AIR POLLUTION

Human impact on solar radiation levels for decades

ETH ZURICH

Research News

 

In the late 1980s and 1990s, researchers at ETH Zurich discovered the first indications that the amount of sunlight reaching the Earth's surface had been steadily declining since the 1950s. The phenomenon was known as "global dimming". However, a reversal in this trend became discernible in the late 1980s. The atmosphere brightened again at many locations and surface solar radiation increased.

"In previous studies, we showed that the amount of sunlight that reaches the Earth's surface is not constant over many decades but instead varies substantially - a phenomenon known as global dimming and brightening," says ETH Professor Martin Wild of the Institute for Atmospheric and Climate Science.

Natural variations or air pollution?

Yet little is known about the reasons for these fluctuations, which have been observed for decades. One particularly controversial point is whether the fluctuations are caused by air pollution, with aerosols blocking the sunlight, or whether they are a result of natural variations in the climate system.

A number of scientists suspected that cloud cover may have changed over the years, absorbing the sun's rays more effectively during the dimming phase than during the brightening phase.

This is why Wild and colleagues from other research institutes analysed measurements collected between 1947 and 2017 in the Potsdam radiation time series, which is renowned among climate researchers. The series offers one of the longest, most homogeneous, continuous measurements of solar radiation on the Earth's surface.

Dimming also occurred in cloud-free conditions

In this new study, they were able to show that rather than these fluctuations being due to natural changes in the cloud cover, they are instead generated by varying aerosols from human activity. The paper was published in the journal Geophysical Research Letters.

"In our analysis, we filtered out the effects of cloud cover to see whether these long-term fluctuations in solar radiation also occurred in cloud-free conditions," Wild explains. As it turned out, the decadal fluctuations in the sunlight received at the Earth's surface were apparent even when skies were clear.

The researchers identified aerosols entering the atmosphere due to air pollution as the major contributor to global dimming and brightening. "Although we'd already assumed as much, we'd been unable to prove it directly until now," he says.

Brightening after economic collapse

The fact that the transition from dimming to brightening coincided with the economic collapse of the former communist countries in the late 1980s supports the argument that these variations have a human cause. Moreover, around this time, many western industrialised nations introduced strict air pollution regulations, which improved air quality significantly and facilitated the transfer of the sunbeams through the atmosphere. Lastly, the atmosphere was recovering from the volcanic eruption of Mount Pinatubo, which had ejected vast amounts of aerosols into the air in 1991.

Wild and his colleagues had already ruled out fluctuations in solar activity in an earlier study. "The sun itself had only an infinitesimal, negligible effect, which in no way accounts for the magnitude of the intensity changes that had been observed over the years at the surface," Wild says.

Dimming reduced evaporation and precipitation

Surface solar radiation is a key parameter for climate issues. Not only does it govern the temperature, it also has a fundamental impact on the water cycle by regulating evaporation, which, in turn, governs cloud formation and affects precipitation. During the global dimming, less water evaporated from the Earth's surface, causing precipitation to decline worldwide.

Solar radiation also affects the cryosphere, i.e. glaciers, snow and ice. "Glacial retreat accelerated when the atmosphere began brightening again," Wild says, adding: "It's also becoming increasingly important for the solar industry to gain a better understanding of these fluctuations when it comes to planning new facilities."

Germany's National Meteorological Service, the Deutscher Wetterdienst, operates an observatory in Potsdam that has been measuring solar radiation since 1937. This means the station boasts one of the world's longest radiation time series. "I'm extremely grateful to have access to decades' worth of data; after all, it is only thanks to measurement series such as this that we're able to record and show changes in our environment and climate," Wild says, adding that this makes it imperative to support monitoring networks around the world for prolonged periods of time. Admittedly, this task isn't particularly spectacular, making it difficult to secure funding. "But if we want to understand climate change and clarify the impact of human activities, we need time series that go back far enough," he says. To this end, ETH maintains the Global Energy Balance Archive (GEBA), an unparalleled database of surface energy fluxes worldwide.

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The Nazis looted Europe's treasures. A U.S. Supreme Court ruling casts doubt on their return.

Yasmine Salam, Carlo Angerer and The Associated Press 1 day ago

It was no ordinary art deal.

The sale of a precious medieval collection by a group of tradesmen to the Prussian government in 1935 was notable not only for its treasured contents, but also for its participants.

The sellers were Jewish, a fact that defined their fate in Nazi Germany and hangs over the transaction to this day.

“They know they're under the gun,” Marc Masurovsky, a historian who specializes in plundered art during the Holocaust, said from his home in Washington. “The average position of Jews in Germany as of 1933 is nothing short of dangerous, perilous, fragile and precarious.”

Though historical consensus is clear that state-sponsored Jewish persecution took place from the start of Adolf Hitler’s rule, today three heirs of those very art dealers are struggling to prove just that.

And experts fear a recent U.S. Supreme Court ruling could prove a bitter blow not only to those heirs, but also to hundreds of Jewish families seeking restitution from Germany as it struggles to atone for its past.© Tobias Schwarz Image: Detail of a reliquary crucifix of the so-called 'Welfenschatz' (Guelph Treasure) is pictured at the Kunstgewerbemuseum (Museum of Decorative Arts) in Berlin on Feb. 24, 2015. (Tobias Schwarz / AFP - Getty Images file)

Pressured by agents sent by Hermann Goering, the second-most-powerful man in the Third Reich, the dealers sold half of the golden Guelph Treasure to the state for what the heirs say was a third of its value.

After a decadelong fight that saw a German commission on Nazi-looted art reject their claims that the treasures were forcibly sold, the heirs took their case across the pond.

But earlier this month America’s highest court unanimously ruled it had no jurisdiction in the case, as the Germans had argued.

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The Prussian Cultural Heritage Foundation, which runs Berlin’s state museums, has fought to keep the collection in the city’s Museum of Decorative Arts. It attributed the low sale price to tough negotiations in a damaged art market reeling from Europe’s financial crash, rather than Nazi persecution.

A bipartisan group of U.S. lawmakers called the claim that pre-1939 conditions for Jews in Germany were not persecutory “deeply concerning” in a letter to the country’s ambassador in Washington in October.

“Hearing your grandparents being accused of simply being dissatisfied with whether they made enough profit in 1935 in Nazi Germany is pretty brutal,” said Nicholas O’Donnell, the heirs’ lawyer.

“By the time my clients came to me they felt very ill-treated by the German government.”© ullstein bild via Getty Images file Exhibition visitors in front of the Reliquary dome (Cologne, 1175), main piece of the Welfenschatz, in 1930. (ullstein bild via Getty Images file)

The treasures are now worth an estimated $250 million, but the cost of the case and others like it runs much deeper.

Germany has garnered praise for addressing its dark history, with concerted efforts in education and cultural spaces, but recent years have seen a resurgence in far-right support and anti-Semitism.

And while it also established the expert commission specifically to handle such cases, Jewish families and experts alike have cast doubt on the country’s appetite to help heirs retrieve their stolen property.

The Nazis seized an estimated 20 percent of art in Europe, with scores of items still not returned to the families that owned them.

Faced with the hefty task, dozens of countries signed up to the Washington Principles on Nazi-confiscated art in 1998 in an effort to boost the process.

The German federal government has appealed to private owners, collectors and institutions to follow the nonbinding agreement — under which thousands of objects have been returned to their rightful owners — a spokesman for the commissioner for culture and media said.

But Germany's restitution system fares poorly compared to neighboring countries, experts said, particularly in its speed.

The commission has dealt with a mere 18 cases since its creation in 2003. Compared to Austria, the light caseload reflects Germany’s “ad-hoc” approach, O’Donnell said.

“Germany doesn't deserve a win in Nazi restitution cases and I fear that this procedural victory will prejudice other claimants going forward,” said Christopher Marinello, a lawyer and the CEO of Art Recovery International, a firm that specializes in returning looted art. “Seventy-six years after the war, German laws remain wholly inadequate to deal with Nazi-restitution claims,” he added.

Enforcement is also an issue, with the commission struggling to implement its decision over a Jewish family’s rare 300-year-old Guarneri violin in a case that has drawn recent media attention.

It determined in 2016 that the instrument, currently owned by a private music foundation in Nuremberg, was either forcibly sold or seized by the Gestapo after Felix Hildesheimer's family fled persecution.

© Courtesy of Sidney Strauss Felix Hildesheimer plays piano accompaniment as his youngest daughter plays the violin in 1930s Speyer, Germany (Courtesy of Sidney Strauss)

Because of scant surviving sales records, the commission urged the music foundation to pay the equivalent of $120,000 to the family's surviving grandchildren and keep the violin as a compromise.

But four years later, the heirs have still not received the funds. Last month, the commission issued a stern censure to no avail.

A spokesman said the commission's proposals are not legally binding for citizens and private foundations due to legal fears over infringements on property rights.

Marinello, who is in a separate bitter tussle with Germany on behalf of a Jewish family hoping to retrieve their stolen Degas painting, described stalemates in such cases as “typical.”

“There has been an ever-increasing level of frustration on the part of everyone,” said Sidney Strauss, Hildesheimer’s grandson.

“It is also very important to remember that behind every item reviewed by the commission is a unique, personal family story,” he added. "That may include the loss of a business or a life."

For families like his, the fight to reclaim what they still can goes on.

Poor swelter as urban areas of US Southwest get hotter

Unequal burden also for Latino communities

UNIVERSITY OF CALIFORNIA - DAVIS

Research News

 

IMAGE: THIS STUDY PROVIDES THE MOST DETAILED MAPPING YET OF HOW SUMMER TEMPERATURES IN 20 URBAN CENTERS IN CALIFORNIA, NEVADA, UTAH, ARIZONA, COLORADO, NEW MEXICO AND TEXAS AFFECTED DIFFERENT NEIGHBORHOODS BETWEEN... view more 

CREDIT: STUDY AUTHORS.

Acres of asphalt parking lots, unshaded roads, dense apartment complexes and neighborhoods with few parks have taken their toll on the poor. As climate change accelerates, low-income districts in the Southwestern United States are 4 to 7 degrees hotter in Fahrenheit -- on average -- than wealthy neighborhoods in the same metro regions, University of California, Davis, researchers have found in a new analysis.

This study provides the most detailed mapping yet of how summer temperatures in 20 urban centers in California, Nevada, Utah, Arizona, Colorado, New Mexico and Texas affected different neighborhoods between 2018 and 2020. The researchers found even greater heat disparities in California than in other states. The largest disparities showed up in the Riverside and San Bernardino County urban areas.

The unequal impact on Latino communities was especially apparent, the authors said. In Los Angeles on a hot summer day, for example, the most heavily Latino neighborhoods were 6.7 degrees hotter than the least Latino neighborhoods.

"This study provides strong new evidence of climate impact disparities affecting disadvantaged communities, and of the need for proactive steps to reduce those risks," said the study's lead author, John Dialesandro, a doctoral student in geography in the Department of Human Ecology.

The authors said that lower socio-economic groups often have less access to cooled housing, transportation, workplaces and schools. Excess heat can cause heat stroke, exhaustion, and ampli?ed respiratory and cardiovascular issues.

It has long been known that paved surfaces of urban areas absorb and retain solar radiation, increasing urban temperatures. The surrounding suburbs -- with more plant life, parks or proximity to bodies of water -- will be cooler, creating heat islands in the denser areas.

"There is a strong need for state and local governments to take action to mitigate heat disparities by reducing paved surfaces, adding drought-tolerant vegetation, and encouraging building forms that increase shade and reduce temperatures," Dialesandro said.

The study was published in the International Journal of Environmental Research and Public Health. Co-authors include Noli Brazi, assistant professor, and Stephen Wheeler, professor, each in the Department of Human Ecology, and Yaser Abunnasr, Department of Landscape Design and Ecosystem Management, American University of Beirut.

Researchers looked at U.S. Census data for each area studied, focusing on median household income and percentage of Latinx, Black and Asian populations in each. They also looked at education levels attained. They then assessed radiant and atmospheric temperatures recorded by satellite on the warmest summer days and nights in those cities over a two-year period.

On average, the poorest 10 percent of neighborhoods in an urban region were 4 degrees hotter than the wealthiest 10 percent on both extreme heat days and average summer days, the study said.

California's urban regions had much larger temperature differences between the wealthiest and poorest neighborhoods compared with regions in the rest of the Southwest. The greatest differences were seen in Palm Springs, Bakersfield and Fresno. The smallest differences were seen in Sacramento.

On extreme heat days, the poorest California neighborhoods in each region were nearly 5 degrees hotter, on average, than the wealthiest neighborhoods. This compares to about 3 degrees difference in average temperatures for other Southwestern cities when comparing wealthier and poorer neighborhoods.

The largest differences occurred in the Inland Empire and Palm Springs areas in Riverside and San Bernardino County, where disparities in average temperatures between wealthier and poorer differed by more than 6 degrees.

"Programs to increase vegetation within disadvantaged neighborhoods and reduce or lighten pavements and rooftops could help reduce thermal disparities between neighborhoods of different socioeconomic characteristics," the authors said.

While neighborhoods populated by Blacks in Southern California showed some disparities in temperature -- about 1 to 2 degrees, when compared with white neighborhoods -- this difference was not statistically significant. Black populations throughout Southwestern metropolitan areas are relatively small, authors said, meaning that findings on this demographic dimension were less pronounced.

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Songbirds' reproductive success reduced by natural gas compressor noise

Novel research reveals bluebirds, tree swallows seemingly ignore noise at first; pay later

PENN STATE

Research News

 

IMAGE: BOTH BLUEBIRDS AND TREE SWALLOWS, LIKE THIS ONE, NESTING IN NOISY BOXES SPENT LESS TIME INCUBATING THEIR EGGS, HAD FEWER EGGS HATCH AND PRODUCED FEWER YOUNG THAN THEIR NEIGHBORS NESTING... view more 

CREDIT: JULIAN AVERY, PENN STATE

Some songbirds are not dissuaded by constant, loud noise emitted by natural gas pipeline compressors and will establish nests nearby. The number of eggs they lay is unaffected by the din, but their reproductive success ultimately is diminished.

That's the conclusion of a team of Penn State researchers who conducted an innovative, elaborate study that included unceasing playback of recorded compressor noise, 80 new, never-before-used nest boxes occupied by Eastern bluebirds and tree swallows, and behavioral observations with video cameras placed within boxes.

Importantly, the birds did not preferentially select quiet boxes over noisy boxes, suggesting they do not recognize the reduction in habitat quality resulting from the noise," said study co-author Margaret Brittingham, professor of wildlife resources, College of Agricultural Sciences. "But both bluebirds and tree swallows nesting in noisy boxes spent less time incubating their eggs, had fewer eggs hatch and produced fewer young than their neighbors nesting in quiet boxes."

Natural gas is one of the most rapidly growing global energy sources, with continued expansion expected in shale gas development in particular. Compressor stations needed to pressurize gas and push it through pipelines to consumers -- often located in interior forests used by breeding birds -- may be depressing birds' reproduction in isolated forested areas.

"The loud, low-frequency noise emitted by natural gas compressor stations travels hundreds of yards into undisturbed areas," said co-author Julian Avery, associate research professor of wildlife ecology and conservation. "Because shale gas development often occurs in relatively undisturbed natural areas that provide important habitat for breeding birds, it is imperative that we develop plans to manage and mitigate noise."

The experiment, believed to be the first of its kind, was conducted at Penn State's Russell E. Larson Agricultural Research Center at Rock Springs, in central Pennsylvania. The study was unique because the researchers took extensive precautions to be sure they were assessing only the birds' reaction to the compressor noise and not other factors.

The design of the experiment allowed researchers to control for the confounding effects of both physical changes to the environment associated with compressor stations as well as the strong tendency for birds to return to the specific locations where they previously had bred.

CAPTION

The researchers were interested in how nests varied across the noise treatment and kept track of when nests were initiated and how many eggs were laid. These photos show how laying date and ultimate clutch size varied through the breeding season with panel A showing nests early in the season and panel B showing nests two to three weeks later during incubation.

CREDIT

Julian Avery, Penn State

Researchers established the 40 pairs of nest boxes to attract bluebirds and tree swallows to a site with no previous breeding population and immediately introduced shale gas compressor noise to half the boxes before birds returned to the region, while the other 40 boxes served as controls.

"We took a risk initiating the study -- we weren't sure these birds would find and occupy our boxes," Avery said. "We hoped that, 'if we build it, they will come.' Bluebirds likely had other nearby spots to nest, and the tree swallows were just returning from Central America. There was no guarantee they'd encounter our boxes."

The research was led by Danielle Williams, a master's degree student in wildlife and fisheries science, who currently is field coordinator for Purdue University's Hardwood Ecosystem Experiment.

Williams monitored video feeds from cameras placed within boxes to document changes in breeding behavior. She noted that there was no difference in clutch size -- eggs laid -- between noisy boxes and quiet boxes. Feeding behavior by the adults, known as provisioning, also was the same in both. However, in both species, she observed a reduction in incubation time, hatching success and fledging success -- the proportion of all eggs that fledged -- in noisy boxes compared to quiet boxes.

The findings, recently published in Ornithological Applications, demonstrate that compressor noise caused behavioral changes that led to reduced reproductive success for eastern bluebirds and tree swallows. The results indicate, the researchers said, that natural gas infrastructure can create an "equal-preference ecological trap," where birds do not distinguish between lower and higher quality territories, even when they incur reproductive costs.

Nest success -- the probability of fledging at least one young -- calculated from all nests that were initiated, was not affected by noise in either species studied, Brittingham pointed out.

"That suggests that noise did not increase rates of either depredation or abandonment but instead negatively impacted fitness through reduced hatching and fledging success," she said. "We never would have known that if we had not done this research."

CAPTION

Researchers took a risk initiating the study -- they weren't sure bluebirds like this one would find and occupy their boxes.

CREDIT

Julian Avery

Also involved in the research was acoustics expert Thomas Gabrielson, senior scientist, Penn State Applied Research Laboratory.

The U.S. Department of Agriculture's National Institute of Food and Agriculture, Penn State's Schreyer Institute for Teaching Excellence, the Association of Field Ornithologists and the NASA Pennsylvania Space Grant Consortium funded this research.

Giant predatory worms roamed the seafloor until 5.3 million years ago

The seafloor was inhabited by giant predatory worms until 5.3 million years ago

UNIVERSITY OF GRANADA

Research News

 

IMAGE: EUNICE APHRODITOIS (IMAGE COURTESY OF MS. CHUTINUN MORA) view more 

CREDIT: UNIVERSITY OF GRANADA

An international study in which the University of Granada participated--recently published in the journal Scientific Reports--has identified a new fossil record of these mysterious animals in the northeast of Taiwan (China), in marine sediments from the Miocene Age (between 23 and 5.3 million years ago)

These organisms, similar to today's Bobbit worm (Eunice aphroditois), were approximately 2 m long and 3 cm in diameter and lived in burrows

An international study in which the University of Granada (UGR) participated (recently published in the prestigious journal Scientific Reports) has revealed that the seafloor was inhabited by giant predatory worms during the Miocene Age (23-5.3 million years ago).

The scientists identified a new fossil record (indirect remains of animal activity such as, for instance, dinosaur tracks, fossilised droppings, insect nests, or burrows) linked to these mysterious animals, which are possible predecessors of today's Bobbit worm (Eunice aphroditois). Based on the reconstruction of giant burrows observed in Miocene-age marine sediments from northeast Taiwan (China), the researchers concluded that these trace fossils may have colonised the seafloor of the Eurasian continent about 20 million years ago.

Olmo Míguez Salas of the UGR's Department of Stratigraphy and Palaeontology (Ichnology and Palaeoenvironment Research Group) participated in the study, which was conducted as part of a project funded by the Taiwanese Ministry of Science and Technology (MOST, 2018) of which the researcher was a beneficiary.

Míguez Salas and the other researchers reconstructed this new fossil record, which they have named Pennichnus formosae. It consists of an L-shaped burrow, approximately 2 m long and 2-3 cm in diameter, indicating the size and shape of the organism-- Eunice aphroditois--that made the structure.

Bobbit worms hide in long, narrow burrows in the seafloor and propel themselves upward to grab prey with their strong jaws. The authors suggest that the motion involved in capturing their prey and retreating into their burrow to digest it caused various alterations to the structure of the burrows. These alterations are conserved in the Pennichnus formosae and are indicative of the deformation of the sediment surrounding the upper part of the burrow. Detailed analysis revealed a high concentration of iron in this upper section, which may, the researchers believe, indicate that the worms continuously rebuilt the opening to the burrow by secreting a type of mucus to strengthen the wall, because bacteria that feed on this mucus create environments rich in iron.

Although marine invertebrates have existed since the early Paleozoic, their bodies primarily comprise soft tissue and are therefore rarely preserved. The fossil record discovered in this study is believed to be the earliest known specimen of a subsurface-dwelling ambush predator.

Olmo Míguez Salas notes that this finding "provides a rare view of the behaviour of these creatures under the seafloor and also highlights the value of studying fossil records to understand the behaviour of organisms from the past."

ANOTHER STUDY ON PREHISTORIC SAND WORMS WAS DONE BY UBC RECENTLY

Ancient relic points to a turning point in Earth's history 42,000 years ago

Just like in The Hitchhiker's Guide to the Galaxy, the answer was 42

UNIVERSITY OF NEW SOUTH WALES

Research News

IMAGE: USING AN ANCIENT KAURI TREE LOG FROM NGĀWHĀ, NEW ZEALAND, SCIENTISTS HAVE DATED THE TIMING AND ENVIRONMENTAL IMPACTS OF THE LAST MAGNETIC POLE SWITCH. view more 

CREDIT: NELSON PARKER (WWW.NELSONSKAIHUKAURI.CO.NZ)

The temporary breakdown of Earth's magnetic field 42,000 years ago sparked major climate shifts that led to global environmental change and mass extinctions, a new international study co-led by UNSW Sydney and the South Australian Museum shows.

This dramatic turning point in Earth's history - laced with electrical storms, widespread auroras, and cosmic radiation - was triggered by the reversal of Earth's magnetic poles and changing solar winds.

The researchers dubbed this danger period the 'Adams Transitional Geomagnetic Event', or 'Adams Event' for short - a tribute to science fiction writer Douglas Adams, who wrote in The Hitchhiker's Guide to the Galaxy that '42' was the answer to life, the universe, and everything.

The findings are published today in Science.

"For the first time ever, we have been able to precisely date the timing and environmental impacts of the last magnetic pole switch," says Chris Turney, a professor at UNSW Science and co-lead author of the study.

"The findings were made possible with ancient New Zealand kauri trees, which have been preserved in sediments for over 40,000 years.

"Using the ancient trees we could measure, and date, the spike in atmospheric radiocarbon levels caused by the collapse of Earth's magnetic field."

While scientists already knew the magnetic poles temporarily flipped around 41-42,000 years ago (known as the 'Laschamps Excursion'), they didn't know exactly how it impacted life on Earth - if at all.

But the researchers were able to create a detailed timescale of how Earth's atmosphere changed over this time by analysing rings on the ancient kauri trees.

"The kauri trees are like the Rosetta Stone, helping us tie together records of environmental change in caves, ice cores and peat bogs around the world," says co-lead Professor Alan Cooper, Honorary Researcher at the South Australian Museum.

The researchers compared the newly-created timescale with records from sites across the Pacific and used it in global climate modelling, finding that the growth of ice sheets and glaciers over North America and large shifts in major wind belts and tropical storm systems could be traced back to the Adams Event.

One of their first clues was that megafauna across mainland Australia and Tasmania went through simultaneous extinctions 42,000 years ago.

"This had never seemed right, because it was long after Aboriginal people arrived, but around the same time that the Australian environment shifted to the current arid state," says Prof. Cooper.

The paper suggests that the Adams Event could explain a lot of other evolutionary mysteries, like the extinction of Neandertals and the sudden widespread appearance of figurative art in caves around the world.

"It's the most surprising and important discovery I've ever been involved in," says Prof. Cooper.

The perfect (cosmic) storm

The magnetic north pole - that is, the direction a compass needle points to - doesn't have a fixed location. It usually wobbles close to the North Pole (the northern-most point of Earth's axis) over time due to dynamic movements within the Earth's core, just like the magnetic south pole.

Sometimes, for reasons that aren't clear, the magnetic poles' movements can be more drastic. Around 41,000-42,000 years ago they swapped places entirely.

"The Laschamps Excursion was the last time the magnetic poles flipped," says Prof. Turney. "They swapped places for about 800 years before changing their minds and swapping back again."

Until now, scientific research has focused on changes that happened while the magnetic poles were reversed, when the magnetic field was weakened to about 28 per cent of its present-day strength.

But according to the team's findings, the most dramatic part was the lead-up to the reversal, when the poles were migrating across the Earth.

"Earth's magnetic field dropped to only 0-6 per cent strength during the Adams Event," says Prof. Turney.

"We essentially had no magnetic field at all - our cosmic radiation shield was totally gone."

During the magnetic field breakdown, the Sun experienced several 'Grand Solar Minima' (GSM), long-term periods of quiet solar activity.

Even though a GSM means less activity on the Sun's surface, the weakening of its magnetic field can mean more space weather - like solar flares and galactic cosmic rays - could head Earth's way.

"Unfiltered radiation from space ripped apart air particles in Earth's atmosphere, separating electrons and emitting light - a process called ionisation," says Prof. Turney.

"The ionised air 'fried' the Ozone layer, triggering a ripple of climate change across the globe."

Into the caves

Dazzling light shows would have been frequent in the sky during the Adams Event.

Aurora borealis and aurora australis, also known as the northern and southern lights, are caused by solar winds hitting the Earth's atmosphere.

Usually confined to the polar northern and southern parts of the globe, the colourful sights would have been widespread during the breakdown of Earth's magnetic field.

"Early humans around the world would have seen amazing auroras, shimmering veils and sheets across the sky," says Prof. Cooper.

Ionised air - which is a great conductor for electricity - would have also increased the frequency of electrical storms.

"It must have seemed like the end of days," says Prof. Cooper.

The researchers theorise that the dramatic environmental changes may have caused early humans to seek more shelter. This could explain the sudden appearance of cave art around the world roughly 42,000 years ago.

"We think that the sharp increases in UV levels, particularly during solar flares, would suddenly make caves very valuable shelters," says Prof. Cooper. "The common cave art motif of red ochre handprints may signal it was being used as sunscreen, a technique still used today by some groups.

"The amazing images created in the caves during this time have been preserved, while other art out in open areas has since eroded, making it appear that art suddenly starts 42,000 years ago."

Uncovering ancient clues

These findings come two years after a particularly important ancient kauri tree was uncovered at Ngāwhā, Northland.

The massive tree - with a trunk spanning over two and a half metres - was alive during the Laschamps.

"Like other entombed kauri logs, the wood of the Ngāwhā tree is so well preserved that the bark is still attached," says UNSW's Dr Jonathan Palmer, a specialist in dating tree-rings (dendrochronology). Dr Palmer studied cross sections of the trees at UNSW Science's Chronos 14Carbon-Cycle Facility.

Using radiocarbon dating - a technique to date ancient relics or events - the team tracked the changes in radiocarbon levels during the magnetic pole reversal. This data was charted alongside the trees' annual growth rings, which acts as an accurate, natural timestamp.

The new timescale helped reveal the picture of this dramatic period in Earth's history. The team were able to reconstruct the chain of environmental and extinction events using climate modelling.

"The more we looked at the data, the more everything pointed to 42," says Prof. Turney. "It was uncanny.

"Douglas Adams was clearly on to something, after all."

An accelerant like no other

While the magnetic poles often wander, some scientists are concerned about the current rapid movement of the north magnetic pole across the Northern Hemisphere.

"This speed - alongside the weakening of Earth's magnetic field by around nine per cent in the past 170 years - could indicate an upcoming reversal," says Prof. Cooper.

"If a similar event happened today, the consequences would be huge for modern society. Incoming cosmic radiation would destroy our electric power grids and satellite networks."

Prof. Turney says the human-induced climate crisis is catastrophic enough without throwing major solar changes or a pole reversal in the mix.

"Our atmosphere is already filled with carbon at levels never seen by humanity before," he says. "A magnetic pole reversal or extreme change in Sun activity would be unprecedented climate change accelerants.

"We urgently need to get carbon emissions down before such a random event happens again."

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This work was made possible by funding from an Australian Research Council Discovery Project Grant, support from Ngāpuhi iwi and Top Energy, the University of Waikato Radiocarbon Laboratory, and many other national and international partners.

Serbian Orthodox Church elects new head with close govt links

Issued on: 18/02/2021 

Porfirije (L) could have more moderate views on Kosovo, considered by the SPC as the cradle of the Serbian Orthodoxy, than his much older predecessor 

Oliver BUNIC AFP

Belgrade (AFP)

The Serbian Orthodox Church on Thursday elected as its new patriarch one of its youngest bishops known for his close ties to the Balkan country's political leaders.

Porfirije, bishop of Zagreb and Ljubljana, succeeds patriarch Irinej who died of coronavirus in November at the age of 90, a church statement said.

Analysts view Porfirije's election as the continuation of close ties between the Serbian Orthodox Church (SPC) and the country's political leaders led by President Aleksandar Vucic.

It is Vucic's choice as Porfirije is "someone who has for a long time been close to the authorities, close to Prime Minister Ana Brnabic and Vucic", Drasko Djenovic, an expert in religious affairs, told AFP.

The election of a new patriarch comes as Serbia and its former province of Kosovo, which proclaimed independence in 2008, are under pressure from new US President Joe Biden's administration and the European Union to relaunch a dialogue on normalisation of ties.

Porfirije could have more moderate views on Kosovo, considered by the SPC as the cradle of the Serbian Orthodoxy, than his much older predecessor, which suits Vucic, said Djenovic.

"Older bishops personify tough stances on Kosovo... the situation is completely different among young bishops who live in the 21st century."

Serbia and the SPC refuse to recognise the independence of ethnically Albanian-majority Kosovo.

The SPC was also strongly against Vucic's earlier suggestion on possible resolution of the Kosovo issue through land swaps.

Porfirije, born as Prvoslav Peric in northern Serbia, graduated from the Faculty of Theology in Belgrade and completed his postgraduate studies in Athens.

The polyglot bishop has a reputation as a moderate intellectual and has close ties with representatives of other religious groups.

For the election of its 46th patriarch, the SPC assembly known as Sabor, met for the first time in the crypt of the Church of Saint Sava, the biggest Orthodox temple in the Balkans.

The Sabor elected with a simple majority three candidates whose names were then sealed in three envelopes.

A monk then picked an envelope and thus "guided by the hand of God" elected a new SPC spiritual leader.

The new patriarch will be enthroned on Friday in Belgrade.

The influence of the SPC on Serbian society steadily grew after the fall of communism in the 1990s.

The great majority of Serbia's population of seven million people identify themselves as Orthodox Christians.

© 2021 AFP

Indigenous Guatemalans demand president's resignation


Issued on: 18/02/2021 - 

Rural Guatemalan protesters gathered in the capital to call for the resignation of the president and attorney general 

Johan ORDONEZ AFP


Guatemala City (AFP)

Thousands of rural Guatemalans marched on the capital Thursday to demand the resignation of President Alejandro Giammattei for what they claim was a weak response to the coronavirus pandemic and other mismanagement.

The protest, called by the Codeca rights group for indigenous peasant farmers, saw people congregate on the central square in Guatemala City waving flags and banners calling for an end to corruption and to the privatization of service industries such as electricity.

"The people have returned to the streets demanding justice and demanding the resignation of all the corrupt," leftwing MP Vicenta Jeronimo said at the protest.

Giammattei is criticized for his handling of the pandemic which has claimed over 6,100 lives so far out of 168,880 recorded infections in the impoverished Central American country of some 16 million people, as well as for alleged mismanagement of the economy.

The country hopes to receive coronavirus vaccines through the UN's Covax mechanism by month's end.

The protesters also sought the resignation of Attorney General Consuelo Porras, who they accuse of impeding the fight against government corruption, and called for an investigation into alleged killings of members of the Codeca organization.

Guatemala's indigenous population lives mainly in the west of the country and make up about 43 percent of the nation.

Rights groups say they suffer discrimination and marginalization, and in some communities poverty rates exceed 80 percent.

© 2021 AFP

Colombian military accused of 6,400 extrajudicial killings


Issued on: 18/02/2021 

A Colombian Army Black Hawk helicopter flies over an area where a FARC guerrillas attack took place in Cali, Colombia, in April 2015

 LUIS ROBAYO AFP/File


Bogota (AFP)

Colombia's military carried out at least 6,400 extrajudicial killings and presented them as combat deaths between 2002 and 2008, a number significantly higher than previously estimated, a special court said Thursday.

The court, called the Special Jurisdiction for Peace, is investigating crimes and atrocities committed during half a century of armed conflict between government troops and the Revolutionary Armed Forces of Colombia (FARC), Marxist rebels who laid down their weapons following a historic 2016 peace accord.

The tribunal, set up under the peace deal, described the killings as "illegitimate deaths presented as combat fatalities," which are known in military circles as "false positives."

Until last year, the public prosecutor's office had acknowledged 2,249 executions of civilians between 1988 and 2014 -- the majority of which were carried out between 2006 and 2008, during the presidency of Alvaro Uribe, the political mentor of current President Ivan Duque.

Although the military high command has always denied there was a systematic policy of declaring "false positives," some soldiers and officials have told the court that they were put under pressure by superiors to inflate the success of their military operations against rebels.

General Mario Montoya, who was the army commander at the time, is the highest ranking military figure to have testified before the court.

Despite witnesses blaming him for the killings, Montoya denies ordering the execution of civilians.

There are 2,140 military personnel currently under investigation over extrajudicial killings, which is less than one percent of the total number of troops operating in the army at that time, Montoya's lawyer Andres Garzon told AFP in 2020.

"That shows there was never a directive to the army to commit such atrocious acts," he said.

- 'Complicity' -

The court is looking into the worst rights abuses committed by guerrillas, paramilitaries and soldiers during the conflict.

Those who confess responsibility and compensate the victims can avoid prison time, but those who don't face up to 20 years in jail.

The court, though, has yet to convict anyone since it was set up in 2018.

It said most of the killings took place in the northwestern Antioquia department where soldiers and right-wing paramilitaries fought with left-wing rebels.

It said the IV Brigade of the army, which operated in the region, "could be responsible for 73 percent of the deaths identified in the department between 2000 and 2013."

Some remains of victims have been found in a cemetery in Antioquia thanks to statements made by members of the security forces, but the court said those "haven't been investigated."

According to Tania Parra, a lawyer representing soldiers who have confessed, Thursday's report shows there was "complicity" by authorities "to hide" the murders.

But she told AFP that while many investigations are opened, "either there's no result or .. they're cleared."

At least 20 of the 219 security forces personnel who have testified before the court are receiving protection after facing threats.

© 2021 AFP

Lebanese court removes judge from Beirut blast probe, activists slam ‘mockery of justice’

Issued on: 18/02/2021 - 

A Lebanese court on Feb. 18, 2021 dismissed a judge who had charged top politicians over the Aug. 4, 2020 Beirut port blast. 

© - AFP/File

Text by: FRANCE 24

A Lebanese court on Thursday dismissed a judge who had charged top politicians with negligence over last year's Beirut port explosion, infuriatingfamilies of victims who said it showed that the state would never hold powerful men to account.

Judge Fadi Sawan had led the investigation into the largest non-nuclear blast in history. In December, he charged three ex-ministers and the outgoing prime minister with negligence.

Two hundred people died in the August 4, 2020 blast when a huge stockpile of ammonium nitrate, stored unsafely for years, detonated at the capital's port. Thousands were injured and entire neighbourhoods destroyed.

On Thursday, the Lebanese Court of Cassation called for a new investigating judge to be appointed to lead the probe, nearly six months after it had started.

The court decided to take Sawan off the case after a request from two of the former ministers he charged.

A copy of the decision seen by Reuters cited "legitimate suspicion" over Sawan's neutrality, partly because his house was damaged in the blast which devastated much of the Lebanese capital.

The move will likely delay an investigation that has faced political pushback and has yet to yield any results.

'A mockery of justice'

Rights activists immediately condemned Thursday's ruling as the latest example of an entrenched political class placing itself above the law.

Sawan's removal "makes a mockery of justice and is an insult to the victims of the blast", Human Rights Watch researcher Aya Majzoub said.

The ruling showed "politicians are not subject to the rule of law", she added.

Following the announcement dozens of family members of people killed in the port blast rallied outside the main Beirut court house.

"Today you have killed us all over again! The investigation is over. We're back at square one," cried out one of the protesters, while others carried pictures of the victims.

Hariri, Hezbollah opposed indictment of ministers

On December 10, Sawan had issued charges against caretaker prime minister Hassan Diab and three former ministers for "negligence and causing death to hundreds", triggering outrage from politicians.

Premier-designate Saad Hariri and the powerful Shiite movement Hezbollah were among those to oppose the indictment.

Among those charged were former finance minister Ali Hassan Khalil and ex-public works minister Ghazi Zaiter, who accused Sawan of violating the constitution on the grounds of immunity and moved to have him removed from the case.

'Charade needs to end'

Lawyer and activist Nizar Saghieh said he needed to see the full court decision, but feared the worst.

"By refusing to be held accountable, the ministers and political class are drawing a red line in the investigation," he told AFP.

He said it was a typical pattern in Lebanon that "prevents any justice from being achieved".

Majzoub said: "More than six months later, we are back to square one."

"This charade needs to end ... We need an international, independent investigation as soon as possible."

Not a single politician detained

The probe into Lebanon's worst peace-time disaster has led to the detention of 25 people, from maintenance workers to the port's customs director, but not a single politician.

It has focused mainly on who was to blame for the fertiliser being left to languish unsafely at the port for more than six years, not how the ammonium nitrate ended up in Beirut.

On Monday, however, Sawan requested information from Lebanese security forces on three Syrian businessman thought to be behind the procurement of the fertiliser shipment that arrived on a dilapidated ship from Georgia in 2013.

Diab resigned after the port explosion, but the deeply divided political class has failed to agree on a new cabinet line-up.

Pressure from former colonial power France, whose President Emmanuel Macron has visited twice since the explosion, has failed to end the deadlock.

Lebanon desperately needs the government to launch reforms and unlock international aid to lift the country out of its worst financial crisis since the 1975-1990 civil war.

The value of the local currency has plummeted by more than 80 percent and around half the population live in poverty.

(FRANCE 24 with AFP, AP and REUTERS)