Tag: Droughts

Colorado River Drought Triggers Unexpected Groundwater Collapse in the Upper Basin

Virginia Tech research (published in Water Resources Research) shows that recent severe drought in the Colorado River Basin has driven an unprecedented shift in groundwater depletion, with the historically more resilient Upper Basin now losing groundwater faster than the Lower Basin.

NASA’s GRACE (Gravity Recovery and Climate Experiment) satellites measure tiny changes in Earth’s gravity field to track how mass, especially water, moves around the planet.

GRACE’s strength is its ability to “weigh” large regions from space, capturing the total water mass change even where ground- based well networks are sparse.

A vast, arid landscape showcasing dry, cracked earth patterns, with steep rocky cliffs in the background and a thin body of water visible in the distance under a clear blue sky.
AI generated by Grok

Virginia Tech research (published in Water Resources Research) shows that recent severe drought in the Colorado River Basin has driven an unprecedented shift in groundwater depletion, with the historically more resilient Upper Basin now losing groundwater faster than the Lower Basin.

Declining river flows and falling levels in reservoirs like Lake Powell and Lake Mead are the visible signs of the long- running Southwestern megadrought. Underground, groundwater reserves- which supply a critical buffer for about 40 million people, agriculture, and ecosystems- are depleting rapidly, and the pattern has changed.

Historically, groundwater declined more in the Lower Basin (Arizona, southern Nevada, southeastern California). The system has now reached a turning point: the Upper Basin (Colorado, Wyoming, Utah, New Mexico) is experiencing rapid losses, with surface- water shortages increasingly affecting groundwater.

Researchers led by geosciences graduate student Esther Oyedele, working with assistant professor Susanna Werth and colleagues, isolated groundwater changes by combining NASA GRACE (Gravity Recovery and Climate Experiment) satellite measurements of total water storage with estimates of surface water, soil moisture, and snow-water storage for 2004- 2023.⁠

Key findings include:

  • Acceleration of groundwater depletion after 2019.
  • During the severe 2020- 2022 drought, the Upper Basin lost about 4.6 trillion gallons of groundwater, nearly double the Lower Basin’s estimated 2.5 trillion gallons.⁠

Oyedele noted: “We generally think of the Upper Basin as more resilient because of its snowmelt- driven recharge. I did not expect to see so much groundwater loss there during the recent drought. What surprised me even more was that groundwater did not track surface- water shortages in the same way in the Upper and Lower Basins.”

Groundwater and surface water are often connected; declining aquifers can reduce base flows into rivers, creating a feedback loop that worsens surface- water shortages. Continued depletion, especially in the Upper Basin, risks intensifying this cycle. Werth emphasized that managing surface water alone is no longer sufficient, protecting the basin requires treating water above and below ground as a connected resource.

The original study is available via DOI 10.1029/2025WR041695. The Virginia Tech news release by Kelly Izlar was published on October 13, 2026.

Map of the Colorado River Basin showing active management areas, irrigation zones, aquifers, reservoirs, and groundwater wells, with a small inset of the southwestern United States.
Map of the hydrogeological setting of the CRB and data applied in the study. Credit: Water Resources Research (2026). DOI: 10.1029/2025wr041695

NASA’s GRACE (Gravity Recovery and Climate Experiment) satellites measure tiny changes in Earth’s gravity field to track how mass, especially water, moves around the planet.

How GRACE works

GRACE does not take traditional “pictures” of Earth with cameras or radars pointed downward. Instead, the two nearly identical satellites themselves form the instrument.

  • The satellites fly in the same near- polar, low- Earth orbit (initially around 450- 500 km / 280, 310 miles altitude), one trailing the other by about 220 km (137 miles).
  • As they orbit, local variations in Earth’s gravity (caused by concentrations of mass below) pull on the lead satellite first, slightly speeding it up and increasing the distance to the trailing satellite. Moments later, the trailing satellite feels the same pull and the gap closes again.
  • A highly precise microwave ranging system (K/Ka-band) continuously measures these minuscule distance changes, to within about 1 micron (the diameter of a red blood cell, or roughly 1/100th the thickness of a human hair).
  • GPS receivers determine each satellite’s exact position relative to Earth. Onboard accelerometers measure non- gravitational forces (atmospheric drag, solar radiation pressure, etc.) so scientists can isolate only the gravitational effects.
  • Star trackers keep track of the satellites’ orientation.

From these data, scientists produce monthly maps of Earth’s gravity field. Differences between months reveal where mass has been added or removed.

What the measurements reveal

Because water has mass, changes in the amount of water stored on or below the surface alter local gravity. GRACE (and its successor GRACE- FO) can therefore detect:

  • Groundwater depletion or recharge in aquifers
  • Changes in soil moisture
  • Snow and ice mass loss or gain (glaciers, ice sheets)
  • Surface- water variations in large lakes, reservoirs, and rivers
  • Ocean mass changes related to sea- level rise and currents

The original GRACE mission flew from 2002 to 2017. GRACE Follow-On (GRACE-FO) launched in 2018 and continues the record (with an added experimental laser ranging interferometer for even higher precision). Together they provide a continuous multi- decade view of terrestrial water storage changes.

Relevance to the Colorado River Basin study

In the recent Virginia Tech research, scientists used GRACE/GRACE -FO total water storage data and subtracted independent estimates of surface water, soil moisture, and snow water. The remaining signal isolates groundwater storage changes. This is how they quantified the unexpected rapid groundwater losses in the Upper Basin during the 2020- 2022 drought.

GRACE’s strength is its ability to “weigh” large regions from space, capturing the total water mass change even where ground- based well networks are sparse.

Its spatial resolution is relatively coarse (typically hundreds of kilometers), so it is best for basin- or regional -scale studies rather than individual wells.

Figure (a): Cumulative distribution function of GWSIDI showing probability decrease with increasing values.
Example statistical copula model for bivariate comparison of GWSDI and SWSDI. —
Contrasting Groundwater Response to Surface Water Shortages in the Upper and Lower Colorado River Basins – Oyedele – 2026 – Water Resources Research – Wiley Online Library

Contrasting Groundwater Response to Surface Water Shortages in the Upper and Lower Colorado River Basins

Key findings from the abstract and plain- language summary

  • The study analyzes basin-scale terrestrial water storage and groundwater storage in the Colorado River Basin (CRB) from water year 2004- 2023 using GRACE/GRACE-FO satellite observations combined with hydrological datasets.
  • There has been sustained basin- wide groundwater depletion over two decades, with accelerated losses since 2019, especially during the severe 2020- 2022 drought.
  • During that recent drought:
    • Upper Colorado River Basin (UCRB) lost 17.5 ± 3.5 km³ of groundwater.
    • Lower Colorado River Basin (LCRB) lost 9.4 ± 6.5 km³.
    • (These volumes convert to roughly 4.6 trillion gallons in the Upper Basin and 2.5 trillion gallons in the Lower Basin, matching the press release figures.)
  • A copula- based statistical framework was used to quantify probabilistic relationships between storage- based drought indicators and to characterize groundwater- surface water interactions.
    • In the Upper Basin, there is strong coupling between surface- water deficits and groundwater drought probability (groundwater losses closely track surface- water shortages).
    • In parts of the Lower Basin, the statistical dependence is weaker, groundwater declines can occur somewhat independently of surface-water conditions, consistent with chronic human extraction under limited supply.

Broader context and implications

Groundwater is a critical buffer in the CRB, which supplies water to ~40 million people and extensive agriculture. The Upper Basin has traditionally been viewed as more resilient due to snowmelt-driven recharge, but the recent drought revealed greater vulnerability there. Continued depletion risks reducing groundwater contributions to river baseflow and intensifying feedback loops between groundwater loss and surface-water shortages.

The authors emphasize the value of satellite monitoring for large managed river basins and call for integrated water- management strategies that address both climatic pressures and sustained anthropogenic demand (above and below ground).

The full paper includes maps of the hydrogeological setting, GRACE mascon analysis, well data, and detailed statistical results. You can access the open- access version (including PDF download) directly at the DOI link above.

Journal: Water Resources Research,  (Volume 62, Issue 10)

DOI: 10.1029/2025wr041695

Provided: Virginia Tech

First published: 13 October 2026 (Open Access)

Authors:  E. O. Oyedele, S. Werth, G. Carlson (and others)

Abstract

Groundwater plays a critical role in sustaining the water supply in the Colorado River Basin (CRB), a region experiencing persistent drought, population growth, and increasing water demand. Using GRACE/GRACE-FO satellite observations combined with hydrological data sets, we analyze basin-scale variations and long-term trends in terrestrial and groundwater storage across the CRB from water year 2004–2023. We further apply a joint framework integrating copula-based statistical modeling with statistical inference to quantify probabilistic relationships among storage-based drought indicators and to characterize groundwater–surface water interactions. Results reveal sustained basin-wide groundwater depletion over the past two decades, with accelerated losses since 2019 and during the water year 2020–2022 drought. Notably, during this recent drought period, groundwater losses were larger in the typically more resilient Upper CRB (17.5 ± 3.5 km3) than in the Lower CRB (9.4 ± 6.5 km3), indicating increasing vulnerability across both subbasins. Copula-based analysis shows strong coupling between surface-water deficits and groundwater drought probability in the Upper CRB, whereas parts of the Lower CRB exhibit weaker statistical dependence, consistent with groundwater extraction operating partly independently of surface water availability under chronically limited supply conditions. These findings provide a basin-wide observational synthesis of groundwater–surface water dynamics and demonstrate the value of satellite-based monitoring for diagnosing hydroclimatic stress in large managed river basins. The results highlight emerging shifts in groundwater vulnerability across the CRB and underscore the need for integrated water-management strategies that jointly consider climatic pressures and sustained anthropogenic demand.

Nazca Lines: How an Ancient Desert Civilization Built Eternal Geoglyphs — and Why Climate Change Helped End It

The Nazca Lines (or Nasca geoglyphs) are a vast collection of large- scale designs etched into the desert floor of southern Peru’s Nazca Desert (Pampa Colorada and Pampa de Jumana), northwest of the modern city of Nazca.

The Paracas culture was an ancient Andean society that flourished on the arid southern coast of present- day Peru (primarily the Ica Region, including the Paracas Peninsula and valleys such as Chincha, Pisco, Ica, and parts of the Río Grande de Nasca drainage) roughly between 800 BCE and 100– 200 CE.

The Nazca (Nasca) civilization did not vanish suddenly or mysteriously.

The Nazca region receives almost no rainfall (often less than 1- 2 cm per year in the pampa).

Aerial view of the Nazca Lines in Peru showcasing large geoglyphs including a bird, spider, and humanoid figure etched into the desert landscape during sunset.
AI generated by Grok

The Nazca Lines (or Nasca geoglyphs) are a vast collection of large- scale designs etched into the desert floor of southern Peru’s Nazca Desert (Pampa Colorada and Pampa de Jumana), northwest of the modern city of Nazca. 

They include hundreds of straight lines (some running for many kilometers), geometric shapes (trapezoids, triangles, spirals, rectangles), and figurative designs of animals, plants, and human-like forms.

The figures range from tens to hundreds of meters long (e.g., a hummingbird ~50 m / 165 ft, a spider ~46 m / 150 ft, a monkey ~110 m / 360 ft, larger birds up to ~285- 370 m). The combined length of the lines exceeds 1,300 km, covering roughly 50- 500 km² depending on how the area is defined.

They were created mainly between about 500 BCE and 500- 600 CE (with the bulk associated with the Nazca period roughly 200 BCE- 600/700 CE). Some earlier examples are attributed to preceding cultures.

The Civilizations Behind Them

The primary creators were the Nazca (or Nasca) culture, which flourished on Peru’s southern coast between roughly 200 BCE and 600 CE in the river valleys of the Río Grande de Nasca drainage and the Ica Valley.

They were skilled agriculturalists in an extremely arid environment, relying on sophisticated underground aqueduct systems known as puquios to access and distribute water from Andean sources and aquifers. Their major ceremonial center was Cahuachi (a complex of adobe mounds and plazas), with Ventilla as a notable urban site. They produced distinctive polychrome pottery and fine textiles, and lacked a writing system.

Earlier groups contributed as well:

  • The Paracas culture (roughly 700/800 BCE- 1 CE or slightly later) is linked to some of the older geoglyphs, especially human- like or different stylistic figures, some on hillsides, and is seen as a cultural predecessor or strong influence on the Nazca.
  • Possible limited earlier involvement from groups related to the Chavín culture has also been suggested for some lines.

Newer designs sometimes overlap older ones, indicating creation and use over many centuries by successive groups rather than a single coordinated project.

The Nazca people were the main builders of the most famous animal and geometric figures.

How They Were Built

The method was simple, low- technology, and highly effective given the local geology, no advanced tools, wheels, metal, or aerial views were required. The desert surface consists of a layer of dark reddish- brown pebbles coated in iron- oxide “desert varnish.” Beneath this lies lighter yellowish- gray or white clay and sandy subsoil rich in lime.

Construction process (subtractive technique):

  1. Workers cleared the dark surface pebbles (typically to a shallow depth of 10- 15 cm / 4- 6 inches, though some descriptions note up to ~30- 40 cm in places), exposing the contrasting lighter soil.
  2. The removed stones were often piled or aligned along the edges of the lines and figures, creating a raised border that enhanced the visual contrast.
  3. For filled areas (e.g., interiors of trapezoids), stones were cleared from the whole surface and heaped at the margins.

This created high- contrast “drawings” that are best appreciated from the air or nearby hills but were made and used at ground level. The hyper- arid climate (minimal rain, little wind erosion at surface level) and the lime content (which hardens with moisture from mist) have preserved them for ~2,000 years.

Planning and precision techniques:

  • Designs were likely planned first at small scale (sketches, models, or possibly textile and grid patterns).
  • Wooden stakes, ropes and cords were used for layout. Stakes have been archaeologically recovered at the ends of some lines and radiocarbon- dated to the relevant period. Straight lines were made by stretching taut ropes between stakes (or successive stakes for long distances) and clearing along the guides; sighting along stakes helped maintain straightness over kilometers.
  • Curves, circles, and spirals used a central stake as a pivot with a rope of fixed or adjustable length (like a giant compass), releasing slack for expanding spirals.
  • Larger figurative designs could be scaled up proportionally from small models by measuring distances from centerlines or using grids and points, then connecting them. Experiments (including modern recreations of large figures like the condor using only stakes, rope, and a simple T- square by small teams) have demonstrated that this works efficiently without needing an overall aerial view.

Organized group labor under direction was involved, which may have reinforced social cohesion. The process did not require specialized engineering beyond basic geometry and surveying knowledge available to the culture. A minority view suggests some lines involved compacting/pressing the surface rather than full removal, but the consensus is the pebble- clearing method.

Purpose

The exact purpose remains debated and was likely multi- functional, evolving over time. Leading scholarly views emphasize ritual and ceremonial use in a water- scarce environment: processional paths for walking during religious rites (pottery offerings and compacted surfaces support this), connections between sacred sites (e.g., linking Cahuachi and other centers), and associations with water, fertility, mountain worship, and agriculture.

Some geometric lines may relate to water sources or puquios. Astronomical calendar theories (popularized by early researchers like Paul Kosok and María Reiche) have largely been weakened by later analyses showing limited alignments beyond chance. Fringe ideas (e.g., alien runways) lack evidence.⁠

In short, the Nazca Lines are a remarkable achievement of the Nazca people (building on Paracas foundations) using straightforward desert-surface clearing guided by basic stakes- and-ropes geometry, demonstrating sophisticated planning, communal effort, and cultural continuity in one of Earth’s driest places.

Geoglyph of a bird-like figure etched into the desert ground, showcasing linear patterns and designs.
The animal mounds were found in a region famous for a series of ancient geolyphs, called the Nazca Lines, which are now considered a World Heritage Site in the Nazca Desert in southern Peru. Here, Nazca Lines resembling a hummingbird, as viewed from a plane.
Nazca Lines Are a Labyrinth | Live Science

The Paracas culture was an ancient Andean society that flourished on the arid southern coast of present- day Peru (primarily the Ica Region, including the Paracas Peninsula and valleys such as Chincha, Pisco, Ica, and parts of the Río Grande de Nasca drainage) roughly between 800 BCE and 100– 200 CE.

It belongs mainly to the Early Horizon period and is named after the Paracas Peninsula (from a Quechua term meaning something like “sand falling like rain” or referring to sandstorms). The culture was first systematically investigated in the 1920s by Peruvian archaeologist Julio C. Tello (with Toribio Mejía Xesspe), who excavated major burial sites on the peninsula.

Chronology and Phases

Dates vary slightly by source and region, but a common range is c. 800- 700 BCE to 100- 200 CE. Traditional divisions include:

  • Paracas Cavernas (earlier phase): Characterized by bottle-shaped shaft tombs (“caverns”) cut into rock or earth, often reused over time, containing multiple burials with ceramics featuring post- fired resin paints, incised designs, and Chavín- influenced motifs.
  • Paracas Necropolis (later phase, associated with the Wari Kayan site): Larger subterranean chamber tombs or mausoleums with hundreds of elaborate individual mummy bundles. Some scholars link aspects of this phase more closely to the related Topará tradition.⁠

Radiocarbon studies refine phases in some areas (e.g., Early, Middle, and Late Paracas), and there was regional variation across valleys.

Society and Economy

Paracas society consisted of local chiefdoms rather than a centralized state. Communities shared religious ideas, trade networks, and cultural practices but retained political and economic autonomy. There is evidence of conflict (weapons, trophy heads, battle wounds).⁠

They adapted to an extremely dry desert environment next to a rich Pacific coastline by practicing agriculture (supported by irrigation and water management in river valleys), fishing, and gathering marine resources. Cotton was grown locally, and they engaged in reciprocal trade with highland groups, notably those linked to the Chavín culture (whose religious iconography influenced early Paracas art).

Key Achievements and Material Culture

  • Textiles: Paracas is renowned for some of the finest pre- Columbian Andean fiber arts. Mummy bundles were wrapped in multiple layers of cotton and camelid (llama, alpaca and vicuña) wool textiles featuring complex techniques: embroidery (linear and block- color styles), tapestry, gauze, twining, looping, braiding, featherwork, and more. Designs often depict mythological beings, anthropomorphic figures, animals, and geometric patterns. Elite bundles could be massive and highly elaborate.⁠
  • Ceramics: Early styles used post- firing resin paints applied within incised lines; later ones included slipped and burnished wares. Motifs often featured felines, birds, and other creatures.
  • Burial practices: Strong belief in the afterlife is evident in carefully prepared mummy bundles (bodies seated and flexed, often with false heads, grave goods like food, ceramics, tools, weapons, and musical instruments). Some tombs were reused; cranial modification (intentional head shaping in infancy into tabular or bilobate forms) was practiced, possibly for status or identity. Trepanation (skull surgery) also occurred.
  • Other: They produced basketry, pyro- engraved gourds, and items reflecting musical performance. Some early geoglyphs in the broader region (including hillside figures and the Paracas Candelabra) are attributed to them and predate the classic Nazca Lines.

Relation to the Nazca Culture

The Paracas culture is widely regarded as the direct predecessor (or cultural foundation) of the Nazca (Nasca) culture.

Nazca society (c. 200 BCE- 600/700 CE) inherited and developed Paracas traditions in textiles, religion, iconography, head- related rituals, and adaptation to the desert environment (including later advances in underground aqueducts). The transition involved continuity in some areas alongside innovations (especially in pottery techniques, with Nazca developing pre- fired polychrome slips) and possible influences or population movements involving the Topará tradition. Some of the earliest Nazca Lines and geoglyphs show Paracas stylistic links.

In summary, the Paracas people created a sophisticated coastal culture known especially for extraordinary textiles and complex mortuary rituals in one of the world’s driest environments. Their legacy provided the cultural and artistic foundation for the better-known Nazca civilization that followed.

Infographic depicting the evolution of Paracas ceramics, showcasing key phases and significant artifacts from 840 BCE to 300 CE.
Timeline signifying the evolution of Paracas Ceramics. Paracas culture – Wikipedia

The Nazca (Nasca) civilization did not vanish suddenly or mysteriously.

It declined gradually over centuries, primarily between roughly 500 and 750 CE, due to a combination of environmental degradation (partly self- inflicted), climate stresses, social changes, and eventual absorption or displacement by later groups such as the Wari. The people themselves did not disappear; their distinct cultural complex transformed and faded as a recognizable entity.

Environmental Self-Sabotage and Climate Events

A key factor was the progressive clearing of native huarango trees (Prosopis pallida, also known as algarrobo).

These deep- rooted, long- lived trees acted as a keystone species in the arid river valleys: they stabilized soil against erosion, helped retain moisture, protected against winds, and supported fertile floodplains. Pollen records from sites like the lower Ica Valley show that as Nazca agriculture expanded (for maize, cotton, beans, and other crops), huarango pollen declined sharply while crop pollen rose, especially from about 200- 400 CE onward. By around 500 CE, woodland clearance had crossed an ecological tipping point in the fragile desert environment.

This left the landscape highly vulnerable. A major El Niño event (or series of extreme floods) around 500- 600 CE then caused severe damage: rivers cut deeply into unprotected floodplains, irrigation systems (including canals and possibly puquios) were wrecked or left high and dry, soil eroded, and agricultural land was degraded or salinized.

What might have been manageable replenishment of water tables instead became catastrophic because the natural buffers were gone.

Some research also points to increasing aridity, drought periods (possibly multi -decade), and other stresses like earthquakes or moderate debris flows contributing to progressive environmental pressure, particularly affecting ceremonial centers like Cahuachi (largely abandoned earlier, around the end of Early Nazca phases).

After these events, settlements fragmented, evidence of conflict and warfare imagery increased in art, health indicators worsened in some populations (higher infant mortality, shorter lifespans), and large- scale communal projects (including geoglyph construction) became harder to sustain.

Social and Political Transitions

The Nazca were never a highly centralized state but a collection of related chiefdoms with shared culture, religion, and iconography.

Environmental stress weakened social cohesion and the authority of ceremonial centers. In the Middle Horizon (roughly 600- 1000 CE), the expanding highland Wari (Huari) culture exerted influence or control over the region. Some Nazca groups appear to have been incorporated, with Wari adopting or adapting certain Nazca artistic traits; other areas saw abandonment or migration (possibly to higher elevations or better- watered zones). Later, the region was reoccupied in the Late Intermediate Period by societies with highland immigrant influences.

There is no strong evidence of a single military conquest that wiped them out overnight, nor of mass extinction. Population levels dropped in core areas, settlements shifted, and the distinctive Nazca pottery styles, textile traditions, and ritual practices gradually blended into or were replaced by successor cultures.

Summary of the Process

  • Gradual environmental damage (deforestation for farmland) reduced resilience.
  • Climate shocks (El Niño floods, aridification and drought) damaged agriculture and infrastructure.
  • Social fragmentation followed, with reduced ceremonial activity and increased conflict.
  • Cultural absorption and transition into the Wari sphere and later societies completed the transformation of the “Nazca civilization” as a distinct archaeological culture by around 750 CE.

The famous Nazca Lines and other achievements endured precisely because of the hyper- arid conditions that both challenged and preserved them. Modern studies of this history often highlight lessons about sustainable land use in fragile ecosystems facing climate variability.

A panoramic view of archaeological ruins in the foreground with a mountain range in the background and a road running through a green landscape.
Los Paredones, Nazca, Peru
Nazca – Wikipedia

The Nazca civilization developed and ultimately declined in one of the world’s driest environments, the hyper- arid coastal desert of southern Peru, where climate and water availability were central to daily life, agriculture, religion, and long- term survival.

The Climate Context

The Nazca region receives almost no rainfall (often less than 1- 2 cm per year in the pampa).

Life depended on seasonal river flow from Andean snowmelt and rainfall higher in the mountains, plus groundwater. The people engineered sophisticated responses, including the famous puquios (underground aqueducts and filtration galleries) that tapped aquifers and minimized evaporation, allowing agriculture of maize, cotton, beans, squash, and other crops in river oases.

Climate was never stable. Paleoclimate records (pollen, sediments, desert loess, ice cores from Quelccaya, and other proxies) show fluctuations between relatively more humid and more arid phases, influenced by the El Niño- Southern Oscillation (ENSO), shifts in monsoonal moisture from the east, and broader Andean patterns.

Key Climate Impacts on the Nazca

  • Gradual aridification and desertification: Starting around 150 CE (and intensifying 350- 400 CE), a progressive drying trend began. The eastern margin of the Atacama Desert shifted inland and up-valley. Settlement centers moved upstream into higher valleys to follow remaining water sources. Periods of multi- decade water scarcity (up to ~80 years in some reconstructions) occurred, yet the culture continued to produce fine pottery and maintain ceremonial centers like Cahuachi for a time.⁠
  • Droughts: Stronger drought episodes, including one in the 5th century CE and a more extreme phase around or after 600 CE, stressed agriculture and water systems. These contributed to reduced productivity, settlement shifts, and the eventual decline of the classic Nazca cultural complex. Some researchers link the construction or expansion of puquios partly to adaptive responses to these drier conditions.
  • El Niño events and floods: El Niño typically brings heavy rains and flooding to the Peruvian coast. A major (or “mega”) El Niño event around 500- 600 CE is documented in some valleys (especially the lower Ica). Floods damaged irrigation infrastructure and farmland. However, the impact was greatly amplified by prior human deforestation of huarango trees, which had stabilized soils and floodplains. Without that natural buffer, erosion intensified and systems failed more catastrophically. Some earlier catastrophic-flood theories for the complete burial of sites like Cahuachi have been challenged; evidence points more toward progressive environmental stress, moderate floods, earthquakes, and increasing aridity rather than single mega- floods wiping everything out.⁠
  • Increased climate variability: Toward the end of the Early Intermediate Period (~600 CE) and into the Middle Horizon, precipitation became less predictable (more frequent droughts mixed with occasional flash floods). This reduced agricultural reliability and contributed to social stress, possible conflict over water, abandonment of lower valleys, and population movements (including some migration toward higher elevations).

Adaptation and Limits

The Nazca showed significant resilience: they expanded irrigation, shifted settlements, intensified ceremonial activities (possibly related to water and fertility rituals, including geoglyph construction during drier periods), and maintained complex society for centuries under difficult conditions. Their cultural peak occurred despite ongoing aridification.

However, the combination of long- term drying, extreme events, and human modifications of the landscape (especially tree clearance for farmland) eventually exceeded adaptive capacity.

By roughly 600- 750 CE the distinctive Nazca cultural pattern declined, with many areas abandoned or absorbed into the expanding Wari sphere. Later (Late Intermediate Period) more humid conditions allowed reoccupation of some zones.

In short: Climate, particularly progressive aridification, drought, and ENSO- related extremes, was a major driver of both the Nazca’s impressive adaptations (irrigation, water rituals) and their eventual transformation as a civilization. Modern researchers often study these dynamics for insights into resilience and vulnerability in dryland societies facing climate variability today.

Ancient Jerusalem’s Climate Crisis: How the City of David Battled Drought and Floods 2,800 Years Ago

Climate has profoundly shaped the City of David (the original core of ancient Jerusalem on the southeastern ridge), primarily through its effects on water availability. The site’s location was chosen around the perennial Gihon Spring, the only reliable local water source in an otherwise semi- arid environment. Fluctuations in rainfall, droughts, and extreme weather over the last 3,000 and more years directly influenced settlement size, fortifications, water engineering, agriculture, and periods of growth or stress.

A dramatic landscape featuring a stormy sky over ancient ruins, with rushing water from Gihon Spring flowing towards Siloam Dam, surrounded by dry, cracked earth and distant hills.
AI generated by Grok

The City of David (Hebrew: ʿĪr Davīd; also known locally in Arabic as Wadi Hilweh) is the archaeological site widely regarded as the original settlement core of ancient Jerusalem during the Bronze and Iron Ages.

It occupies a narrow, elongated ridge (the southeastern hill) immediately south of the Temple Mount, Ophel saddle, west of the Kidron Valley and east of the Tyropoeon Valley. The Gihon Spring, the ancient city’s primary water source, lies on its eastern slope. This location made it defensible and strategically important from the earliest periods of settlement.

According to the Hebrew Bible (e.g., 2 Samuel 5), King David conquered the Jebusite city (often called Zion or Jebus) around 1000 BCE and established it as his capital, renaming or identifying it as the “City of David”.

Later kings, including Solomon, expanded the city northward toward the Temple Mount. The site remained the core of Jerusalem through the Kingdom of Judah until the Babylonian destruction in 586 BCE, and occupation continued into later periods, including the Second Temple era.

Archaeologically, permanent settlement evidence begins in the Early Bronze Age (3rd millennium BCE), with major fortifications appearing in the Middle Bronze Age (around the 18th century BCE) around the Gihon Spring. The site is central to debates about the scale and nature of Jerusalem in the 10th- 9th centuries BCE (the traditional United Monarchy period).

Major Archaeological Features and Discoveries

  • Gihon Spring fortifications and water systems: Middle Bronze Age walls, towers, and passages protected the spring. Later systems include Warren’s Shaft and Channel II.
  • Stepped Stone Structure and Large Stone Structure: Massive Iron Age constructions. The Stepped Stone Structure is one of the largest known Iron Age man- made features in Israel (over 20 m high). Eilat Mazar interpreted the adjacent Large Stone Structure as a monumental public building (possibly linked to a royal or administrative complex from the time of David or shortly thereafter). Dating and exact identification remain debated among scholars.
  • Siloam Tunnel (Hezekiah’s Tunnel) and Pool of Siloam: A famous water tunnel traditionally associated with preparations for the Assyrian siege under Hezekiah (late 8th century BCE), though some evidence suggests earlier origins. The Pool of Siloam and the adjacent stepped street (Pilgrimage Road) were major features in the Second Temple period.
  • Iron Age city walls and other fortifications: Segments of the mid- slope fortification (Kenyon- Shiloh Wall) from the 8th century BCE and earlier; a massive rock- cut moat and trench separating the City of David ridge from the Ophel and Temple Mount area, used during the Kingdom of Judah period.
  • Other finds: Bullae (seal impressions), pottery, destruction layers from 586 BCE, a unique First Temple-period ritual structure with rock- hewn rooms (altar, standing stone, oil and wine presses) that may have gone out of use during Hezekiah’s reforms, and extensive Second Temple remains.

Recent radiocarbon studies (sampling organic material from multiple areas) support significant activity already in the 10th century BCE and earlier westward expansion of the city (toward Mount Zion) by the 9th century BCE, refining older chronologies.

The City of David is part of the Jerusalem Walls National Park and a major tourist site operated with visitor centers, guided tours, the Pilgrimage Road, access to the Siloam Tunnel (often by flashlight), and interpretive exhibits. It continues to yield new finds through ongoing salvage and research excavations by the Israel Antiquities Authority, Hebrew University, and other teams.

In short, the City of David is the archaeological heart of ancient Jerusalem- providing the physical evidence for its earliest urban phases, water management, fortifications, and continuous development over millennia- while remaining a focal point for both scholarly debate and public interest in biblical archaeology.

Ancient stone walls and ruins with a domed structure in the background under a blue sky.
Shake yourself from the dust, rise up, O captive Jerusalem; Loose yourself from the chains around your neck, O captive daughter of Zion. –Isaiah 52:2
The City of David: The Jerusalem That You Don’t Know

Climate has profoundly shaped the City of David (the original core of ancient Jerusalem on the southeastern ridge), primarily through its effects on water availability. The site’s location was chosen around the perennial Gihon Spring, the only reliable local water source in an otherwise semi- arid environment. Fluctuations in rainfall, droughts, and extreme weather over the last 3,000 and more years directly influenced settlement size, fortifications, water engineering, agriculture, and periods of growth or stress.

Paleoclimate Context for the Southern Levant and Jerusalem

High- resolution proxies, including Dead Sea sediment cores (which act as a regional “rain gauge”), speleothems from nearby caves such as Soreq (recording precipitation via isotopes), pollen records, and solar activity indicators, reveal multi- decadal to multi- centennial climate swings rather than a stable climate.

Key patterns relevant to the last ~3,000 years (roughly Iron Age onward):

  • A ~150- year arid phase at the end of the Late Bronze Age (around the 13th- 12th centuries BCE) contributed to societal disruptions across the eastern Mediterranean.
  • Wetter conditions returned in Iron Age I, supporting highland settlement expansion and the rise of early kingdoms.
  • Iron Age II conditions were generally moderate (closer to modern averages), but with notable variability, including drier intervals and flash- flood events.
  • Later periods (including Roman, Byzantine, and medieval) also show oscillations, with lower groundwater recharge during cooler and drier epochs (e.g., parts of the Iron Age Cold Epoch and Little Ice Age) and higher recharge in warmer and wetter intervals.

Overall, the region experienced a long- term drying trend through much of the Holocene, punctuated by wetter and drier episodes. Climate alone rarely caused total collapse; societies often adapted through engineering, agricultural changes, and resilience strategies.

Specific Impacts and Adaptations at the City of David

Water security was existential. Drought reduced spring discharge and crop yields, while intense storms caused erosion, flash floods in the Kidron and Tyropoeon valleys, and soil loss. Archaeological evidence shows repeated investment in water infrastructure as a response:

Late 9th century BCE (ca. 805- 795 BCE), Siloam Dam: Radiocarbon dating of organic material in the mortar pins construction of this massive dam (blocking the Tyropoeon Valley to create/expand the Siloam Pool) to a narrow decade. Climate data from Dead Sea cores show increased aridity (halite layers) plus evidence of torrential rains and floods around 850- 800 BCE. Soreq Cave stalagmites indicate minimum precipitation near 850 BCE. This coincides with the Homeric Grand Solar Minimum (reduced solar activity linked to climate shifts). The dam stored water from the Gihon Spring and captured flood runoff, securing supply during dry spells while managing flood risk. It forms part of a broader late- 9th and early- 8th- century expansion of Jerusalem’s water systems.

Hezekiah’s Tunnel and related works (late 8th century BCE): Traditional association with preparations for the Assyrian siege, but these systems also enhanced resilience to climatic variability by protecting and redirecting the spring’s flow underground.

Broader Iron Age patterns: Radiocarbon- dated sequences from City of David excavations show continuous settlement and architectural development from the 12th- 10th centuries BCE onward, with westward expansion by the 9th century and major fortification after a mid- 8th- century earthquake. Climate variability is one factor among others (political, economic, seismic) influencing these dynamics. Desert- fringe areas felt climatic impacts more strongly than core highland zones like Jerusalem.

Longer- term groundwater and vegetation: Modeling of the Jerusalem region over ~4,500 years shows precipitation- recharge relationships remained relatively linear despite temperature and vegetation changes, though drier decades reduced recharge efficiency. Human impacts (deforestation, overgrazing, terracing, fruit- tree cultivation) further modified the local environment.

Summary of Climate- Human Interaction

In the City of David, climate impacts manifested mainly as water stress and flood risk. Rather than abandonment, the archaeological record documents sophisticated engineering responses, dams, tunnels, pools, and fortifications, that allowed the settlement to grow into a significant urban center. These adaptations highlight both vulnerability (dependence on a single spring and rainfall- dependent agriculture) and ingenuity. Modern parallels exist: the eastern Mediterranean continues to face drying trends and water challenges, making the ancient record relevant for understanding long- term resilience.

Ongoing excavations and multi- proxy climate studies continue to refine these connections, showing that climate was an important but not solitary driver of change at the site.

A detailed model of an ancient city, labeling key locations such as Mount Moriah, Ophel, Palace, Gihon Springs, Central Valley, and Kidron Valley.
The City of David – Jerusalem 101

The Homeric Grand Solar Minimum (also called the Homeric Minimum or Homerian Climate Anomaly) was a prolonged period of unusually low solar activity that began around 800 BCE and lasted roughly 200 years (approximately 2750- 2550 cal BP, with a stronger phase early on).

It is detected through elevated levels of cosmogenic isotopes such as carbon-14 (in tree rings and the atmosphere) and beryllium-10 (in ice cores and lake sediments).

These indicate reduced solar magnetic shielding, allowing more cosmic rays to reach Earth.

The event is sometimes linked to a broader “Hallstatt” solar minimum complex and coincided with a geomagnetic excursion (Etrussia- Sterno).

Climate Effects

In Europe (especially western and central), it is associated with colder, wetter, and windier conditions (the “Homeric Climate Oscillation” or 2.8 ka event).

In the eastern Mediterranean and Levant, regional proxies point to a different response: overall reduced precipitation (aridity), combined with intermittent intense rainstorms that produced flash floods.

Key evidence near Jerusalem includes:

  • Dead Sea sediment cores showing increased aridity (halite deposition) beginning around 850 BCE, along with graded layers indicating floods.
  • Soreq Cave speleothems (about 20 km west of Jerusalem) recording minimum precipitation near 850 BCE, followed by a gradual recovery.
  • Supporting signals from pollen and isotopic data on olive pits indicating shifts in rainfall patterns around 830 BCE.

Connection to the City of David

Researchers directly link this solar- driven climate shift to major water engineering in Jerusalem’s City of David. Precise radiocarbon dating of microscopic organic material (straw and twigs) in the mortar of the Siloam Dam places its construction in a narrow window of 805- 795 BCE.

The dam (a large stone structure that blocked the Tyropoeon Valley) created or expanded the Siloam Pool. It was part of a coordinated system that:

  • Fortified and protected the Gihon Spring (the city’s main water source).
  • Redirected spring water through channels into the artificial reservoir.
  • Captured both spring flow and flood runoff for storage during dry periods while managing destructive flash floods.

This project is attributed to the early Kingdom of Judah, likely under King Jehoash or his successor Amaziah.

It represents sophisticated urban planning to cope with the unpredictable weather (prolonged dry spells punctuated by violent rains) associated with the Homeric Grand Solar Minimum. The scale of the works underscores Jerusalem’s importance and organizational capacity at the time.

In short, the Homeric Grand Solar Minimum provides a climatic backdrop for one of the City of David’s most impressive Iron Age water systems, illustrating how ancient Jerusalem adapted to solar- influenced climate variability through large- scale engineering.

A detailed archaeological map showing the Southeastern Ridge, highlighting the Gihon Spring, Siloam Tunnel, and nearby landmarks.
(A) The study sites. Graphics by Manuel Cimadevilla, Israel Antiquities Authority. (B) The Siloam Dam excavation. Arrows mark the sampling locations. (C) A representative straw fragment embedded in the mortar.
Radiocarbon dating of Jerusalem’s Siloam Dam links climate data and major waterworks | PNAS

Wrong, Deutsche Welle, There Is No Such Thing as a “Super El Niño,” Nor Is it on Team Climate

Deutsche Welle (DW) claims in “How climate change is teaming up with ‘Super El Nino” that a developing “Super El Niño,” combined with climate change, could make 2026 one of the hottest years on record while increasing the risks of heat waves, wildfires, droughts, hurricanes, and marine heat waves around the world. This is highly misleading.

From ClimateRealism

By Anthony Watts

Deutsche Welle (DW) claims in “How climate change is teaming up with ‘Super El Nino” that a developing “Super El Niño,” combined with climate change, could make 2026 one of the hottest years on record while increasing the risks of heat waves, wildfires, droughts, hurricanes, and marine heat waves around the world. This is highly misleading. El Niño are long-recognized naturally recurring ocean-atmosphere cycles that have operated for thousands of years and strong El Niño events have occurred periodically throughout history, long before industrial greenhouse gas emission began to increase.

The first red flag appears in the headline itself. There is no official meteorological definition of a “Super El Niño.”

Neither the World Meteorological Organization, the National Oceanic and Atmospheric Administration’s Climate Prediction Center, nor the American Meteorological Society recognizes “Super El Niño” as a formal scientific classification. Meteorologists describe El Niño events by measuring sea surface temperature anomalies in the Niño 3.4 region of the tropical Pacific. They may characterize an event as weak, moderate, strong, or very strong, but “Super El Niño” is largely a media invention designed to make a naturally occurring climate pattern sound unprecedented.

That alone should make readers skeptical.

El Niño is not a new phenomenon, nor is it evidence of climate change. Long before automobiles, coal-fired power plants, or industrial emissions existed, El Niño events periodically warmed the tropical Pacific Ocean, temporarily altering normal weather patterns around the globe. Paleoclimate records from corals, lake sediments, and other shell middens, and other proxy data show that El Niño events have repeatedly occurred for thousands of years.

Nothing about its existence is evidence of a climate crisis. DW also suggests that climate change is “teaming up” with El Niño to produce record warmth.

That statement reverses cause and effect.

El Niño transfers enormous amounts of stored ocean heat into the atmosphere. That is precisely why global temperatures often spike during strong El Niño years and then decline as La Niña conditions return. This pattern has repeated for centuries.

The strong 1997-98 El Niño produced record global temperatures.

The powerful 2015-16 El Niño did the same.

More recently, the 2023-24 El Niño contributed to another jump in global temperatures before they began moderating as the event weakened. There is nothing unprecedented about this sequence, which is made clear in the Figure below.

Figure: Oceanic Niño Index from the NOAA Climate Prediction Center. Plotted by Meteorologist Jan Null.

It is exactly what climatologists expect from a strong El Niño. DW further claims that El Niño could intensify heat waves, wildfires, droughts, hurricanes, and marine heat waves around the world.

Some of those statements contain a speck of truth, but mostly they are misleading talking points.

El Niño does influence weather patterns globally. It can make some regions temporarily wetter and others drier. It can suppress Atlantic hurricane activity while increasing hurricane activity in parts of the Pacific. It affects rainfall, temperatures, and storm tracks across much of the globe.

But that is very different from claiming El Niño automatically causes more weather disasters worldwide.

Wildfires depend on ignition sources, fuel loads, forest management, humidity, and local weather. Heat waves have occurred throughout recorded history, long before anyone worried about greenhouse gases. Droughts and floods are influenced by regional circulation patterns that vary considerably from one El Niño event to another.

Simply invoking El Niño and climate change together does not establish that either is responsible for any particular extreme weather event, much less every such event. DW also repeats a common media refrain that climate change remains “the main driver” of rising temperatures while El Niño merely amplifies its effects.

That claim is presented as settled fact, but no evidence is offered by DW to support it.

In reality, year-to-year changes in global temperature are overwhelmingly dominated by natural variability, particularly the transition between El Niño and La Niña. That is why global temperatures can rise sharply during a strong El Niño and then level off or even decline afterward. Over decades and centuries, other natural oceanic current patterns, like the Atlantic Meridional Overturning Circulation and the Pacific Meridional Overturning Circulation are significant factors in climate change as they redistribute ocean heat.

Natural variability remains a major driver of short-term climate fluctuations. Perhaps the biggest journalistic failure is that DW never distinguishes between weather forecasting and climate attribution.

Forecasting that a strong El Niño may influence global weather over the coming months is reasonable science. Claiming that climate change is “teaming up” with El Niño to produce nearly every type of extreme weather is speculation. Those are not the same thing.

The article also hints that 2027 could be even hotter, despite acknowledging that the future evolution of El Niño remains uncertain. That is another projection built upon assumptions, not observations.

No one knows today what the global average temperature will be in 2027 because it will depend on countless variables, including the evolution of ENSO, volcanic activity, cloud cover, ocean circulation, and other natural influences that cannot be predicted with certainty years in advance.

Good journalism should help readers understand the difference between natural climate variability and long-term climate trends. DW’s story linking the developing strong El Niño to climate change is not good journalism.

Readers deserve better than catchy labels and speculative headlines. They deserve reporting that distinguishes between what scientists actually know, what climate models project, and what remains uncertain. In this case, DW chose drama over clarity, turning one of Earth’s oldest natural climate cycles into yet another vehicle for climate alarmism.

Claim: Climate Driven Droughts Will Triple the Price of Wheat

The study notes there has been a significant increase in prices since 2000, leading to more global hunger.

Interestingly though they claim a shift in growing regions would not fix the problem.

They completely missed the impact of biofuels on recent food prices.

From Watts Up With That?

Essay by Eric Worrall

Because people will forget how to build water infrastructure?

AUGUST 21, 2026

Climate change could triple the price of wheat

by Camilla Brodam Galacho, Aarhus University
edited by Gaby Clark, reviewed by Robert Egan

…

Among the co-authors is Jørgen E. Olesen, professor and head of the Department of Agroecology at Aarhus University.

“We already know that climate change affects agricultural production. What is new here is that we can document a clear link between widespread drought across the globe and the prices faced by consumers and food markets,” he says.

…

Historical data show that, on average, around 5% of the world’s wheat-growing area has experienced severe water scarcity in any given year. However, this share has increased alongside climate change, and in particularly dry years such as 2000, 2010, 2012 and 2020, it exceeded 15%.

The research team then used climate models to explore how this trend may develop in the future. The study suggests that severe water scarcity will spread across larger portions of the world’s wheat-growing regions as temperatures continue to rise.

At around 2 degrees of global warming, the model estimates an average wheat price of approximately USD 273 per tonne. At 3 degrees of warming, that figure rises to about USD 364 per tonne, roughly three times the inflation-adjusted global wheat price recorded in 2010.

…Read more: https://phys.org/news/2026-08-climate-triple-price-wheat.html

The abstract of the study;

Climate-Induced Severe Water Scarcity Events as Harbingers of Global Wheat Price

Miroslav Trnka, Jan Meitner, Jan Balek, Song Feng, Juliana Arbelaez Gaviria, Milan Fischer, Esther Boere, Petr Havlík, Kurt-Christian Kersebaum, Claas Nendel, Margarita Ruiz-Ramos, Daniela Semerádová, Mikhail A. Semenov, Markéta Poděbradská, Jan Esper, Ulf Büntgen, Max Torbenson, Jáchym Brzezina, Zdeněk Žalud, Gabriel Katul, Jørgen E. Olesen

First published: 21 August 2026

Abstract

This study connects the dots between global extent of severe water scarcity (SWS) events and spikes in food price. The authors start with three staple crops (rice, wheat, and maize) using a empirical but crop specific characterization of severe water scarcity occurrence, which is defined based on the area of land cultivated with each studied crop that on a given year is under SWS conditions. Water scarcity is estimated based on 1, 3, and 12 months standardized precipitation evapotranspiration index during crop specific sensitive periods (SPs). SPs coincide with the 4 months prior to harvest. A SWS-wheat price relationship model was developed for period 2001–2021 and tested for 1986–2000 and 2022–2024 with future projections calculated under climate change using climate model simulations from CMIP5 and CMIP6 up to 2100. The results show a marked increase in wheat prices driven by increasing SWS area, which is in turn a function of greenhouse gas emissions. The results indicate that the meanglobal mean temperature increase by 3°C (compared to 1951–1980) could lead to the tripling of the mean global wheat price compared to 2010 (after deflating).

Plain Language Summary

Water scarcity is a growing threat to global food production, particularly for crops that depend on rainfall rather than irrigation. When soils do not receive enough moisture during key growing periods, harvests can fail, and food prices can rise. In this study, we introduce a new way to track severe water scarcity (SWS) by measuring the area of cropland affected during sensitive stages of crop growth. We apply this method to major staple crops and examine how changes in SWS are associated with global food prices. We find a clear link between the area affected by severe water scarcity and global wheat prices. Years with larger affected areas tend to coincide with higher prices. Looking ahead, climate model projections suggest that water scarcity will expand under continued warming. Our results indicate that a temperature increase of about 3°C could triple average global wheat prices relative to 2010. These findings highlight the risks climate change poses to global food security and the consequences of more frequent water shortages in agriculture.

Read more: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025EF006095

The study notes there has been a significant increase in prices since 2000, leading to more global hunger;

… Approximately 14% of global cereal production is traded internationally, with 90% of these exports generated by the top 10 producing countries. While wheat, maize, and rice production has steadily increased over the past 60 years, the prices of these cereals showed a marginal overall increase between 1960 and 2000, followed by significant increases over the past 24 years. Among the three crops, wheat is a particularly volatile commodity (Conceição & Mendoza, 2009) exhibiting punctuated growth. During the grain price crises of 2007/08, 2010/11 and 2021/22, wheat prices increased by 97%, 46%, 64%, respectively, relative to the preceding years of increased prices. In comparison, rice prices changed by 124%, 2%, and −4%, respectively, and maize prices changed by 79%, 70%, and 66%, respectively in these years (IGC, 2022). Of far greater concern is the number of undernourished individuals. This number increased from 598 million in 2010 to 735 million by 2020 (FAO, 2022), an increase of 23% in 12 years. …

And the magic words, which indicate how unrealistic the projection scenario is;

… The results of our study indicate that projected increase in the SWS extent and frequency may result (if other parameters are kept the same) to quite high increase of the wheat prices. … The projected increase in food price impacts of SWS events thus require urgent attention in terms of adaptation measures on the one hand and disaster-relief systems on the other hand.  …

Interestingly though they claim a shift in growing regions would not fix the problem;

…

4.2 Study Assumptions

The estimates of crop price response to SWS builds on a number of assumptions, which were invoked to ensure that the SWS extent is primarily a function of changing climate conditions. It was assumed that the current wheat-growing areas, their relative weights and the top 10 exporting countries would remain unchanged during the time frame of the analysis. Thus, the potential benefit of shifting wheat production to other agricultural land with a lower SWS probability could lower the model reliability. However, two findings suggest that the conclusions drawn here are little sensitive to this simplification. First, two out of the four models in the final model ensemble are based on SWS occurrence across the entire arable land area; thus, a change in the wheat-growing area would generate no effect. Second, the data revealed that there is little to be gained globally in terms of decreasing SWS exposure by shifting wheat-producing areas both within and outside the present wheat-growing areas, as SWS exposure increases at a similar pace across all regions as already shown by Trnka et al. (2019).

…Read more: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025EF006095

Their conclusion is their projection is robust –

… Regardless of the discussed assumptions, the SWS–wheat price relations could be in our view considered robust and warrant their inclusion in the projected impacts of the SWS-affected area on wheat prices. In light of the crop price volatility over past 20 years, the projected increase in space‒time coherent SWS occurrence cannot be overlooked in any estimates of future price levels, at least in the case of wheat and to some extent maize. …

I think the biggest weakness is the failure to model adaption to changed conditions beyond simple changes to growing regions. The main reason farmers haven’t invested in sufficient water infrastructure to mitigate those 5-15% of production area severe water shortage years is it isn’t worth the investment. But if the price of wheat was to rise significantly, the value of producing wheat would justify far greater investment in reservoirs and if necessary desalination plants.

In addition the study fails to mention biofuel mandates as a driver of recent price increases – at one point the problem go so severe, even President Obama pulled back from funding starvation in poor countries.

Food Prices and Ethanol Mandates

And of course there is the fundamental reality that like many climate models, this food price model contradicts evidence that climate change and CO2 fertilisation is driving an abundance of food production. Future increases in drought are speculation, the evidence is industrial CO2 emissions are good for food availability.

Aussie Growing Conditions which Produced Record Harvests are now “Climate Whiplash”

In my opinion this study is a pretty poor effort. The study authors at least mentioned adaption as a viable mitigation study, but didn’t explore in depth the most obvious adaption, investment in water infrastructure. They completely missed the impact of biofuels on recent food prices. And their language is unnecessarily alarmist. I would have had a lot more respect for the authors if they had couched the study as “more water infrastructure required”, rather than headlining with emotionally laden terms like “Harbinger” in the title of their study.

Climate Fact-Check July 2026

Editor’s note: This compilation serves as a fact check on the most widespread false claims made about climate change by the media in July, 2026.

‘Climate change’ is NOT causing droughts, heatwaves, shrinking squid brains, wildfires, snow droughts & more tornadoes

From ClimateRealism

Guest Post by: The Committee for a Constructive Tomorrow, The Heartland Institute, the Competitive Enterprise Institute, the Energy & Environmental Legal Institute, and the International Climate Science Coalition, and Truth in Energy and Climate.

Editor’s note: This compilation serves as a fact check on the most widespread false claims made about climate change by the media in July, 2026.

‘Climate change’ is NOT causing droughts, heatwaves, shrinking squid brains, wildfires, snow droughts & more tornadoes

Links: PBS News report, NOAA NCEI data.
Links: National Academies report, 2004 University of Arkansas study, Journal of Paleolimnology 2012 paper, NCEI data on drought frequency and severity.
Links: New York Times story, World Weather Attribution claim, warm bias documentation, urban temperature station issue, NOAA station data.
Links: TIME article, Nature Communications Biology study, natural conditions, resilience of squid populations.
Links: CBC News article, natural wildfires, May 1780 fires, Great Miramichi Fire, long term heat and drought record, burn rate research.
Links: The Denver Post article, Proceedings of the National Academy of
Sciences study, NOAA GHCNd station data.
Links: Fox Valley WI tornado, Wisconsin Examiner story, WI tornado count, Doppler radar, declining tornadoes, Green Bay sounding.
Links: The New York Times article, actual temperature in Paris, Paris UHI, sunshine duration.

Until next month, enjoy these and other great climate fact checks at:

ClimateRealism.com
• False, Phys.org, West Africa’s Heavy Rains Aren’t Unusual or Due to Climate Change
• NPR’s Claim That Climate Change Is Destroying Children’s Summer Fun Is Ridiculous
• Parmesan Cheese Is Not Endangered by Climate Change, Reuters

ClimateDepot.com
• ‘Climate Change is Costing People Sleep’! – ‘Avg person lost nearly 56 hours of sleep per year’ due to ‘hotter nighttime temps’ – Via Climate Central activists
• Celebrate! ’45 Climate Policy Reversals in One Year’ – Climate activists’ lament: ‘I do not think I have ever felt this upset’ – ‘It is worse than it feels’ – ‘It scares me’
• The Editor of UK Telegraph gives up! ‘We’ve lost the war against climate change. Time to scrap net zero’

Wattsupwiththat.com
• Greenland’s Ice Sheet Was Supposed to Be Rapidly Melting Away. It Hasn’t Been.
• Blame Canada’s Terrible Regulations For Wildfires Ruining America’s Summer
• The Great “Hot Drought” Humbug: Why Lake Powell Is Really Drying Up

Read the original PDF, here.

How Aligned Climate Cycles Triggered Droughts That Helped Topple Bronze Age Civilizations

The Late Bronze Age Collapse (roughly 1200–1150 BCE) was a dramatic period when many interconnected civilizations in the Eastern Mediterranean and Near East—such as the Mycenaean palaces in Greece, the Hittite Empire in Anatolia, Ugarit in Syria, and others—experienced widespread disruption, destruction, or decline.

The Late Bronze Age Collapse (roughly 1200–1150 BCE) was a dramatic period when many interconnected civilizations in the Eastern Mediterranean and Near East—such as the Mycenaean palaces in Greece, the Hittite Empire in Anatolia, Ugarit in Syria, and others—experienced widespread disruption, destruction, or decline.

Major powers saw palace economies collapse, trade networks break down, cities get destroyed or abandoned, and populations shift. Egypt survived but faced invasions (e.g., by the “Sea Peoples”), while Assyria endured with contractions. It was not a total “dark age” everywhere but marked the end of the Bronze Age palatial system and a transition toward the Iron Age.

Role of Climate: Not the Sole Cause, But a Major Stressor

Climate change—specifically severe, prolonged droughts (sometimes called a “megadrought”)—is one of the leading factors discussed by researchers. It likely exacerbated other vulnerabilities like economic interdependence, over-reliance on agriculture, political fragility, invasions/migrations (Sea Peoples), possible earthquakes, and social unrest. No single cause explains everything; it was likely a “perfect storm” or systems collapse.

Key evidence for drought:

Pollen records, lake sediments (e.g., Sea of Galilee), speleothems, and tree rings (e.g., juniper in Anatolia) show a shift to drier, more arid conditions around 1250–1100 BCE, one of the driest periods in the Bronze/Iron Age transition.

A particularly acute multi-year drought hit ~1198–1196 BCE (± a few years), coinciding with the Hittite collapse. Tree-ring data from Anatolia indicate unusually low growth, pointing to failed crops and famine.

This aridity affected rain-fed agriculture in the Levant, Anatolia, and Aegean, leading to crop failures, food shortages, and societal strain. River-based systems (Nile, Tigris-Euphrates) were more resilient.

Droughts likely triggered or amplified migrations, resource conflicts, and the breakdown of trade-dependent economies.

Recent Study (2026): Using EC-Earth to “Unravel” the Climate Mechanisms

A new study from Stockholm University (published in Science Advances, July 2026) used the EC-Earth Earth System Model to simulate Mediterranean climate over the past ~8,000 years. It provides deeper insight into why droughts were so severe then.

Main findings:

  • A long-term gradual drying trend over millennia, driven by slow changes in Earth’s orbital parameters (Milankovitch cycles), set the background.
  • Severe droughts (including those around the Late Bronze Age) occurred when multiple shorter-term natural climate cycles aligned and reinforced each other. These involved variations in the Atlantic Ocean (e.g., circulation patterns) and atmospheric dynamics.
  • This “coincidence” pushed the region past a hydroclimatic threshold, causing more intense aridity than the long-term trend alone would suggest. It reduced moisture from African monsoons and shifted rainfall patterns.

The study links these compounded effects to the pressures on agriculture and societies during the collapse period. It notes the Eastern Mediterranean as a climate “hotspot,” with lessons for modern risks: future droughts may depend on how human-caused warming interacts with natural Atlantic variability.

EC-Earth – A European community Earth System Model

EC-Earth is a state-of-the-art Earth System Model (ESM) developed collaboratively by a European consortium of national meteorological services, research institutes, and universities.

It simulates the Earth’s climate system, including interactions between the atmosphere, oceans, land surface, biosphere, cryosphere, and biogeochemical processes. Researchers use it to study climate variability, climate change, feedbacks, and future projections.

Background and Development

  • The consortium started in 2006.
  • It builds on the ECMWF (European Centre for Medium-Range Weather Forecasts) Integrated Forecasting System (IFS), leveraging expertise from weather prediction for climate modeling (the “seamless prediction” concept).
  • EC-Earth has contributed to major international efforts like CMIP5 and especially CMIP6 (Coupled Model Intercomparison Project Phase 6).

EC-Earth3 (the third generation, used for CMIP6) represents a significant advancement over earlier versions, with improved physics, new Earth system components, better performance, and flexible configurations.

_____________________________________________________________________________________

Holocene ocean-atmosphere coupling and Mediterranean sensitivity to Atlantic circulation: Lessons from the Late Bronze Age collapse

“Holocene ocean-atmosphere coupling and Mediterranean sensitivity to Atlantic circulation: Lessons from the Late Bronze Age collapse” is a 2026 paper by Katherine Power (lead author) and colleagues, published in Science Advances (DOI: 10.1126/sciadv.aed5439).

It uses climate modeling to explore long-term Mediterranean climate dynamics and their relevance to the societal stresses during the Late Bronze Age Collapse (~3200 years ago / ~1200 BCE).

Core Approach and Methods

Researchers employed the EC-Earth Earth System Model (a European community model) to simulate Holocene climate evolution (~last 8,000 years). This allowed reconstruction of ocean-atmosphere interactions, precipitation patterns, and drought variability in the Eastern Mediterranean.

The study focuses on:

  • Long-term orbital forcing (slow changes in Earth’s orbit affecting insolation and seasonality).
  • Internal variability, especially in the Atlantic Ocean (e.g., circulation patterns like aspects of the AMOC or related modes) and atmospheric teleconnections.
  • How these interact across timescales to produce hydroclimatic extremes.

Key Findings

The Eastern Mediterranean experienced a gradual drying trend over the Holocene, driven primarily by orbital changes. This created a background of increasing aridity.

Extreme droughts, including those implicated in the Bronze Age period, arose when multiple natural climate cycles (operating on different timescales) aligned in phase. This reinforcement amplified drying far beyond the long-term trend, pushing the region across critical thresholds for water availability.

Processes involved weakening of moisture transport (e.g., from African monsoons) and shifts in atmospheric circulation linked to Atlantic conditions.

This provides a mechanistic explanation for why droughts around the Late Bronze Age were particularly severe and impactful on agriculture-dependent societies.

The paper frames the Late Bronze Age as a case study (“lessons from”) for understanding Mediterranean climate sensitivity. It highlights the region’s vulnerability to compounded natural variability.

Relevance to the Late Bronze Age Collapse

The modeling supports paleoclimate proxy evidence (tree rings, pollen, sediments) of severe aridity ~1250–1100 BCE. It suggests that aligned climate modes contributed to multi-year to multi-decadal droughts, stressing rain-fed agriculture, causing crop failures and famines, and amplifying societal vulnerabilities (trade disruptions, migrations, political instability).

This aligns with but deepens prior work by offering dynamic explanations rather than just describing the droughts.

Broader Implications

Paleoclimate insight:

Demonstrates the importance of ocean-atmosphere coupling and phase relationships in generating extremes, beyond simple external forcing.

Modern relevance:

The Mediterranean is a climate change hotspot. The study implies that future drought risk depends on the interplay between anthropogenic warming and natural Atlantic variability. Understanding these interactions can improve projections of hydroclimatic extremes.

Data and code are likely available via Zenodo (accompanying dataset mentioned in searches).

This is a strong example of interdisciplinary work bridging high-resolution modeling with archaeology and history.

Journal information: Science Advances

DOI: 10.1126/sciadv.aed5439. www.science.org/doi/10.1126/sciadv.aed5439

Provided: Stockholm University

Authors: Katherine Power and Qiong Zhang

Abstract

Climate variability has profoundly influenced societies in the semiarid Eastern Mediterranean. Proxy records indicate progressive mid-Holocene drying culminating in severe droughts ∼1250 BCE, coincident with the Late Bronze Age collapse (1300 to 900 BCE). Using the EC-Earth3-Tr8K transient Holocene simulation, we reconstruct regional hydroclimate evolution and its underlying mechanisms. The model reproduces a gradual orbitally driven aridification, spatially heterogeneous across the region, with persistent drying in the Levant but enhanced effective moisture in parts of the Balkans and Anatolia due to cooling-induced evapotranspiration decline. Superimposed on this long-term trend are extreme drought events, which arise from the alignment of Atlantic internal variability across centennial to millennial timescales, amplifying drying on an already arid background state. These results provide model-based evidence of how evolving amplitude and phase structure of Atlantic internal variability reshaped Eastern Mediterranean hydroclimate through the mid-to-late Holocene. We demonstrate that oceanic variability can manifest as abrupt regional crises when ecological and societal thresholds are crossed.

Climate Fact-Check May 2026

Editor’s note: This compilation serves as a fact check on the top false claims made about climate change by the media in May 2026.

Debunking claims of climate causing ‘less healthy’ food – Melting ice will NOT ‘drown millions’ – Droughts NOT caused by fossil fuels – Earth is NOT spinning slower due to climate change!

From ClimateRealism

Guest Post by: The Committee for a Constructive Tomorrow, The Heartland Institute, the Competitive Enterprise Institute, the Energy & Environmental Legal Institute, and the International Climate Science Coalition, and Truth in Energy and Climate.

Editor’s note: This compilation serves as a fact check on the top false claims made about climate change by the media in May 2026.

Debunking claims of climate causing ‘less healthy’ food – Melting ice will NOT ‘drown millions’ – Droughts NOT caused by fossil fuels – Earth is NOT spinning slower due to climate change!

Links: The Washington Post article, Leiden University analysis, examples of experiments, Free-Air carbon dioxide enrichment, crop yield increases.
Links: Committee animation, U.S. drought monitor, drought classification, NOAA climate definition.
Links: The Daily Mail post, Nature study, East Antarctica ice gains, IPCC AR6.
Links: IPCC abandoning high-end scenarios, The Washington Post article, The New Republic article, plausibility, coal consumption estimate, proven reserves.
Links: Climate Central report, UHI mapping, paper on UHI.
Links: BBC article, JGR Solid Earth study, frictional effects, El Niño–Southern Oscillation.

Until next month, enjoy these and other great climate fact checks at:

ClimateRealism.com

ClimateDepot.com

Wattsupwiththat.com

Quit Fearmongering, San Francisco Chronicle, Climate Change Isn’t Coming for Cabernet

The San Francisco Chronicle posted an article claiming that climate change is harming Cabernet production, specifically in California. This is false. The climate hasn’t appreciably changed for the worse in California amid modest warming. Wildfires are not outside of their historical norm and droughts haven’t become more frequent or severe.

From ClimateRealism


By H. Sterling Burnett

The San Francisco Chronicle posted an article claiming that climate change is harming Cabernet production, specifically in California. This is false. The climate hasn’t appreciably changed for the worse in California amid modest warming. Wildfires are not outside of their historical norm and droughts haven’t become more frequent or severe. Data show fluctuations in Cabernet production across the decades, but no sustained downward trend correlating to global warming or carbon dioxide emissions. In fact, the highest production years for cabernet grape tonnage have all occurred during twenty-first century, supposedly the hottest years on record.

In the story, “Climate change is coming for Cabernet. Here’s how one Napa winery is getting ready,” staff writer, Jess Lander, writes:

In 2019, the greatest threat to California wine was climate change. It felt like a reckoning was coming, especially to Napa Valley, where the future of its crown jewel grape, Cabernet Sauvignon . . ..

Then, suddenly, winemakers stopped talking so much about climate change.

COVID-19 hit in 2020, forcing wineries to close to visitors and find new ways to reach customers. (Remember virtual tastings?) A few months later, more than 30 Napa Valley wineries were damaged or destroyed in devastating wildfires, and smoke from the disasters nearly wiped out an entire vintage. Starting in late 2022, California wine began to feel the effects of an unprecedented downturn in the wine industry. Ever since, California wineries have been in survival mode, battling a litany of challenges, including declining sales and tourism; a major grape oversupply; competition from alternative alcoholic beverages, like seltzers and ready-to-drink cocktails; tariffs and the loss of the Canadian export market; and growing anti-alcohol sentiment among Americans.

In truth, there is no evidence that climate change has ever posed a threat to California or Napa Valley Cabernet production.

Neither drought nor wildfire in California are outside of their normal frequency or severity. Since European colonization of America and migration to California, severe droughts were recorded in 1841, 1864, 1895, 1924, 1928–1935, 1947–1950, 1959–1961, 1976–1977, 1986–1992, 2007–2009, and 2011–2017,2020–2022 and 2024-25. Many of those droughts occurred long before human greenhouse gas emissions rose significantly, when the Earth was cooler. Indeed, historic droughts in California were much more lengthy and severe. Even with the recent droughts, the past two centuries have been relatively wet when compared to California’s historic drought patterns, as seen in the graphic below.

Dozens of Climate Realism posts provide data and reference peer-reviewed studies showing wildfire frequency and severity in California are well below historic norms, even with a small uptick in recent years due to shifts in land management and increasing urban expansion into areas historically prone to wildfires, here, here, here, and here, for instance.

If drought and wildfires haven’t become more common or severe as the climate has undergone a modest change, then that change can’t be behind any Cabernet grape production losses. Even more telling is the fact that Cabernet production is, contrary to what is implied by Lander’s San Francisco Chronicle story, doing well amid modest climate change.

Interestingly, in 2019, seven years ago, CBS News warned “Climate change is coming for your Cabernet,” almost the same title as the San Francisco Chronicle story. Yet just four years later, data from the Wine Institute show that California’s Cabernet production was the state’s second highest on record, with the record being set just the year before CBS bemoaned Cabernet’s supposed fate. Indeed, despite some vineyards closing, resulting in acreage taken out of production and modest warming, no year’s production since 2010 has been lower than any year’s production before then. No year after 2000 experienced Cabernet crushed grape tonnage lower than any year before then. As the graphic below shows, with fits and starts due to normal agricultural ups and downs, California’s Cabernet production has increased dramatically. California’s all-time record for Cabernet production was set in 2018, with 2023 being the second highest production year on record.

Nor, despite the San Francisco Chronicle’s warnings of a climate change induced Cabernet apocalypse, does the industry seem to believe Cabernet production is doomed due to climate change or any other factor, like reduced wine consumption or rising costs amidst falling prices. In fact, ReNub writes concerning the future market for conditions for Cabernet, “[c]abernet Sauvignon Market is expected to reach US$ 789.98 Million by 2034 from US$ 362.23 Million in 2025, with a CAGR [compound annual growth rate] of 9.05% from 2026 to 2034.” (See the image)

Cabernet may face some serious headwinds, but they have nothing to do with climate change. As mentioned, but downplayed in Lander’s article, trade issues, a decline in alcohol consumption among younger demographics, and higher input costs, are among the factors squeezing vintner’s profits. In France, as discussed at Climate Realism here and here, they have a solution, blame climate change for wine’s woes, while pouring excess wine down the drain rather than put it on the market. The problem is a glut of wine suppressing prices, not a surfeit.

The article, “Climate change is coming for Cabernet. Here’s how one Napa winery is getting ready,” is a disservice to the San Francisco Chronicle’s readers, misrepresenting the true state of Cabernet production and its prospects in an attempt to advance the false narrative that climate change is dooming the world, one product, crop, or industry at a time.

NYT goes full witchcraft, cites an academic declaring Trump will cause bad weather!

In recent days his administration has slammed the door on every possible avenue of global cooperation on the environment. At the same time, it is sending the message that it wants the world to be awash in fossil fuels sold by America, no matter the consequences.

A man holding a black umbrella stands against a backdrop of a stormy New York City skyline, featuring tall buildings and a cloudy sky.

From The Climate Depot

By Admin

A person holding a black umbrella standing on a wet city street during rain, with blurred cars and buildings in the background.

Under Trump, U.S. Adds Fuel to a Heating Planet – The New York Times

Excerpt:

In recent days his administration has slammed the door on every possible avenue of global cooperation on the environment. At the same time, it is sending the message that it wants the world to be awash in fossil fuels sold by America, no matter the consequences.

Under President Trump, the United States has become the only nation to renege on a pledge to try to keep warming to 1.5 degrees. Its actions will make the global fight harder, scientists said.

“Emissions will be higher,” warned Justin S. Mankin, an associate professor at Dartmouth College who researches climate variability. “Trump’s greenhouse gas emissions will cause Trump’s heat waves, Trump’s droughts, Trump’s floods, and Trump’s wildfires.”

…

“The science is clear that every action matters and every ton of carbon matters,” said Katharine Hayhoe, a climate scientist and professor at Texas Tech. “There’s a price to pay for every ton of carbon we produce, and that price is being added to our global debt.”

Quote from Justin S. Mankin, associate professor at Dartmouth College, discussing the impact of greenhouse gas emissions on climate variability.

#

Blaming bad weather/hurricanes on Trump and/or ‘global warming’ is a throwback to medieval witchcraft – Book Excerpt –

Have We Advanced since the Middle Ages?

Did you know?

Witch hunts increased during the Little Ice Age
The Aztecs had one advantage over our climate experts—they realized the sun was responsible for global warming
A University of Cincinnati professor blamed the rise of Hitler on global warming.

Princeton Professor Emeritus of Physics William Happer in 2017 drew parallels to today’s man-made climate change claims. “I don’t see a whole lot of difference between the consensus on climate change and the consensus on witches. At the witch trials in Salem the judges were educated at Harvard. This was supposedly 100 per cent science. The one or two people who said there were no witches were immediately hung. Not much has changed,” Happer quipped.

[Note: According to The Salem Witch Trial judges: “Five of the nine judges had attended Harvard, though only William Stoughton, Samuel Sewall and Nathaniel Saltonstall had graduated.” — On 27 May 1692, Sir William Phips, the newly appointed royal governor of the Massachusetts Bay Colony, appointed nine of the colony’s leading magistrates to serve as judges for the newly created Court of Oyer and Terminer. When Phips sailed into Boston from London on 14 May, there were already 38 people in jail for witchcraft, and the accusations and arrests were growing daily. One of the governor’s first official acts was to create this special court to deal with the growing crisis…Governor Phips carefully chose men he described as “persons of the best prudence.”… All nine were members of the Governor’s Council, and most of them had served as judges for many years. Many had even been on panels that had heard previous witchcraft cases.]