a mix of diplomacy, shifting alliances, and decisive military campaigns, he conquered key rivals (including Larsa under Rim- Sin, Eshnunna, Mari, and others), uniting most of southern Mesopotamia.

At its height, the empire stretched across the alluvial plain of the Tigris and Euphrates (the region thereafter often called Babylonia), extending influence northward toward Assyria and westward toward Mari and beyond. The southern half of Mesopotamia became known as Babylonia, with Babylon as its political, cultural, and religious center; the god Marduk rose in prominence as the empire’s chief deity.

Key Achievements

Code of Hammurabi: The best- known legacy is the collection of laws (roughly 282 provisions) inscribed on a large diorite stele (now in the Louvre). It covers economic matters, family law, crime, property, and more, often applying the principle of lex talionis (“an eye for an eye”) with penalties scaled by social status. It is one of the most complete and famous early legal texts from the ancient Near East, though earlier Sumerian law collections existed.

Administration, irrigation, temple building, and infrastructure improvements helped consolidate control.

Cultural developments included the flourishing of the Old Babylonian dialect of Akkadian (which became a reference form of the language), continued use of Sumerian for literary and religious purposes, and advances in literature, scholarship, and architecture.

Languages included Akkadian (official and administrative), Sumerian (literary and religious), and Amorite elements. Religion was the traditional Mesopotamian pantheon centered increasingly on Marduk.

Decline and End

After Hammurabi’s death, his successors (notably Samsu- iluna) struggled to hold the expanded territories; southern regions and other areas broke away or faced pressure. The dynasty continued for about another 150- 200 years under declining power. It ended around 1595 BC when a Hittite raid under Mursili I sacked Babylon. This created an opening for the Kassites (from the east) to take control, ushering in the Kassite (or Middle Babylonian) period.

Legacy

The Old Babylonian period made Babylon the enduring heart of southern Mesopotamia. Hammurabi’s code and the elevation of Babylon and Marduk had long- term cultural and political influence. The empire is distinct from the much later Neo- Babylonian (Chaldean) Empire of the 7th-6th centuries BC (Nebuchadnezzar II and others).

Chronology relies on the “middle chronology” commonly used by scholars; absolute dates can shift slightly depending on the system. Primary sources include royal inscriptions, administrative documents, letters (especially the rich Mari archives), and the law code stele itself.

A replica of the Ishtar Gate, featuring blue walls decorated with painted animals and golden accents, surrounded by greenery.
Replica of the Ishtar Gate Babylon – Wikipedia

The Old Babylonian Empire (c. 1894- 1595 BC, peaking under Hammurabi c. 1792- 1750 BC) developed in the aftermath of major climate stress and operated under generally warmer, drier conditions than today in southern Mesopotamia, with ongoing challenges from reduced water availability and soil salinization.

Climate was one contributing factor among political, social, and economic ones; it influenced migrations, agriculture, and resilience but did not solely determine the empire’s rise or fall.

Preceding Climate Crisis: The 4.2 ka Event

A significant aridification event around 2200- 1900 BC (the “4.2 ka event” or Bond event 3) affected the Near East. Proxy records (marine sediments from the Gulf of Oman showing increased Mesopotamian dust, speleothems, corals indicating prolonged winter dust storms, shamals and climate models) point to reduced precipitation (potentially 30% in some areas), lower Tigris- Euphrates River flows (a Holocene low around 2000 BC), cooler conditions in some phases, and increased aridity and dust.

This coincided with the collapse of the Akkadian Empire and pressures on the subsequent Ur III dynasty. Northern rain- fed agriculture was especially hard- hit, prompting population movements (including Amorite groups) southward into the irrigated alluvial plains. A brief wetter interval may have occurred during parts of Ur III, but overall conditions trended drier into the early second millennium BC. These disruptions helped create the fragmented Isin- Larsa landscape from which Babylon rose.

Climate During the Old Babylonian Period

Climate models of the Tigris- Euphrates basin indicate precipitation reached a minimum near 2000 BC, followed by a recovery and increase (roughly 14% in one simulation) toward 1750 BC. Textual and proxy interpretations suggest the interval ~1800- 1650 BC was warmer and drier than the modern climate, with harvests beginning 10- 20 days earlier. Conditions may have dried further around 1600- 1500 BC.

Southern Mesopotamia (the core of the empire) relied primarily on irrigation rather than rainfall. This provided greater resilience to rainfall declines than the north, but it created vulnerabilities:

  • Reduced river discharge limited water for canals.
  • Intensive irrigation in an arid setting raised water tables and caused progressive soil salinization (salts accumulating via evaporation and capillary action). This problem had begun earlier (late Sumerian and early Akkadian times) and continued; wheat yields declined and cultivation shifted heavily toward more salt- tolerant barley. By later periods, wheat was largely abandoned in some areas.

Hammurabi’s administration invested heavily in canal digging, maintenance, and water management, reflecting both expansion needs and adaptation to water scarcity. Agricultural productivity supported urban centers and the state, but salinization and variable floods remained long- term constraints.

Impacts on the Empire

Rise and resilience: Climate- driven migrations of Amorites contributed to the demographic and political shifts that enabled Babylon’s ascent. Centralized irrigation infrastructure and administration under Hammurabi helped buffer southern agriculture against the drier conditions that had destabilized the north.

Stresses: Salinization reduced long- term land productivity. Warmer and drier conditions increased the risk of crop shortfalls in drought years. Later drying around the mid- second millennium BC aligned with political fragmentation after Hammurabi, the Hittite sack of Babylon (c. 1595 BC), and the transition to Kassite rule, though military and internal factors were also decisive.

Broader context: Climate influenced settlement patterns, nomadic pressures, and economic strategies across the region, but societies adapted through technology (canals), crop choices, and political organization. Deterministic “climate collapse” models oversimplify; resilience and human agency were significant.

Evidence comes from paleoclimate proxies (sediments, corals, speleothems, models), archaeological settlement data, and cuneiform references to water works, yields, and occasional famines.

Absolute dating and regional variability introduce uncertainties, and the 4.2 ka event itself remains debated in its exact severity and global coherence.

Overall, the Old Babylonian Empire illustrates both vulnerability to aridification in a semi- arid riverine environment and successful adaptation via irrigation and state institutions.

A digital rendering of an ancient Mesopotamian cityscape featuring large stone structures, ziggurats, and lush gardens with palm trees under a blue sky.
Babylon: The Famous Ancient City

The 4.2- kiloyear event (also called the 4.2 ka BP event or Bond event 3) was a major aridification and cooling episode centered around 2200 BC (roughly 4,200 years before present).

It is widely linked to societal disruptions across the Near East and beyond, but its direct connection to the Old Babylonian Empire (c. 1894-1595 BC) is indirect: the event primarily destabilized earlier states and helped create the political and demographic conditions that enabled Babylon’s rise.

Timing and Nature of the Event

The event is generally dated to beginning around 2200 BC and lasting through much of the 22nd century BC, with some high-resolution records (e.g., Iranian speleothems) placing a major arid phase from about 4.26 to 3.97 ka BP (roughly 2260-1970 BC).

It involved reduced precipitation (estimates of 30- 50% declines in parts of the region), increased dust storms (shamals), lower river flows in the Tigris- Euphrates system, and cooler conditions in some areas. Proxy evidence includes dust layers in Gulf of Oman sediments, soil changes at sites like Tell Leilan in northern Mesopotamia, coral records from Oman showing prolonged winter dust seasons, and speleothem data.

It marks the formal start of the Meghalayan stage of the Holocene in the geological timescale and is associated with collapses or major transformations in multiple regions, including the Akkadian Empire in Mesopotamia, the Egyptian Old Kingdom, and aspects of the Indus Valley civilization.

Impact on Mesopotamia and Path to the Old Babylonian Empire

In Mesopotamia, the event strongly affected the Akkadian Empire (which had expanded into northern rain-fed zones). Northern settlements experienced widespread abandonment due to failed dry- farming agriculture. Populations migrated southward toward the more resilient irrigated alluvial plains of southern Mesopotamia. Contemporary texts refer to a “Repeller of the Amorites” wall built to manage or block these movements of western/Amorite pastoralist groups.

This contributed to the Akkadian collapse (around 2150 BC or slightly earlier), followed by the short Gutian interregnum and the rise and eventual fall of the Third Dynasty of Ur (Ur III, c. 2112- 2004 BC). A brief wetter interval may have occurred during parts of Ur III, but overall arid conditions persisted into the early second millennium BC. The resulting political fragmentation (the Isin-Larsa period) featured competing Amorite- led city- states.

The First Dynasty of Babylon (Old Babylonian Empire) emerged from this landscape. Its founder Sumu-abum (c. 1894 BC) and successors were of Amorite origin, the same groups whose southward movements were accelerated by the drought’s effects on northern and western pastoral zones. Within a few generations of the event’s peak impacts, Amorite rulers consolidated power in Babylon.

The empire’s later expansion under Hammurabi (c. 1792- 1750 BC) occurred after the most severe phase of the 4.2 ka aridification, during a period of relative recovery or adaptation in the south, supported by intensive irrigation systems.

Southern Mesopotamia’s reliance on river irrigation (rather than rain- fed farming) provided greater resilience than the north, though long- term issues such as soil salinization from irrigation in arid conditions continued.

Scholarly Context and Caveats

Many researchers (notably Harvey Weiss and collaborators) argue the megadrought was a key driver of northern abandonment, refugee flows, and imperial collapse. Others emphasize multi- causal explanations, including over- extension of the Akkadian state, internal politics, invasions (e.g., Gutians), and pre- existing environmental stresses, and note that some isotopic or settlement data show continuity or less dramatic subsistence shifts than a total “megadrought collapse” model implies. The event’s global coherence and exact magnitude remain debated, with regional variability.

In short, the 4.2 kiloyear event did not strike during the height of the Old Babylonian Empire. Instead, it reshaped the preceding political order through drought, migration, and collapse, paving the way for Amorite dynasties, including the one that made Babylon the center of a new Mesopotamian power.

Brainwashed by fear: How to save two generations lost to climate panic

For more than four decades, Americans have been subjected to a relentless drumbeat of environmental doom. They have been terrified by warnings of acid rain, the ozone hole, melting ice caps, drowned coastal cities, superstorms and mass extinctions. Then came Al Gore and increasingly apocalyptic warnings about global warming, which has since been rebranded as “climate change.”

Paul Ehrlich’s 1968 bestseller, “The Population Bomb,” promised mass starvation in the 1970s. Instead, Norman Borlaug’s Green Revolution fed a billion more people. Being wrong has never slowed down the doomsayers.

A colorful illustration contrasting a fear-driven climate panic industry with a diverse group of individuals engaging in a constructive discussion about climate solutions, emphasizing the importance of facts, collaboration, and a hopeful future.

From CFACT

By Frank Lasee

For more than four decades, Americans have been subjected to a relentless drumbeat of environmental doom. They have been terrified by warnings of acid rain, the ozone hole, melting ice caps, drowned coastal cities, superstorms and mass extinctions. Then came Al Gore and increasingly apocalyptic warnings about global warming, which has since been rebranded as “climate change.”

Today, we can see the consequences. Two generations of young people have been taught not to respect the environment, but rather to fear the future.

The numbers are disturbing. A Lancet Planetary Health survey of 15,793 Americans ages 16 to 25 found that 85 percent were at least moderately worried about climate change, including 58 percent who were very or extremely worried. More than half said climate change made them hesitant to have children.

Other research points the same way. A review of multiple studies found that stronger climate worry lines up with wanting fewer children or none at all.

Think about that. We have convinced millions of young people that the future is so bleak that they should reconsider having children.

Yet the picture of a dying planet bears little resemblance to the measurable world around us.

The Earth is getting greener. NASA reported that 25 to 50 percent of the world’s vegetated land greened significantly between 1982 and 2015 — an increase in leaf area roughly twice the size of the continental U.S. Researchers attributed about 70 percent of that greening to rising carbon dioxide.

So carbon dioxide is not merely an emission — it is plant food.

Agriculture tells the same story. The world now grows nearly three times as much grain on the same acre as it did in 1961. The cropland saved is close to the area of the U.S. and India combined. Credit better seeds, machinery, irrigation, modern farming, fossil fuel-derived fertilizer, and that carbon dioxide boost.

Our air is cleaner, too. EPA reports that emissions of the six main air pollutants fell 79 percent between 1970 and 2024, even as the economy grew 338 percent, Americans drove 195 percent more miles, and the population grew by two-thirds.

Prosperity has surged as well. The number of people living in extreme poverty worldwide fell from roughly 2.3 billion in 1990 to about 800 million today, even as the world population grew by nearly three billion. Life expectancy, literacy, and living standards are at record highs.

We have heard the doom and gloom predictions before. Paul Ehrlich’s 1968 bestseller, “The Population Bomb,” promised mass starvation in the 1970s. Instead, Norman Borlaug’s Green Revolution fed a billion more people. Being wrong has never slowed down the doomsayers.

None of this means environmental problems are imaginary. It means they are problems to solve and not reasons to surrender.

Previous generations built dams, cured diseases, split the atom, crossed oceans, and landed men on the Moon. They faced world wars, depressions, and nuclear standoffs, real existential dangers. Their answer was not to stop having children. It was to build a better world for them.

Even Elon Musk, who believes strongly that man-made carbon dioxide threatens the climate, preaches innovation and expansion — not retreat and despair. That is the mindset young people need.

So teach the real problems we can do something about — not false climate doom. Teach the triumphs, not just the panic. Teach how human ingenuity cleaned our air and rivers, tripled crop yields, cut extreme poverty by two-thirds, and greened a massive share of the planet.

Parents, this one is on us. Ask your school district what your children are being taught about climate, and what they are not. Ask to see the curriculum. Ask whether a single one of these numbers appears in it. Then say so out loud at the next school board meeting.

Two generations have been taught to fear the future. Let’s teach the next one to build it.

This article originally appeared at The Hill

AMOC Collapse Would Be Catastrophic: And Ice- Age Records Show It’s Happened Before

Yeah, a full collapse of the Atlantic Meridional Overturning Circulation (AMOC) would produce severe, far- reaching climate disruptions that scientists widely describe as catastrophic for large regions, especially northwestern Europe, the U.S. East Coast, and monsoon-dependent areas in Africa, Asia, and South America.

The AMOC has switched states in the past, that is well- supported by paleoclimate records.

During the last glacial period (roughly 115,000- 11,700 years ago), the climate system exhibited repeated abrupt shifts closely linked to changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC). The two most prominent examples are Dansgaard-Oeschger (D-O) events and Heinrich events.

Illustration depicting the potential catastrophic collapse of the AMOC, with visual elements like ice, oceans, and geographic outlines showing past ice-age records.
AI generated by Grok

Yeah, a full collapse of the Atlantic Meridional Overturning Circulation (AMOC) would produce severe, far- reaching climate disruptions that scientists widely describe as catastrophic for large regions, especially northwestern Europe, the U.S. East Coast, and monsoon-dependent areas in Africa, Asia, and South America.

The AMOC is a major system of ocean currents (part of the broader thermohaline “conveyor belt”) that transports enormous amounts of heat northward in the Atlantic, on the order of 1 petawatt, far exceeding total human energy use. It helps keep northwestern Europe milder than other regions at similar latitudes. A collapse (or very strong weakening into a near-shutdown state) would sharply reduce this heat transport.

Main projected impacts

Cooling and weather extremes in Europe: Models show rapid cooling of several degrees to 5- 15°C (or locally more) in northwestern Europe over decades, with particularly harsh winters. Sea ice could expand southward (in some simulations toward the UK or Netherlands coasts). Summers might remain relatively warm due to ongoing greenhouse forcing, but year-round drier conditions, intensified droughts (especially in southern Europe), stronger winter storms, and wild temperature swings would severely damage agriculture, for example, one estimate reduces UK arable land from ~32% to ~7%.

Sea- level rise along the U.S. East Coast: Dynamic effects from the circulation change would add tens of centimeters to over half a meter (or more in places) of regional sea- level rise on top of global thermal expansion and ice melt, increasing coastal flooding risk.

Tropical and monsoon disruptions: A southward shift of the Intertropical Convergence Zone (ITCZ) would reduce rainfall in West Africa (potentially ~30%) and parts of India (~20%), disrupt Amazon seasonality (dry and wet seasons flipping in some models), and alter precipitation across other tropical regions. This threatens food systems for hundreds of millions of people.

Broader effects: Changes in storm tracks, marine ecosystems and fisheries (via altered nutrient upwelling and temperatures), Arctic sea- ice expansion, possible modest additional atmospheric CO₂ release from ocean carbon changes (with small net global warming after regional cooling offsets), and potential cascading stresses on other systems. Northern Hemisphere cooling would contrast with some Southern Hemisphere warming (a bipolar seesaw pattern seen in paleoclimate records).

These changes would unfold over decades to about a century once a tipping threshold is crossed, abrupt on human and societal timescales, though not instantaneous. Paleoclimate evidence (e.g., Dansgaard-Oeschger and Heinrich events) shows the AMOC has switched states in the past with major global repercussions, including large shifts in tropical rainfall.

Likelihood and uncertainty

A full collapse is not certain this century.

The IPCC AR6 assessed medium confidence that an abrupt collapse would not occur before 2100, while projecting overall weakening.

More recent studies are mixed: some identify early- warning signals (increasing variance/autocorrelation, freshwater- transport indicators, or “cold blob” patterns) suggesting the system is losing stability and could approach a tipping point this century under continued high emissions; constrained model ensembles project stronger weakening (~40- 50% by 2100 in some analyses) than the multi- model mean; other work finds resilience due to Southern Ocean upwelling, with collapse unlikely this century or reversible if forcing is reduced.

The risk is commonly framed as low- to-medium probability but very high impact. Weakening is already observed or inferred in various datasets, and continued high greenhouse- gas emissions plus Greenland meltwater increase the chance of further decline or eventual tipping. Reducing emissions lowers the risk.

In short, the statement is consistent with the scientific literature: a collapse would not freeze the planet as in fiction, but it would impose abrupt, multi- decadal regional climate shifts severe enough to strain agriculture, infrastructure, ecosystems, and societies across the North Atlantic sector and beyond. Monitoring improved early- warning systems, and mitigation remain the practical responses.

Map depicting ocean currents in the North Atlantic region, including the East Greenland Current, Polar Front, and North Atlantic Current, with Iceland and surrounding areas marked.
Arctic freshwater forcing of the Younger Dryas cold reversal | Nature

The AMOC has switched states in the past, that is well- supported by paleoclimate records.

During the last glacial period (roughly 115,000- 11,700 years ago), the climate system exhibited repeated abrupt shifts closely linked to changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC). The two most prominent examples are Dansgaard- Oeschger (D- O) events and Heinrich events.

Dansgaard- Oeschger events

These were rapid warmings recorded in Greenland ice cores, with temperature increases of about 5-16°C occurring over decades (sometimes as little as a decade), followed by more gradual cooling over centuries. They occurred repeatedly during marine isotope stages 2- 4 under intermediate glacial conditions.

Proxy evidence (including Pa/Th ratios and benthic δ¹³C in ocean sediments, plus ice- core isotopes) indicates that the warm phases (interstadials) corresponded to a relatively strong AMOC, with active deep-water formation in the Nordic Seas, while the cold phases (stadials) featured a weaker AMOC.

The shifts involved reorganization of atmospheric circulation, including northward movements of the Intertropical Convergence Zone (ITCZ) and associated rainfall belts during the warmings. Global effects appear in speleothem records (e.g., Asian and South American monsoons), European fluvial systems, and other archives, though the amplitude of change generally decreases with distance from the North Atlantic.

Heinrich events

These involved massive discharges of icebergs (primarily from the Laurentide Ice Sheet) into the North Atlantic, marked by distinct layers of ice- rafted debris (IRD) in sediment cores. They typically occurred during some of the longer, colder stadials that preceded certain D- O warmings.

The large freshwater input from melting icebergs is widely interpreted as having caused strong weakening or near- collapse of the AMOC by reducing surface density and suppressing deep convection. Consequences included:

  • Pronounced cooling across the North Atlantic and adjacent continents.
  • A bipolar “seesaw” pattern, with gradual warming in the Southern Hemisphere (visible in Antarctic ice cores).
  • Southward displacement of the ITCZ and rainfall belts, producing severe droughts or major hydroclimate anomalies across large parts of the northern tropics and subtropics (including Afro- Asian monsoon regions), while some southern tropical areas became wetter.

These tropical rainfall shifts are documented in a wide range of continental and marine proxies and occurred close in time (within dating uncertainties of hundreds of years) to the North Atlantic IRD layers. Similar AMOC reductions and associated climate impacts are also inferred for events such as Heinrich Stadial 1 and the Younger Dryas during the last deglaciation.

Overall significance

Together, these records demonstrate that the AMOC has existed in multiple states and can transition relatively rapidly between them, producing large regional- to- global climate repercussions, especially in heat transport, sea ice, and the position of tropical rain belts.

The glacial boundary conditions (large ice sheets, lower CO₂, different freshwater budgets) differ from today, so the exact thresholds and rates are not identical to modern projections. Nonetheless, the paleoclimate evidence establishes that AMOC state changes are a real mechanism capable of driving abrupt, widespread climate shifts, including major alterations in tropical rainfall patterns that affected monsoon systems on which large human populations now depend.

This past behavior is one reason climate scientists treat potential future AMOC weakening or collapse as a high- impact risk, even while the precise likelihood and timing under current anthropogenic forcing remain subjects of active research.

The Great Recycling Swindle

There is no such thing as a free lunch, as Milton Friedman never tired of pointing out. A local authority that pretends otherwise is not practising environmental stewardship.

It is practising virtue signalling at other people’s expense. Let’s take the £720 first.

It is not a recycling saving at all. It is a Love Food Hate Waste talking point about buying less food in the first place, describing what the average family could save by throwing away less edible food. That is a saving from wasting less, not from recycling more.

A cartoon illustration of a recycling industrial complex with various characters discussing waste management and taxes. One character looks worried while holding a council tax bill, and another, a cheerful official, promotes a free food waste caddy. The image features a variety of elements, including food waste, financial elements, and slogans like 'Nothing is free—the bill just moves somewhere else.'

From Tilak`s Substack

By Tilak Doshi

On Thursday I found a parcel waiting at the front door of my Wandsworth flat: a ‘free’ food waste caddy, a starter roll of compostable liners and a note from the council that deserves a place in the annals of municipal self-congratulation. Recycling my food waste, it explained, could save me “as much as £720 every year”. My leftovers would become “a sustainable power source and liquid fertiliser”. And because it is “much cheaper” for the council to recycle scraps than to bin them with the rubbish, the whole exercise “helps keep your Council Tax low”. Each of these claims turns out to be false, an evasion or a subsidy in disguise.

There is no such thing as a free lunch, as Milton Friedman never tired of pointing out. A local authority that pretends otherwise is not practising environmental stewardship. It is practising virtue signalling at other people’s expense. Let’s take the £720 first. It is not a recycling saving at all. It is a Love Food Hate Waste talking point about buying less food in the first place, describing what the average family could save by throwing away less edible food. That is a saving from wasting less, not from recycling more. WRAP, the climate NGO behind the campaign, now puts the annual cost of edible food binned by a family of four at £1,000. But the money is lost by typical household behaviour, not because food waste remains uncollected by the local council.

Separately collected food waste can indeed go to anaerobic digestion, which produces biogas and a digestate fertiliser. But biomethane from digestion is also eligible for the Government’s Green Gas Support Scheme, a tariff subsidy. A “sustainable power source” propped up by a tariff is not a free lunch; it is merely moved from domestic bills to general taxpayers. The household is thus drafted as an unpaid recycler, subject to the good Wandsworth council members that claim to be saving its constituents their own money.

Nor, to be fair to the council’s worthies, is the caddy entirely their idea. Wandsworth’s own website states that all households in the borough must have weekly food waste collections from March 31st 2026, a duty that traces to the Environment Act 2021. This was passed under a Conservative government and is now being delivered under the label of Simpler Recycling. Whitehall wrote the script; Wandsworth Council merely turned up in appropriate costume and supplied the marketing angle.

Social costs and benefits

Had anyone on the Wandsworth Waste Project Team taken the trouble to have a cursory acquaintance of the available analysis, they would have found a remarkably consistent verdict. Thomas Kinnaman of Bucknell University, having reviewed two decades of American recycling experience in the Journal of Economic Perspectives, argued for replacing several state recycling mandates with a moderate landfill tax. A study of a random national sample of municipalities by Robert Bohm, Kinnaman and two co-authors found that both average and marginal costs of recycling exceed those of simple collection and disposal at a landfill. Daniel Benjamin of the Property and Environment Research Center calculated that, even after crediting the resale of recovered materials, curb side programmes in 2009 cost on average $199 a ton against $119 for landfill and concluded that mandatory programmes leave society worse off. It argues that U.S. municipal curb side recycling programmes waste resources and probably do little, if anything, to benefit the environment.

In an article entitled ‘Recycling Is Garbage’ in 1996, New York Times journalist John Tierney concluded that mandatory recycling did not make economic or environmental sense. It legendarily provoked the most hate mail ever delivered to the Times. He returned in 2015 to report that it was still typically more expensive to recycle household waste than to landfill it. He likened the zeal of the faithful to a penance for the sin of affluence.

Food waste, Wandsworth Council’s new enthusiasm, fares worse still. A 2025 study by Jackson Somers of the University of Connecticut, published in the Journal of Environmental Economics and Management, found that a curb side organics collection programme cost per household was nine times the social benefit of the avoided methane. Across the United States, the median expansion would cost $478 per tonne of CO2-equivalent avoided, against an assumed social cost of carbon of $51. It should be noted here that the concept of the social cost of carbon itself is highly disputed, and it could well be negative if the greening benefits of higher atmospheric concentrations of carbon dioxide are fully taken into account.

Wandsworth’s operation is far from frugal: the council has explained that separate vehicles now collect rubbish, recycling, food waste and small electricals, each at its own time. One more fleet, one more caddy, one more cost on the beleaguered taxpayer. None of this is an argument against recycling as such. Recycled aluminium needs about 95% less energy than metal smelted from bauxite, so scrap commands a price, and a price is all a collector needs. Nobody requires a council leaflet to persuade a scrap dealer to fetch a can. Even Defra concedes that for some plastics the value on secondary markets does not outweigh the cost of collection. Free markets sort winners from losers objectively; policy mandates, however dressed up as virtuous signals, are a net cost to the taxpayer.

The Government’s own arithmetic

The council’s claim that food waste recycling keeps Council Tax low collides with Whitehall’s own paperwork. Defra’s final impact assessment in December 2024 for “Simpler Recycling” models the preferred option with English councils bearing £722 million in transition costs and £567 million in higher ongoing costs in present-value terms. The headline saving to councils of £188 million appears only after crediting about £1 billion of additional garden-waste charges on households and £474 million of deposit-return savings. Remove those and the ratepayer is left holding the caddy.

The department’s £5.9 billion “net benefit to society” for the whole package tells a similar tale. It rests on £10.5 billion of “carbon savings”; remove that single line and the package is some £4.5 billion in the red. The Defra claim rests entirely on how carbon is valued. Everything else in the model (collection costs, transition costs, sorting and the rest) nets out negative once the carbon credit is removed. Defra conveniently chose a carbon price that makes the sum positive. The UK values carbon by the marginal abatement cost, meaning the cost of cutting a tonne needed to hit legally binding carbon budgets. The circularity of Defra carbon accounting, driven by Net Zero ideologues, is astounding.

Household time, meanwhile, is treated as a rounding error: familiarisation and inconvenience costs to householders are not accounted for because Defra does not expect them to be significant. The time value of the person rinsing the caddy is evidently free. Tellingly, the same document abandons the plan for free garden-waste collections because the cost was disproportionate to the “carbon benefits”.

And the “free” in “free caddy” rests on the Government’s promise to fund councils’ net additional costs, the so-called new burdens doctrine. The Wandsworth Council leaflet says food waste recycling “helps keep your Council Tax low”. But council tax may well stay low locally only because the Treasury is covering the extra cost, not because recycling is cheap. So the cost of the new service has merely moved from the council’s books to the national taxpayer.

Milton Friedman’s dictum that there is no such thing as a free lunch has apparently not reached Wandsworth; one does not expect a copy of Free To Choose (1980) in the council library. But the deeper problem is the familiar mixture of luxury beliefs and other people’s money. Economists call the satisfaction of doing good a warm glow, and it is a preference, not a resource saving. When a state compels the ‘environmental’ ritual and raises the tax rates, the glow is enjoyed by officials and the chill by ordinary taxpayers.

It is the pattern I described in Ed Miliband’s carbon-capture crusade: policy as moral theatre, financed by somebody else. And it flourishes where the ordinary business of local government is neglected. ‘Woke’ councils seem to have far more time for planning environmental salvation than for potholes, or for easing the fines heaped on hated motorists in Sadiq Khan’s London. As my Daily Sceptic colleague Ben Pile reported last week, recycling centres across the country have been turning away old fridges and freezers, which are now piling up in laybys. Recycling is in trouble where it counts, and officialdom’s answer is another caddy.

The propensity to truck, barter and exchange

What would a rational policy look like? Britain already taxes the tip. The standard rate of landfill tax rose on April 1st to £130.75 a tonne. This tax is not an objective measure of real costs faced by society in getting rid of its rubbish. It is yet another ‘nudge’ by the nanny state to encourage producers to switch to ‘more sustainable alternatives’. ‘Sustainability’ is one of the great weasel words of the modern age, fully in keeping with those who would force taxpayers to ‘save the planet’.

Wandsworth Council should stick to its knitting. Council leaflets should tell residents the truth: that food recycling is a statutory compliance cost, not a saving, and that somebody is paying for it. Let voluntary, price-driven recycling of aluminium, cardboard and scrap metal, like other economic activity, take place by mutually consenting adults freely contracting with each other. Adam Smith argued that the “propensity to truck, barter and exchange” was inherent in human nature and gave rise to the division of labour. Hayek called the belief that a few well-meaning officials can know better than prices what is worth saving the fatal conceit. Wandsworth Council worthies should serve the local public good and let moralising behaviour be the free choice of its constituents.

This article was first published in the Daily Sceptic https://dailysceptic.org/2026/09/24/the-great-recycling-swindle/

Dr Tilak K. Doshi is the Daily Sceptic‘s Energy Editor. He is an economist, a member of the CO₂ Coalition and a former contributor to Forbes. Follow him on Substack and X.