Environmental choices the Romans made

The Roman Empire was the world's first superpower and controlled millions of square miles at its height — everything between modern-day Spain up to England and across to Armenia, down through Egypt and over to Morocco. Millions of people from different tribes and cultures were governed by Roman law, mixing and mingling their respective religions, technology, customs and knowledge. Roman thinkers, artists, writers and philosophers helped expand our understanding of engineering, agriculture, architecture, law and the arts.

 At its most populated, the city of Rome had more than 1 million citizens living within its borders. Most people lived in apartment buildings, and the city held a number of industrial businesses like blacksmiths, tanneries, slaughterhouses and concrete manufacturers. The dense concentration of people and industry created a lot of pollution — especially with thousands of smoky fires for cooking and heating burning daily.

Click here to read this article from the Mother Nature Network

From Ancient Deforestation, a Delta Is Born

Humans were tampering with nature long before the Industrial Revolution’s steam and internal combustion engines arrived on the scene. The invention of agriculture around 8,000 years ago, some argue, significantly changed ecosystems as it spread around the globe.

 Although scientists are only just beginning to understand how these ancient alterations shaped our world today, a new study in Scientific Reports suggests that millennium-old development along the Danube River in Eastern Europe significantly changed the Black Sea ecosystem and helped create the lush Danube Delta in Romania and Ukraine.

 “My team had a big surprise,” said Liviu Giosan, a geologist at the Woods Hole Oceanographic Institution in Massachusetts and the lead author of the study. “We found that around a thousand years ago, the entire basin changed dramatically, though that later made sense when we put it into context.”

Click here to read this article from the New York Times

See also: Early Anthropogenic Transformation of the Danube-Black Sea System

An Ancient Civilization, Upended by Climate Change

The Vedas, a collection of texts composed over 3,000 years ago in India, speak of a mythical sacred river called the Sarasvati from which the Hindu goddess of science and learning emerged. Hers was a river “surpassing in majesty and might all other waters.” But around 4,000 years ago, all was lost when climate change kicked in.

 That is the conclusion of a group of geologists, geomorphologists, archaeologists and mathematicians who joined forces to answer a question that has dogged scholars for centuries: what became of the Indus civilization?

 This colossal civilization rose about 4,500 years ago, flourished for 600 years and then began a steady and relentless decline. Previous scholars hypothesized that regional strife or a foreign invasion led to its unraveling, while others suggested that environmental factors may have been to blame. The researchers who took part in the new study, published in the Proceedings of the National Academy of Sciences, had a hunch that the latter theory was correct.

 “What we thought was missing was how to link climate to people,” said Liviu Giosan, a geologist at the Woods Hole Oceanographic Institution in Massachusetts and the lead author of the study. “The answer came when we looked at the wide-scale morphology.”

Click here to read this article from the New York Times

See also Migration of monsoons created, then killed Harappan civilization

Warning signs from ancient Greek tsunami

In the winter of 479 B.C., a tsunami was the savior of Potidaea, drowning hundreds of Persian invaders as they lay siege to the ancient Greek village. New geological evidence suggests that the region may still be vulnerable to tsunami events, according to Klaus Reicherter of Aachen University in Germany and his colleagues.

The Greek historian Herodotus described the strange retreat of the tide and massive waves at Potidaea, making his account the first description of a historical tsunami. Reicherter and colleagues have added to the story by sampling sediments on the Possidi peninsula in northern Greece where Potidaea (and its modern counterpart, Nea Potidea) is located. The sediment cores show signs of “high-energy” marine events like significant waves, and excavations in the suburbs of the nearby ancient city of Mende have uncovered a high-energy level dated to the 5th century B.C. The Mende layer contains much older marine seashells that were probably scoured from the ocean bed and deposited during a tsunami.

Click here to read this article from History of the Ancient World

Vikings not alone when they crossed the North Atlantic – mice hitched a ride too

New research has revealed that when the Vikings sailed across the North Atlantic to places like Iceland, Greenland and Newfoundland, they brought with them the common house mouse. An international team of researchers from the UK, USA, Iceland, Denmark and Sweden examined the mitochondrial DNA of these mice to see where their origins were from. Their article, “Fellow travellers: a concordance of colonization patterns between mice and men in the North Atlantic region” was published in BMC Evolutionary Biology.

During the Viking age (late 8th to mid 10th century) Vikings from Norway established colonies across Scotland, the Scottish islands, Ireland, and Isle of Man. They also explored the north Atlantic, settling in the Faroe Islands, Iceland, Newfoundland and Greenland. While the Norse settlers took with them domestic animals such as horses, sheep, goats and chickens they also inadvertently carried pests like mice.

The researchers used techniques designed to characterize genetic similarity, and hence the relatedness of one population, or one individual, with another, to determine a mouse colonisation timeline.

Click here to read this article from Medievalists.net

The Vikings: Victims and victors

It's ironic that we remember the Vikings best for one small failure -- their frozen far-north Greenland colony. We should instead be praising the Vikings for struggling through the cold and stormy Dark Ages, for designing those fabulous dragon ships, for swaggering their way through the abundance of the Medieval Warming -- and ultimately for leaving many of their descendents in warmer locations to survive the Little Age..

Overall, the Norse were big winners in their struggles with the earth's abrupt climate change cycles. When the cold, stormy Dark Ages set in about AD 600, the Norse had just succeeded in clearing enough Scandinavian land to support their dairy cattle and a few hardy crops. They had also developed their famous long-ships, for catching codfish on the Dogger Banks offshore.

Then, suddenly, the Dark Ages shortened the northern farmers' already-short cropping season by weeks. The colder and stormier seas drove the codfish and herring further south, away from their nets and hand-lines. Even their trading voyages became far more dangerous.

Click here to read this article from Enter Stage Right

Mayan civilization collapsed because of modest rainfall reduction, study says

A new study reports that the disintegration of the Maya civilization may have been related to relatively modest reductions in rainfall.

The study was led by Professors Martín Medina-Elizalde of the Yucatan Center for Scientific Research in Mexico and Eelco Rohling of the University of Southampton in the UK.

Professor Rohling explains, “Our results show rather modest rainfall reductions between times when the Classic Maya civilization flourished and its collapse – between AD 800-950. These reductions amount to only 25 to 40 per cent in annual rainfall. But they were large enough for evaporation to become dominant over rainfall, and open water availability was rapidly reduced. The data suggest that the main cause was a decrease in summer storm activity.”

Click here to read this article from History of the Ancient World

Arabic sources show extreme weather hit medieval Baghdad

Medieval manuscripts written by Arabic scholars can provide valuable meteorological information to help modern scientists reconstruct the climate of the past, a new study has revealed. The research, published in Weather, analyses the writings of scholars, historians and diarists in Iraq during the Islamic Golden Age between 816-1009 AD for evidence of extreme weather in Iraq, including snowfalls and hailstorms in Baghdad.

Reconstructing climates from the past provides historical comparison to modern weather events and valuable context for climate change. In the natural world trees, ice cores and coral provide evidence of past weather, but from human sources scientists are limited by the historical information available.

Click here to read this article from Medievalists.net

We can learn lessons from Vikings to adapt to global change

History can teach us how best to respond to climate change, economic turmoil and cultural upheaval, which seems to be pressing concerns of today, scientists have suggested.

Scientists studying the past environments and archaeological remains of Greenland and Iceland ave been able to analyse how well the Norse responded to changes in the economy, trade, politics and technology, against a backdrop of changing climate.

They found that Norse societies fared best by keeping their options open when managing their long-term sustainability, adapting their trade links, turning their backs on some economic options and acquiring food from a variety of wild and farmed sources. The researchers say their findings could help inform decisions on how modern society responds to global challenges.

In the middle ages, people in Iceland embraced economic changes sweeping Europe, eveloped trading in fish and wool and endured very hard times to build a flourishing modern society.

Click here to read this article from Yahoo News


Click here to read 'Scientists suggest looking into history to learn climate change lessons'

Volcanic activity behind Little Ice Age

Melting icefields on Baffin Island, one of the clearest signs of climate change on Earth, have yielded the strongest evidence yet for the timing and cause of another major climate event from the planet's past: the so-called Little Ice Age, a sudden and mysterious cooling of the globe that began about 700 years ago.

Recently exposed remains of plants that had been buried under Baffin Island ice for centuries provided the crucial clue that has led an international team of researchers to conclude the Little Ice Age was triggered by volcanic eruptions between 1275 and 1300 and was sustained by changes in Arctic sea-ice cover that lasted several centuries.

Writing in the latest issue of the journal Geophysical Research Letters, the team of 13 scientists from the U.S., Iceland and Britain notes that, "there is no clear consensus on the timing, duration, or controlling mechanisms" of the Little Ice Age, which has been attributed by some experts to the onset of a period of reduced heat from the sun.

Click here to read this article from the Vancouver Sun

See also Volcanoes and the Little Ice Age: Not the Smoking Gun? - from Wired.com

Researchers look to ancient art to study Mediterranean Fish

The dusky grouper has been a popular target for Mediterranean fishermen since prehistoric times – their bones have been found in human settlements dating back more than 100,000 years. It’s a slow growing, flavourful and, with the advent of modern sport fishing, endangered species.

In an effort to reverse the decline of multiple species, including groupers, a number of no-take marine reserves have been established across the Mediterranean. But it’s proven difficult to evaluate the success of these protected areas precisely because humans have had an impact on the species for so long. Ideally, reserve biologists would compare modern fish to groupers hundreds or thousands of years ago, before the advent of large-scale commercial fishing.

Click here to read this article from History of the Ancient World

500 years ago, yeast’s epic journey gave rise to lager beer

In the 15th century, when Europeans first began moving people and goods across the Atlantic, a microscopic stowaway somehow made its way to the caves and monasteries of Bavaria.

The stowaway, a yeast that may have been transported from a distant shore on a piece of wood or in the stomach of a fruit fly, was destined for great things. In the dank caves and monastery cellars where 15th century brewmeisters stored their product, the newly arrived yeast fused with a distant relative, the domesticated yeast used for millennia to make leavened bread and ferment wine and ale. The resulting hybrid – representing a marriage of species as evolutionarily separated as humans and chickens – would give us lager, the clear, cold-fermented beer first brewed by 15th century Bavarians and that today is among the most popular – if not the most popular – alcoholic beverage in the world.

Click here to read this article from Medievalists.net

Climate helped drive Vikings from Greenland

The end of the Norse settlements on Greenland likely will remain shrouded in mystery. While there is scant written evidence of the colony’s demise in the 14th and early 15th centuries, archaeological remains can fill some of the blanks, but not all.

What climate scientists have been able to ascertain is that an extended cold snap, called the Little Ice Age, gripped Greenland beginning in the 1400s. This has been cited as a major cause of the Norse’s disappearance. Now researchers led by Brown University show the climate turned colder in an earlier span of several decades, setting in motion the end of the Greenland Norse. Their findings appear in Proceedings of the National Academy of Sciences.

Click here to read this article from Medievalists.net

Medieval recycling: A historian looks at fifth century Britain to shed fresh light on ‘reduce, reuse, recycle’

Historian Robin Fleming’s recent lecture at Harvard was on economic calamity in early medieval Britain, and how people in desperate straits turned to “recycling” Roman ruins for what they needed.

The Radcliffe Fellow, on leave from Boston College, used dozens of slides — of knights in helmets, stone churches, iron fixtures, and more. But one picture was contemporary: a Haitian man, hammer poised in midair, scavenging rebar from post-earthquake rubble.

Perhaps fifth century Britain, thrown into abject poverty by the withdrawal of Roman power, offers a lesson to the modern world. In some countries, after all, culture, industry, and governance are fragile too, and await the fall of some modern Rome.

Click here to read this article from the Harvard Gazette

See also the interview we did with Robin Fleming in November 2010:

Environmental Crusaders: How Medieval Knights remade Poland’s ecosystems

In 1280, victorious Teutonic Crusaders began building the world’s largest castle on a hill overlooking the River Nogat in what is now northern Poland. Malbork Castle became the hub of a powerful Teutonic state that crushed its pagan enemies and helped remake Medieval Europe. Now, ancient pollen samples show that in addition to converting heathens to Christians, the Crusaders also converted vast swathes of Medieval forests to farmlands.

Click here to read this article from Conservation Magazine

Climate Change and the Fall of the Roman Empire - lecture at the University of Maine

On Tuesday, April 26, Hudson Museum at the University of Maine will present a lecture by Michael McCormick, the Francis Goelet Professor of Medieval History at Harvard University, whose research and teaching focuses on the archaeology and history of the fall of the Roman Empire and the origins of medieval civilization.

In “Climate Change and the Fall of the Roman Empire,” McCormick will explore what bio-molecular evidence and climate change data suggest about the impact of volcanic events on the collapse of the Roman Empire and the rise of Carolingian Europe. Drawing on ice core evidence and primary documentary research for the period 750 to 950 AD, McCormick will explore the impact of volcanic events on the collapse of the Roman Empire and the rise of Carolingian Europe. Climate cooling caused by eight volcanic events, resulted in nine major winter anomalies that affected food production and human survival.

The lecture will be given at 7 p.m. in Hutchins Hall, Collins Center for the Arts, is free and open to the public.


Source: University of Maine

Monks' diaries to help weather forecast

Medieval weather records, including details from monks' diaries are helping experts work out how and why climates have changed over the past 500 years.

Edinburgh University scientists found the historic data, such as harvest records, matched modern computer simulations of climate patterns.

Researchers have assembled climate models to account for past events. They expect the models to work well for forecasting future climate conditions, especially predicting temperatures.

Click here to read this article from the BBC

Click here to see the press release from the University of Edinburgh

Coolness in the Pacific changed medieval Europe's climate, study says

A cooler central Pacific Ocean has been connected with drought conditions in medieval Europe and North America, and may also have been responsible for famines and the disappearance of cliff dwelling people in the American West.

A new study from the University of Miami (UM) has found a connection between La Niña-like sea surface temperatures in the central Pacific and droughts in western Europe and in what later became the southwestern United States and Mexico, as published in a recent issue of Geophysical Research Letters.

"We've known for some time the connection between El Niño and La Niña and the weather conditions in North America and Europe," said Robert Burgman, a climate scientist at UM's Rosenstiel School of Marine and Atmospheric Science. "La Niña-like conditions, such as those we found, can cause persistent drought, and as we know warm conditions cause increased precipitation."

Using cores of fossil coral from the Palmyra Atoll in the central Pacific Ocean, Burgman and a team used reconstructed sea surface temperatures from the period 1320 to 1462 to simulate medieval climate conditions with a state-of-the-art climate model. When the differences between medieval and modern climate simulations were compared with paleo-records like tree-rings and sediment cores from around the globe, the authors found remarkable agreement.

During the 142-year study period, the sea surface temperature dropped only one-tenth of one degree, but it was enough to cause arid conditions in North America and Europe.

In Europe, the study period was preceded by three years of torrential rains, which led to the Great Famine from 1315 to 1320, and marked the transition from the Medieval Warm Period to the Little Ice Age, which began in the mid 1500s. During that time, extreme weather conditions were thought to be responsible for continued localized crop failures and famines throughout Europe during the remainder of the 14th Century.

In North America, the Anastazi people—who lived in dramatic cliff dwellings near what later became known as the "Four Corners" area at the intersection of the state of Utah, Colorado, New Mexico, and Arizona—left their settlements at Mesa Verde and other locations some 600 years ago without explanation. A prolonged drought is thought to be one of the contributing factors to their departure.

"The marriage of complex climate models with paleo-records of sea surface temperature and other climate variables provide valuable insight to climate scientists who wish to understand climate variability and change before the instrumental record," said Burgman.

Warning that the Palmyra Atoll data only represents one data point, Burgman emphasized that he would like to test his thesis with data from other oceans. "If we can fill in the gaps with data from corals and other records from the Atlantic, Pacific, and Indian oceans, we'll have a better idea of what has happened to the global climate over time," he added.

In the study, Burgman and his colleagues used the reconstructed tropical Pacific sea surface temperatures to create a 16-member ensemble of atmospheric general circulation model (ACGM) simulations, coupled with a one-layer ocean model outside of the tropical Pacific. When the ACGM simulations were compared with the modern climate simulations, they were able to reproduce many aspects of the medieval climate found in observational records for much of the Western Hemisphere, northern Eurasia, and the northern tropics. These results suggest that many features of global medieval hydroclimate changes can be explained by tropical Pacific sea surface temperatures.

Source: EurekAlert

Researchers track climate change in northwest Africa back to the Middle Ages

An international research team has figured out northwest Africa's climate history by using the information recorded in tree rings. The trees sampled contain climate data from the medieval period, including one from Morocco that dates back to the year 883.

The climate of a region that includes Morocco, Algeria and Tunisia has now been analyzed back to the year 1179 and shows that frequent and severe droughts occurred during the 13th and 16th centuries.

"Water issues in this part of the world are vital," said lead researcher Ramzi Touchan of the University of Arizona. "This is the first regional climate reconstruction that can be used by water resource managers."

In most of North Africa, instruments have been recording weather information for 50 years or less, too short a time to provide the long-term understanding of regional climate needed for resource planning, he said.

"One of the most important ways to understand the climate variability is to use the proxy record, and one of the most reliable proxy records is tree rings," said Touchan, an associate research professor at UA's Laboratory of Tree-Ring Research.

The team has developed the first systematically sampled network of tree-ring chronologies across Northwest Africa, said co-author David Meko, also of UA's Laboratory of Tree-Ring Research.

The network allowed the researchers to analyze the patterns of past droughts over the whole region, said Meko, a UA associate research professor. The width of the annual growth rings on trees in semi-arid environments is highly correlated with the amount of precipitation.

The team found the region's 20th-century drying trend matches what climate models predict will occur as the climate warms. The research is the first to compare projections from climate models with tree-ring-based reconstructions of the region's past climate.

The region's trees and dead wood needed to do such research are disappearing rapidly from a combination of a massive die-off of trees, logging and population pressures, Touchan said.

"We have a chance to do what we call salvage dendrochronology," Touchan said. These are areas where we need to get this information now or it's going to disappear."

Pointing to a cross-section of an old tree from Morocco, he said, "This is from 883–and this is from a stump. If we don't take them, they're gone. So this is a real treasure."

The team's paper, "Spatiotemporal drought variability in northwestern Africa over the last nine centuries," is now available online and will be published in a future issue of the journal Climate Dynamics. The National Science Foundation funded the research.

The team sampled several different species of conifer and oak trees, because research indicates that testing several different species from the same region provides a better indicator of regional climate.

The current tree-ring chronology builds on previous work in Northwest Africa by this team and by other researchers. The chronology incorporates samples from at least 20 trees from each of 39 different sites.

Persistent drought was more widespread across Northwest Africa before the year 1500 than for the four centuries following, the researchers found. However, the pattern of widespread regional drought then seems to re-emerge in the late 20th century.

The spatial extent of the new regional tree-ring chronology revealed that drought in Morocco is not driven by the same kinds of oceanic and atmospheric conditions as drought in Algeria and Tunisia.

Drought in Morocco is strongly related to the north/south seesaw of air-pressure anomalies in the North Atlantic Ocean called the North Atlantic Oscillation. However, drought in Morocco is only weakly related to El Nino. By contrast, drought in Algeria and Tunisia appears more linked to a warm tropical Atlantic Ocean.

Touchan hopes to expand the new network's geographic reach to across North Africa, including Libya and additional parts of Algeria. In addition, he wants to extend the chronology back in time to bridge the gap to archaeological material.

Tree-ring chronologies exist for centuries deep in the past, but they are "floating," meaning that there is no continuous record linking those chronologies to ones that reach back from the present, he said. "If we can bridge this gap, it will be a discovery for the world," Touchan added.

Touchan and Meko's co-authors are Kevin J. Anchukaitis of Columbia University's Lamont Doherty Earth Observatory in Palisades, N.Y.; Mohamed Sabir of the National School of Forest Engineering in Sale, Morocco; Said Attalah of the University of Ourgla in Algeria; and Ali Aloui of the Institute of Sylvo-Pastoral of Tabarka in Tunisia.

Click here to access the article from SpringerLink

See also The development of an Early Historic tree-ring chronology for Scotland

Source: University of Arizona

Lecture looks at environmental changes in medieval Scotland

Professor Richard Oram of the University of Stirling will be delivering a lecture next week where he examines environmental changes in northern Scotland during the Middle Ages and how medieval people had to cope with climate shifts. His talk, ‘Environmental Heritage in the Highlands and Islands’, will take place in Inverness on Thursday 29 April. The event is free and open to all, and takes place at the Centre for Health Science, Raigmore Hospital, at 5.30pm.

According to Professor Oram, there is a remarkable concurrence between some of most dire events in human history and the depths of the episodes of climate change taking place at those times. “Climate change occurs when global warming increases weather instability and variability,” he explains. “While these weather changes may be subtle year on year, they can be profound over just a few decades. This can affect every aspect of people’s livelihoods – whether that’s fishing, working the land or rearing livestock – so inevitably, it affects their lives.

“Archaological evidence shows that, throughout history, major environmental events have occurred which have dramatically impacted human culture and society. In almost every case, society has demonstrated resilience and the ability to adapt to its changing circumstances in sustainable ways.

“We have enjoyed a long period of relative environmental stability. But nothing stands still – especially not Nature,” says Professor Oram. “Things definitely began to change in the 20th century: before this there had been a measure of predictibility about the pace and scale of environmental change but our current situation is unprecedented because everything is changing at a much faster speed.

“The good news is that this time around, the Highlands and Western Isles are well placed to develop what is potentially a positive side to the hand we’re now being dealt by Nature. Wind and water are elements which, together with our technological edge, can be turned to communities’ advantage.”

In 900 AD the Medieval warm era had just begun, bringing to the Scottish Highlands a climactic pattern of relative stability, with average temperatures around 1.5% higher than they are today. For almost 300 years, this encouraged a Highland pastoral society in which livestock numbers greatly increased, cereals such as wheat could be grown and crops generally were more abundant, owing to the dryer, warmer climate conditions. The result was higher populations, a buoyant economy and more tax revenues.

According to Professor Oram, the European population reached a peak in 1300 AD. But conditions were changing and the period now known as the Little Ice Age had begun. The spread of sea ice caused a change in north Atlantic surface temperatures, which in turn altered the high pressure systems throughout the year. This created a ‘refrigerator’ effect and caused temperatures to drop dramatically. By the middle of the 14thcentury, the growth period for crops had started two weeks later and stopped two weeks earlier. With animal grazing now restricted to lower altitudes, feed became scarcer. Crops began to fail and there were outbreaks of livestock disease, famine, and human epidemics.

Meanwhile storms and winds eroded the machair and the cultivated land beyond, so that whole areas became overwhelmed by sand. Economically, this was the final catastrophe for many on Scotland’s west coast and evidence from archaological sights of that period point to the sudden abandonment of villages – such as the herring fishing communities of Bornish.

Subsequent centuries were marked by environmental extremes, accompanied by widespread famines, and epidemics of influenza, cholera and malaria. Social unrest led to revolution and wars and it wasn’t until the 18th century that population numbers began to recover.

Professor Oram has published widely on aspects of Scottish medieval history and archaeology, including books on The Lordship of Galloway c.900 to c.1300, Domination and Lordship: Scotland c.1070-c.1230, Viking Empires, David I and an edited volume on Alexander II. He is currently working on Holy Frontiersmen? The Monastic Impact on the Northern European Environment c.1100-c.1350.

Professor Grant Jarvie, Deputy Principal of the University of Stirling, said: “We have a long-standing commitment to the Highlands and Islands, and our world-class scholars and researchers are focused upon key areas of life in the area. The Stirling Lectures this year focus on the environment, bringing this research to a wider audience.”

The lecture was orginally scheduled to took place on February 25, but was postponed due to adverse weather conditions. To reserve a place or for further information, telephone 01463 255649 or email hct1@stir.ac.uk

Source: University of Stirling