LA REVUE GAUCHE - Left Comment

Friday, November 26, 2021

Were the ancient Maya an agricultural cautionary tale? Maybe not, new study suggests

Many believe climate change and environmental degradation caused the Maya civilization to fall—but a new survey shows that some Maya kingdoms had sustainable agricultural practices and high food yields for centuries.

For years, experts in climate science and ecology have held up the agricultural practices of the ancient Maya as prime examples of what not to do.

"There's a narrative that depicts the Maya as people who engaged in unchecked agricultural development," said Andrew Scherer, an associate professor of anthropology at Brown University. "The narrative goes: The population grew too large, the agriculture scaled up, and then everything fell apart."

But a new study, authored by Scherer, students at Brown and scholars at other institutions, suggests that that narrative doesn't tell the full story.

Using drones and lidar, a remote sensing technology, a team led by Scherer and Charles Golden of Brandeis University surveyed a small area in the Western Maya Lowlands situated at today's border between Mexico and Guatemala. Scherer's lidar survey—and, later, boots-on-the-ground surveying—revealed extensive systems of sophisticated irrigation and terracing in and outside the region's towns, but no huge population booms to match. The findings demonstrate that between 350 and 900 A.D., some Maya kingdoms were living comfortably, with sustainable agricultural systems and no demonstrated food insecurity.

"It's exciting to talk about the really large populations that the Maya maintained in some places; to survive for so long with such density was a testament to their technological accomplishments," Scherer said. "But it's important to understand that that narrative doesn't translate across the whole of the Maya region. People weren't always living cheek to jowl. Some areas that had potential for agricultural development were never even occupied."

The research group's findings were published in the journal Remote Sensing.

When Scherer's team embarked on the lidar survey, they weren't necessarily attempting to debunk long-held assumptions about Maya agricultural practices. Rather, their primary motivation was to learn more about the infrastructure of a relatively understudied region. While some parts of the western Maya area are well studied, such as the well-known site of Palenque, others are less understood, owing to the dense tropical canopy that has long hidden ancient communities from view. It wasn't until 2019, in fact, that Scherer and colleagues uncovered the kingdom of Sak T'zi," which archeologists had been trying to find for decades.

The team chose to survey a rectangle of land connecting three Maya kingdoms: Piedras Negras, La Mar and Sak Tz'i," whose political capital was centered on the archeological site of Lacanjá Tzeltal. Despite being roughly 15 miles away from one another as the crow flies, these three urban centers had very different population sizes and governing power, Scherer said.

"Today, the world has hundreds of different nation-states, but they're not really each other's equals in terms of the leverage they have in the geopolitical landscape," Scherer said. "This is what we see in the Maya empire as well."

Scherer explained that all three kingdoms were governed by an ajaw, or a lord—positioning them as equals, in theory. But Piedras Negras, the largest kingdom, was led by a k'uhul ajaw, a "holy lord," a special honorific not claimed by the lords of La Mar and Sak Tz'i." La Mar and Sak Tz'i' weren't exactly equal peers, either: While La Mar was much more populous than the Sak T'zi' capital Lacanjá Tzeltal, the latter was more independent, often switching alliances and never appearing to be subordinate to other kingdoms, suggesting it had greater political autonomy.

The lidar survey showed that despite their differences, these three kingdoms boasted one major similarity: Agriculture that yielded a food surplus.

"What we found in the lidar survey points to strategic thinking on the Maya's part in this area," Scherer said. "We saw evidence of long-term agricultural infrastructure in an area with relatively low population density—suggesting that they didn't create some crop fields late in the game as a last-ditch attempt to increase yields, but rather that they thought a few steps ahead."

In all three kingdoms, the lidar revealed signs of what the researchers call "agricultural intensification"—the modification of land to increase the volume and predictability of crop yields. Agricultural intensification methods in these Maya kingdoms, where the primary crop was maize, included building terraces and creating water management systems with dams and channeled fields. Penetrating through the often-dense jungle, the lidar showed evidence of extensive terracing and expansive irrigation channels across the region, suggesting that these kingdoms were not only prepared for population growth but also likely saw food surpluses every year.

"It suggests that by the late Classic Period, around 600 to 800 A.D., the area's farmers were producing more food than they were consuming," Scherer said. "It's likely that much of the surplus food was sold at urban marketplaces, both as produce and as part of prepared foods like tamales and gruel, and used to pay tribute, a tax of sorts, to local lords."

Scherer said he hopes the study provides scholars with a more nuanced view of the ancient Maya—and perhaps even offers inspiration for members of the modern-day agricultural sector who are looking for sustainable ways to grow food for an ever-growing global population. Today, he said, significant parts of the region are being cleared for cattle ranching and palm oil plantations. But in areas where people still raise corn and other crops, they report that they have three harvests a year—and it's likely that those high yields may be due in part to the channeling and other modifications that the ancient Maya made to the landscape.

"In conversations about contemporary climate or ecological crises, the Maya are often brought up as a cautionary tale: "They screwed up; we don't want to repeat their mistakes,'" Scherer said. "But maybe the Maya were more forward-thinking than we give them credit for. Our survey shows there's a good argument to be made that their agricultural practices were very much sustainable."In Guatemala, archaeologists uncover hidden neighborhood in ancient Maya city

More information: Charles Golden et al, Airborne Lidar Survey, Density-Based Clustering, and Ancient Maya Settlement in the Upper Usumacinta River Region of Mexico and Guatemala, Remote Sensing (2021). DOI: 10.3390/rs13204109

Provided by Brown University

Skull found on Caribbean island shows evidence of leprosy

by University of Oregon

A skull unearthed on an uninhabited Caribbean island is a rare find: It's one of just a few examples of leprosy identified on a skeleton in the western hemisphere.

And it's the only one that's been directly dated using radiocarbon, by analyzing a fragment of the skull itself rather than estimating an age using nearby artifacts or materials. The bones are from the late 18th or early 19th century, reports a team led by UO archaeologist Scott Fitzpatrick.

Fitzpatrick's team, which also included lead author and skeletal biologist Greg Nelson and former UO honors student Taylor Dodrill, detailed their findings in a paper published online Nov. 13 in the International Journal of Paleopathology.

The specimen was found on Petite Mustique, a rugged uninhabited island. Historical records suggest that the island might have been the site of a leprosarium in the early 1800s, when people with leprosy could be isolated to prevent spread of disease.

"There are a number of pretty well-known cases in the Caribbean and Pacific where smaller islands were used as places to segregate people with leprosy, such as Molokai in Hawaii," said Fitzpatrick, who is also the associate director for research at the Museum of Natural and Cultural History.

But while leprosy has been documented in the Caribbean via written evidence beginning around the mid-17th century, those reports have been incomplete. Archaeologists have found scant skeletal evidence of the disease that could help trace its pattern of spread. This new find adds to that picture.

Leprosy causes dramatic disfigurement of the hands, feet and face, and those changes show up in bones. Nelson determined that the person had leprosy based on the pattern of skeletal deformation in the nose and upper jaw of the skull.

The disease spreads through prolonged close contact with someone who is sick, but "the fact that leprosy can also lead to noticeable disfigurement of the hands, feet and particularly the face made it a very scary disease and likely precipitated moves to isolate people with leprosy," Nelson said.Leprosy confirmed in wild chimpanzees

More information: Greg C. Nelson et al, A probable case of leprosy from colonial period St. Vincent and the Grenadines, Southeastern Caribbean, International Journal of Paleopathology (2021). DOI: 10.1016/j.ijpp.2021.10.004

Provided by University of Oregon

Genetic changes in Bronze Age Southern Iberia

by Autonomous University of Barcelona

The third millennium BCE is a highly dynamic period in the prehistory of Europe and western Asia, characterized by large-scale social and political changes. In the Iberian Peninsula, the Copper Age was in full swing in around 2500 years BCE with substantial demographic growth, attested by a large diversity of settlements and fortifications, monumental funerary structures, as well as ditched mega-sites larger than 100 hectares. For reasons that are still unclear, the latter half of the millennium experienced depopulation and the abandonment of the mega-sites, fortified settlements and necropolis.

In southeastern Iberia, one of the most outstanding archaeological entities of the European Bronze Age emerged around 2200 BCE. Known as the El Argar culture, one of the first state-level societies on the European continent, it was characterized by large, central hilltop settlements, distinct pottery, specialized weapons and bronze, silver and gold artifacts, alongside an intramural burial rite.

A new study led by researchers from the Universitat Autònoma de Barcelona and the Max Planck Institutes for the Science of Human History (Jena) and Evolutionary Anthropology (Leipzig) and published in Science Advances, explores the relation between dynamic shifts at population scale and the major social and political changes of the third and second millennia BCE by analyzing the genomes of 136 ancient Iberians, ranging from 3000 to 1500 BCE.

Genetic turnover and melting pot

Including published genomes from Iberia, the new study encompasses data from nearly 300 ancient individuals and focuses specifically on the Copper to Bronze Age transition around 2200 BCE.

"While we knew that the so-called 'steppe'-related ancestry, which had spread across Europe during the third millennium BCE, eventually reached the northern Iberian Peninsula around 2400 BCE, we were surprised to see that all prehistoric individuals from the El Argar period carried a portion of this ancestry, while the Chalcolithic individuals did not," says Max Planck researcher Wolfgang Haak, senior author and principal investigator of the study.

The genomic data reveals some of the processes underlying this genetic shift. While the bulk of the genome shows that Bronze Age individuals are a mix of local Iberian Chalcolithic ancestry and a smaller part of incoming ancestry from the European mainland, the paternally inherited Y chromosome lineages show a complete turnover, linked to the movement of steppe-related ancestry that is also visible in other parts of Europe.

The rich new data from the El Argar sites also show that these two components do not fully account for the genetic make-up of the early Bronze Age societies. "The causes of this disappearance of the previous diversity of the Y chromosome are still very difficult to explain," says Cristina Rihuete Herrada, UAB researcher and co-author of the study.

"We also found signals of ancestry that we traced to the central and eastern Mediterranean and western Asia. We cannot say exactly whether these influences arrived at the same time as the steppe-related ancestry, but it shows that it formed an integrative part of the rising El Argar societies, attesting to continued contacts to these regions," adds Vanessa Villalba-Mouco, postdoctoral researcher and lead author of the study.

UAB researchers already pointed to possible Mediterranean connections when they discovered in 2013 the monumental fortification of the Argaric settlement of La Bastida, in Murcia, to explain the originality of some architectural elements. "The genetic study argues in favor of this hypothesis: the data show that this unknown Mediterranean connection would have been sustained over time until the end of the period of El Argar, around 1500 BCE," says Rafael Micó, UAB researcher and co-author of the study.

Social implications

"Whether the genetic shift was brought about by migrating groups from North and Central Iberia or by climatic deteriorations that affected the eastern Mediterranean around 2200 BCE is the million-dollar question," says co-principal investigator and senior author Prof Roberto Risch from the Universitat Autònoma de Barcelona. "It would be foolish to think that it can all be explained by a simple, one-factor model. While the temporal coincidence is striking, it is likely that many factors played a role."

One of these factors could be pandemics, such as an early form of the Plague, which has been attested to in other regions of Europe around that time. While not found directly among the tested individuals in southern Iberia, it could be a cause or driver for the movement or disappearance of other groups in the region.

"In any case, we can now conclude that the population movement starting in the eastern European steppe zones around 3000 BCE was not a single migratory event, but required over four centuries to reach the Iberian Peninsula and another 200 years to appear in present-day Murcia and Alicante," adds Risch.

The archaeological record of the El Argar group shows a clear break with previous Chalcolithic traditions. Burial rites, for example, changed from communal to single and double burials within the building complexes. Elite burials also indicate the formation of strong social hierarchies. Testing for biological relatedness, the researchers found that males are on average more closely related to other people at the site, indicating that the group was likely patrilineally structured. Such a social organization could explain the stark reduction of the Y-lineage diversity.

"We observe similar patterns of social organization and increasing stratification also in other parts of Early Bronze Age Europe, in fact broadly around the same time and with similar characteristics of early state-like formations. This suggests a structured restart or resetting following some form of crisis or unstable, highly dynamic times," summarizes Haak.

In the research have participated, among others, these institutions: Adelaide University, Danube Private University, Basel University, Fundación Vasca para la Ciencia, Universidad de Valencia, Cape Town University, Universidad de Alicante, Museo Arqueológico de Alicante, Museo Arqueológico Municipal de Lorca, Universidad de Murcia, Harvard Medical School, Harvard University, Howard Hughes Medical Institute y Universidad de Sevilla.

Central European prehistory was highly dynamic

More information: Vanessa Villalba-Mouco et al, Genomic transformation and social organization during the Copper Age-Bronze Age transition in southern Iberia, Science Advances (2021). DOI: 10.1126/sciadv.abi7038. www.science.org/doi/10.1126/sciadv.abi7038

Journal information: Science Advances

Provided by Autonomous University of Barcelona

The world's oldest mercury poisoning revealed in Copper Age Iberia

by University of Seville

The World Health Organization (WHO) states that exposure to mercury, a natural element that can be present in the air, water and soil, can cause serious health problems, even in small amounts. Mercury contamination or poisoning can have serious toxic effects on humans, affecting the nervous, digestive, and immune systems, as well as the lungs, kidneys, skin, and eyes. The WHO currently considers mercury to be one of the top ten substances of greatest public health concern.

A recent paper published in the International Journal of Osteoarchaeology and in which researchers from the University of Seville participate, explores the complex relationship between humans and mercury over time. In this article, titled "The use and abuse of cinnabar in Late Neolithic and Copper Age Iberia," a team of 14 specialists in biology, chemistry, physical anthropology and archaeology have presented the results of the largest study ever carried out on the presence of mercury in human bone, with a sample of a total of 370 individuals from 50 tombs located in 23 archaeological sites in Spain and Portugal dating from Neolithic, Copper Age, Bronze Age and antiquity, thus encompassing 5,000 years of human history.

The results reveal that the highest levels of mercury exposure occurred at the beginning of the Copper Age, between 2900 and 2600 BC. In this period, the exploitation and use of cinnabar increased considerably for social and cultural reasons. Cinnabar (HgS) is a mercury sulfide mineral that, when pulverized, turns into a powder of a striking and brilliant red color. Historically, this substance has been used to produce pigments in paint, being famous already in antiquity ("Pompeian red") or in modern art (known as "vermilion"). It so happens that the largest cinnabar mine in the world, declared a World Heritage Site by UNESCO, is located in Almadén, in central Spain).

The exploitation of the Almadén cinnabar began in the Neolithic, 7,000 years ago. By the beginning of the Copper Age, around 5000 years ago, cinnabar became a product of great social value, with a character that was both sacred, esoteric and sumptuous. In tombs from this period discovered in southern Portugal and Andalusia, cinnabar powder (often turned into a pigment) was used to paint megalithic chambers, decorate figurines or stelae, and to spread it over the dead. As a result, many people must have accidentally inhaled or consumed it, leading to unsuspected accumulations of mercury in their bodies. Levels of up to 400 parts per million (ppm) have been recorded in the bones of some of these individuals. Taking into account that the WHO currently considers that the normal level of mercury in hair should not be higher than 1 or 2 ppm, the data obtained reveal a high level of intoxication that must have severely affected the health of many of those people. In fact, the levels detected in some subjects are so high that the study authors do not rule out that cinnabar powder was deliberately consumed, by inhalation of vapors, or even ingestion, for the ritual, symbolic and esoteric value that was attributed to it.

The results of this study provide scientific evidence of great value to expand future research on the complex relationship of human beings with mercury, one of the most peculiar mineral substances on our planet, and to learn about its uses and their consequences for human health.Fish consumption still safe despite initial fears over mercury levels

More information: Steven D. Emslie et al, The Use and Abuse of Cinnabar in Late Neolithic and Copper Age Iberia, International Journal of Osteoarchaeology (2021). DOI: 10.1002/oa.3056

Provided by University of Seville

Easternmost Roman aqueduct discovered in Armenia

by University of Münster

Archaeologists from the University of Münster and the National Academy of Sciences of the Republic of Armenia have discovered remains of a Roman arched aqueduct during excavation work on the Hellenistic royal city of Artashat-Artaxata in ancient Armenia. It is the easternmost arched aqueduct in the Roman Empire. Excavation work took place back in 2019, and an evaluation of the find has now been published in the Archäologischer Anzeiger journal.

"The monumental foundations are evidence of an unfinished aqueduct bridge built by the Roman army between 114 and 117 CE," explains author Prof. Achim Lichtenberger from the Institute of Classical Archaeology and Christian Archaeology at the University of Münster. "At that time, Artaxata was destined to become the capital of a Roman province in Armenia." It was during this time that the Roman Empire reached its greatest extent—if only for a short while—because it was under Trajan, who was Emperor of Rome from 98 to 117 CE—that the Romans attempted to incorporate the province of Armenia into the Roman Empire. "The planned, and partially completed, construction of the aqueduct in Artaxata shows just how much effort was made, in a very short space of time, to integrate the infrastructure of the capital of the province into the Empire," says co-author Torben Schreiber from the Institute of Classical Archaeology and Christian Archaeology at the University of Münster. "The aqueduct remained unfinished because after Trajan's death, in 117 CE, his successor Hadrian relinquished the province of Armenia before the aqueduct was completed." The archaeologists therefore see their find as furnishing evidence for the failure of Roman imperialism in Armenia.

Methods

In their excavation campaign, the team used a multidisciplinary combination of methods from the fields of archaeology, geophysics, geochemistry and archaeoinformatics. The area of the Hellenistic metropolis of Artaxata in the Ararat Plain was first examined geomagnetically. At this stage of their work, the experts surveyed and charted any anomalies. The geomagnetic image showed a conspicuous dotted line, which they analyzed with so-called sondages. The results were documented by the archaeologists three-dimensionally. Additional drillings provided evidence of further unfinished or destroyed pillars of the aqueduct. "We used satellite pictures and infrared images from a drone to visualize the course of the aqueduct's pillars," says co-author Dr. Mkrtich Zardaryan from the Institute of Archaeology and Ethnography at the National Academy of Sciences of the Republic of Armenia. "We reconstructed the planned course of the aqueduct by means of a computer-assisted path analysis between the possible sources of the water and its destination." A scientific analysis of the lime mortar used showed that it was a typical Roman recipe. An analysis of soil samples dated the construction of the aqueduct to between 60 and 460 CE, and in the opinion of the researchers this makes the reign of Emperor Trajan the most likely dating for it.

Project: "Artaxata in Armenia—Fieldwork in a Hellenistic Metropolis in the Ararat Plain"

Since 2018 a team of German and Armenian scientists—headed by Achim Lichtenberger (Münster University), Mkrtich Zardaryan (Armenian Academy of Sciences) and Torben Schreiber (Münster University) – have been carrying out research into the Hellenistic metropolis of Artaxata in the Ararat Plain in Armenia. Their aim is to examine both a newly established Hellenistic royal city and the many-faceted cultural imprint between Central Asia, Iran and the Mediterranean region.The Aqueduct of Constantinople: Managing the longest water channel of the ancient world

More information: A. Lichtenberger et al, An Unfinished Roman Aqueduct at Artaxata in Armenia, Archäologischer Anzeiger 2021. doi.org/10.34780/8f82-fyw2

Provided by University of Münster

Australia's coal country looks to a less sooty future

by Andrew Leeson

Australia's conservative government has boasted it will sell coal for as long as anyone is buying — Australia's conservative government has boasted it will sell coal for as long as anyone is

Australia's conservative leaders have defied calls for urgent climate action, boasting they will sell coal for as long as anyone is buying. But in the country's carbon heartland, locals are already preparing for life beyond fossil fuels.

Two-hundred-and-thirty years ago, among the verdant outcrops that flank the southeastern coastal town of Newcastle, a band of escaped convicts made the first recorded discovery of coal on the Australian continent.

It would begin Australia's long love affair with the sooty fuel that now nets the country tens of billions of dollars a year and has made Newcastle the world's largest coal-exporting port.

Nathan Clements was born and raised in the nearby town of Singleton, which he described as "very much the heartland of coal mining here".

"I don't want to say coal is everything, but it's a lot," he said.

"My older brother worked in a coal mine, my dad worked in a mine and still does to this day. When it was my turn, it was the norm to walk into that industry," said the 26-year-old, who for the last seven years has worked as an electrical fitter fixing mine equipment.

Around Singleton and the broader Hunter region, evidence of the vast scale of the coal industry is obvious.

Coal trains rumble through the countryside, each engine dragging a writhing column of rusty wagons from far into the distance.

In Australia's coal heartland, however, locals are already preparing for life beyond fossil fuels.

From the air, open cast mines pock the bush with jet-black scars. Off the coast, an armada of vessels waits, ready to load up and return to China, India, Japan or South Korea with mountains of millennia-old rock.

And Australia's government would like to keep it that way.

When dozens of countries, meeting at COP26 talks in Glasgow, recently agreed to phase out coal, Australia baulked.

"We are not closing coal mines and we are not closing coal-fired power stations," said resource minister Keith Pitt, using the opportunity to boast about the quality of Australian coal and 300,000 Australian jobs linked to the sector.

'A change in attitudes'

But unlike the government, workers in Singleton and towns across the Hunter are gradually coming to terms with King Coal's demise.

"I still need to work. I still need a job," said Clements, but "it is inevitable. There is an inevitability to it."

Coal nets Australia billions of dollars a year.

For him, there was a slow realisation that he might not be able to follow the career path of his father, who will retire in his coal job next year when Muswellbrook—Australia's oldest open cut coal mine—closes after almost 115 years of operation.

Clements said discussing the industry's future has become markedly less taboo and scepticism more mainstream with catastrophic events of the last few years.

"For a lot of people, I noticed a change in attitudes around the 2019-2020 bushfires," he said, referring to the climate-worsened disaster that tore through much of southeastern Australia.

And despite the government's bravado, the market is voting with its feet.

The very largest mining firms, such as Australia's own BHP and Rio Tinto, are already sprinting for the exits, rapidly offloading coal assets to smaller risk-embracing outfits.

Official figures show the number of people directly employed in the coal industry is more like 44,600—less than half the number of Australians employed by McDonald's.

Some in the coal sector are fearful that well-paying jobs are going to quickly become a thing of the past.

Newcastle in Australia is the world's largest coal-exporting port.

No silver bullet

But others are optimistic that their region will succeed despite Canberra's digging in on a seemingly dying industry.

"There's so much innovation going on," said Sam Mella of Beyond Zero Emissions, a think tank working with local industry on diversification.

She pointed to the infrastructure around coal—the port, the rail network, transmission lines as well as universities and research institutes—as a valuable asset for the region.

"We have this fantastic legacy to build on," she said. "I think the Hunter is going to lead the way in the post-carbon economy."

So far, there is no silver bullet—no one technology or project that will save the entire region or replace coal.

But there is hope that out of the plethora of projects, from water filtration technology to megawatt-scale batteries to designing and manufacturing hyper-efficient wind turbines, that something will emerge.

The question is whether the transition can come quickly enough for workers like Clements.

"My concern is that when the market finally says 'nah, we're not interested anymore' that we don't have a plan, and a lot of people lose their jobs."

But "I think there is still a chance for the region, I don't think it's a one-way ticket," he said. "There is definitely still a bit of life there."Australia vows to keep mining coal despite climate warning

Syria reservoir dries up for first time

A rowing boat lies grounded on the exposed lake bed of Syria's Duwaysat Dam reservoir after it dried up completely for the first — A rowing boat lies grounded on the exposed lake bed of Syria's Duwaysat Dam reservoir

Low rainfall, structural damage and extraction by struggling farmers have emptied a key reservoir in northwestern Syria, leaving it completely dry for the first time, farmers and officials told AFP.

With man-made climate change increasing the frequency of drought and wildfires worldwide, Syria is experiencing one of its driest and hottest years on record after historically low rainfall last winter.

The reservoir formed by Al-Duwaysat Dam in Idlib province, a key irrigation source for thousands of farmers, has completely dried up for the first time in its 27-year history.

The exposed lake bed is parched to a crisp in many places, a sinister expanse littered with stranded rowing boats, animal skulls and dead trees.

A few shallow pools remain, around which small flocks of sheep graze on new shoots.

According to the World Bank, the reservoir has a capacity of a 3.6 million cubic metres (38.8 million square feet) and is mainly used for irrigation and water supply.

"Because of drought and low rainfall, we can now walk on the floor of the reservoir," its managing engineer Maher al-Hussein said, recalling that it was full to capacity just two years ago.

Low rainfall last winter left the reservoir half-full and all the water was used for irrigation by farmers trying to save their crops, Hussein said.

A shepherd waters his flock from the small pools that are that are all that is left of the reservoir following successive years — A shepherd waters his flock from the small pools that are that are all that is left of the

Damage to the main pipeline that feeds water from the reservoir to irrigation networks has led to significant leakages, further reducing the volume that reaches the fields, he added.

"It is the first time the reservoir has dried out since it was built in 1994," Hussein said.

He said around 800 families depended on the reservoir to irrigate 150 hectares (370 acres) of farmland.

"For 10 years we have come to this reservoir," said cattle farmer Abu Joumaa. "If God does not send us good rainfall that could fill the reservoir this year... people won't be able to grow crops they rely on to make a living."

Colorado basin drought sparks water limits at huge US reservoir

New stress test model quantifies climate risks for banks

by Technical University Munich

European banks will soon be required to incorporate climate change risks into the stress testing of their equity. Researchers at the Technical University of Munich (TUM) have now developed a new approach in cooperation with the Frankfurt Institute for Risk Management and Regulation (FIRM). In a case study they applied their stress testing method in several CO2 pricing scenarios. Due to sharp rises in probabilities of credit default in several industries, the results show that the bank in question would face significant decreases in capital ratios. The model can help banks to prepare for future risks.

Climate change can cause substantial losses to companies, not only as a direct result of extreme weather events, but also through transitory risks, above all in the form of rising CO2 prices and long-term decreases in economic value creation. This, in turn, means greater risks for banks if companies are unable to service loans. Consequently, the European Central Bank (ECB) and the European Banking Authority (EBA) have ordered financial institutions to incorporate climate risks into their risk management and stress testing processes, which serve primarily to evaluate their capital buffers. The new requirement will take effect in 2022.

It is still unclear, however, how this requirement can be implemented. Nor is it certain what dimensions the transitory climate risks might reach in stress tests. Researchers at the Technical University of Munich (TUM) have therefore worked with the Frankfurt Institute for Risk Management and Regulation (FIRM) to develop a method that can be adapted to a variety of stress tests and have applied it in two case studies involving a bank and two investment funds.

Case study with 400 Euro STOXX companies

The model is based on a definition of transitory climate risks derived from recognized forecasts such as the Shared Socioeconomic Pathways (SSP), the resulting macroeconomic analysis for states and industries, and companies' CO2 footprints. On that basis, the research team investigated around 400 companies listed in the Euro STOXX 600 index. They looked at four scenarios distinguished by different CO2 pricing levels (50 or 100 euros per ton), the potential of companies to reduce CO2 emissions and the share of costs passed through to consumers. All of the scenarios assume an abrupt introduction of a CO2 tax.

Sectors with probabilities of default of 5–34 percent

The analysis shows that in every scenario around 10 percent of the investigated companies would face asset devaluations of more than 15 percent. In the most adverse scenario, 6 percent of the companies would see their assets devalued by over 30 percent. On a industry-by-industry basis, the assets of the six hardest-hit sectors would devaluate by 15–36 percent.

With these results, the researchers carried out a stress test on a major European bank. They began by calculating the rise in companies' probabilities of credit default caused by the loss in asset values. In the most adverse scenario, 16 percent of the companies would have a probability of default of over 3 percent, which is considered high risk. The six most adversely affected sectors would have probabilities of default ranging from about 5 percent to 34 percent. Based on the bank's so-called risk-weighted assets in relation to these corporate loans, the researchers calculated the effects on the bank's equity.

Total capital ratio reduced by up to 1.56 percentage points

The stress test shows that across all scenarios, the bank's common equity Tier 1 (CET1) capital would decrease by between 0.1 and 1.2 percentage points. The core capital ratio (Tier 1) would be down by 0.1–1.3 percentage points and the total capital ratio by 0.2–1.6 percentage points. By comparison: the average core capital ratio of European banks was 15 percent at the end of 2020, so that the scenarios analyzed by the researchers would mean decreases of between 1 percent and nearly 10 percent.

"The stress test underscores the fact that transitory climate risks could pose a major challenge to the stability of the financial sector if no measures are taken," says study author Gunther Friedl, professor of management accounting at TUM. "Our models and assumptions are undoubtedly quite strict—but that is the point of a stress test. Climate change may cause such severe asset losses and high-risk credit default probabilities for some industries that banks should be adjusting their risk management procedures today. If they do so, the decreases in capital ratios identified in our study will be avoided. Therefore, we have proposed an instrument for calculating risks in order to take appropriate action at an early stage."

Risks to funds differ

In a second stress test, the team assessed the effects of companies' asset devaluations on two funds: an equity fund consisting mainly of EuroSTOXX 600 stocks and a mixed fund. Depending on the scenario, the equity fund would face a devaluation of 2.3–9.1 percent and the mixed fund in the 1.2–3.5 percent range.

"Although the effects on the funds vary considerably, especially with the equity fund the stress test shows that asset managers will have to manage the inherent climate risks in their portfolios very carefully" says co-author Sebastian Müller, professor of finance at TUM.

Integrating climate risk into established risk categories

"With this study we want to take the lead and provide a useful stimulus for practitioners and researchers alike as they develop approaches for the management of climate risks," says Gerold Grasshoff, the CEO of FIRM.

Taking the study as a starting point, financial practitioners of FIRM worked with the researchers to prepare recommendations for climate risk management. They advise financial institutions to implement intensive monitoring of climate risks and their economic interdependencies. To do this, the banks will need significantly more data on their debtors, for example with regard to their emission reduction targets. Because climate change will impact the entire economy, the task of making such data available should not be left to the banks alone. Instead, global standards should be established for uniform reporting on climate-related company data.

The group also advocates the inclusion of transitory climate risks in the existing risk categories for credit risk management. Due to possible overlapping, the researchers do not support the idea of a dedicated risk management concept for climate risks, as is currently under discussion.

European regulator urges banks to evaluate climate risks

More information: Gunther Friedl, Sebastian Müller, Alexander Schult, Approaches to climate risk methodology as an example of ESG risk management in finance (2021). go.tum.de/010988

Provided by Technical University Munich

Researchers caution global economic growth could slide into stagnation

by Sonia Fernandez, University of California - Santa Barbara

We've been living in a time of unprecedented global economic growth. Depressions, recessions and other dips in the economy notwithstanding, the last century has been unlike any other before in terms of overall Gross Domestic Product (GDP) per capita growth. It's the result of a potent combination of technology, via the Industrial Revolutions, and economic and political freedom and stability, thanks to the spread of democracy.

But the heady days of rapidly rising prosperity may be coming to an end, according to an interdisciplinary group of scientists at UC Santa Barbara and the University of Colorado Boulder. Developed democracies in particular look to be first in line for a long-run economic slowdown through the 21st century, and that, according to the researchers, should prompt some preparation for the additional fiscal and social stress that it will bring.

"Long-run slowdowns in growth in rich countries are inevitable for a bunch of reasons that we really don't have control over," said Matthew Burgess, the lead author of a paper that appears in the journal Nature Human Behaviour. "Nobody can say for sure exactly what's going to happen, but there's this long-term pattern of declining growth that has been visible since the middle of the last century."

Among the factors that may be implicated in this potential slowdown are aging populations, shifts from goods to services, slowing innovation, and debt. The extended effects of COVID-19 and climate change, the researchers say, could further slow growth.

"Given that future economic costs of human-driven environmental challenges like climate change can be enormous, aggressive action today on effective solutions is crucial to limiting future economic declines," said Steven Gaines, a co-author of the paper.

The news doesn't bode well for rich, democratic countries like the United States, which rely on long-term economic growth for many of their social safety net programs, job-creation investments, and to repay debt. The effects would ripple out to individuals as well, as slowing economic growth affects investments and savings that are crucial for education and retirement.

"I don't think there's quite enough of a deep appreciation of how much of our society we have built on growth," Burgess said, adding that the slowdown might persist for decades. While rapid growth has been implicated in many of our ecological woes, often leading to calls from the ecological community to slow down, thus far the position has been politically unrealistic, he said. Now, the question is: regardless of the politics, what if slow growth is inevitable?

A 'Guided Civic Revival'

"We need to start imagining a slow- to no-growth world," said Burgess, who is careful to point out that in the greater scheme of civilization, the last hundred years of economic growth have been the deviation, rather than the norm.

We take the kinds of growth we've seen in the last hundred years for granted, because so much of our memory and our ways of studying economics arose during this time when we were growing," he said.

The researchers propose a "guided civic revival," an approach that combines grass-roots, bottom-up civic forces with government participation to weather the potential long-term economic winter. Its goals would be to decouple social capital and individual well-being from economic growth; reduce inequality; improve opportunities for youth; increase the return on investment in government spending and taxation; and safeguard core institutional elements of democracy so they can withstand stress. The endgame? To promote unity in a storm of fiscal stresses that pose challenges to not just to our pocketbooks but also to society and democracy.

"I think the most important thing to ask ourselves is how do we build social solidarity in a context where things feel zero-sum," Burgess said. "Secondly, how do we adjust expectations?" For as long as most of us can remember, growth is assumed—it's part of the American Dream that over time, children will be better off economically than their parents. Recent statistics show that dream is fading, with at best 50% of people in their 30s today making more than their parents did, Burgess said. Yet many continue to assume that their ship will come in.

"There's lots of evidence that a gap between expectation and reality can be a catalyst for political unrest, especially among middle- and upper-class youth," he said.

Other solidarity-building exercises center around building a strong, shared identity while also making room for ethnocultural diversity, and lessening economic inequality by lowering the barriers to public education and providing job-relevant training.

Meanwhile, increasing the efficiency of public spending and reducing waste are fiscal strategies for the government to implement. The researchers suggest measures including spending on education, research and development, and infrastructure, while closing costly tax loopholes, reducing corruption and reforming the economically inefficient healthcare system. Savings and debt—our mechanisms for investing in the future as well as dealing with the present—may have to undergo a rethink in a stagnant economy, as exponential growth might no longer be relied on to reward us for buying a house, or contributing to education or retirement.

The measures the researchers propose are meant to be starting points from which to consider a slow-growth future, Burgess said. They could also be coupled with a shift in the assessment of well-being from the amount of income and affluence to the more subjective feelings of security, strong connections with family, personal freedoms, health, meaning, purpose and moral satisfaction.

"What does a successful, developed democracy look like amid long-run stagnation?" Burgess said. "In the modern United States, nobody really knows because it hasn't happened. The main goal of this paper is to start the conversation."Australia COVID measures to have 'profound' long-term impact

More information: Matthew Burgess, Prepare developed democracies for long-run economic slowdowns, Nature Human Behaviour (2021). DOI: 10.1038/s41562-021-01229-y. www.nature.com/articles/s41562-021-01229-y

Journal information: Nature Human Behaviour

Provided by University of California - Santa Barbara