BOOK REVIEW

Geo-engineering: It’s probably not a good idea

October 30th, 2020, by Tim Radford

Iceland in 2010: The Eyjafjallajökull volcano erupts. Image: By anjči, via Wikimedia Commons

Skyseed: geo-engineering the planet might be humankind’s last desperate throw, says a tale by a geophysical hazard expert.

LONDON, 30 October, 2020 − There were always three objections to the technofix answer to climate change: that geo-engineeering wouldn’t work, that it would deliver unintended consequences that would be unpredictably distributed, and a third, rarely mentioned: that it might work all too well.

In Bill McGuire’s unexpected eco-thriller Skyseed: Hacking the Earth might be the last thing we ever do it works desperately well. Unexpected is a carefully chosen word: it’s no surprise that scientists can be good writers − I’ve argued elsewhere that they can be better writers than most writers − but the leap from factual analysis to lurid fable is a challenge.

Skyseed has what good thrillers always need, as well as geo-engineering: a world to save, characters with a bit of go in them, some plausible villains, fast-paced action, sustained tension, a big moment of reckoning and (let us be honest) as little preaching as possible.

The story is a simple one of global eco-collapse. Volcanoes are involved, and extreme weather, and ice, but not the outcome that McGuire (a volcanologist who for many years headed research into natural hazards) has spent a working lifetime warning about.

In this book, instead of taking the obvious route and abandoning fossil fuels as an energy source, a bullying, dishonest and unthinking American president, dependent on what is now called “dark money”, with help from a fawning British prime minister sorely in need of a trade deal, decides to contain global heating in a different way.

“The precise manner in this book in which civilisation perishes as a consequence of climate change is fortunately so far implausible”

The duo authorise a dangerous experiment in geo-engineering, under the cover of some so-called rain-making experiments during high-altitude military flights. That’s mistake one.

Mistake two is that they do it secretly. And they seem to think that a small army of global climate scientists − people whose career is based on sampling the stratospheric atmosphere and matching its chemistry with global temperature levels − won’t notice. And that if they do, these academic busybodies can be rubbed out without anyone else asking awkward questions.

Of course, things go wrong: horribly wrong, and it doesn’t take long for a trio of all-too human scientists, working separately and together, to tumble to the truth. As soon as they start to do so, sinister forces try to contain the secret. Our heroes survive, thanks to fortune, subterfuge and some help with the weather, and come back with the truth: don’t mess with geo-engineering.

In the course of this entertainment, the informed reader could play the game of spot-the-science: quite a lot, actually, but trailed racily and with just enough explanation to keep the story at stampede speed − advanced nano-engineering, upper atmosphere chemistry, volcanic discharges, the interplay of climate change on geological hazard, the advance of an ice front, and so on. You could both enjoy the story and learn a little more about how the planet works.

Not escapist

McGuire poses no great threat to the reputations of Len Deighton, Leslie Charteris and Ian Fleming, but who cares? Their heroes always survived, to begin a new adventure in each successive volume.

In Skyseed, whoever makes it to the last page doesn’t expect to survive for much longer, and − non-spoiler alert − McGuire cheerfully breaks that bit of bad news to the reader in the prologue. You know this one is going to end badly, before it even begins.

A declaration of interest: I know McGuire, professionally, and have done for many years. Another declaration: I can think of less readable books, by vastly better-known popular authors. And a third: the precise manner in this book in which civilisation perishes as a consequence of climate change is fortunately so far implausible.

That civilisation is threatened, and all too plausibly, by the inexorable increase of carbon dioxide in the atmosphere, unhappily is not. You could call this book a thriller. You could not call it escapist. − Climate News Network

Skyseed: The Book Guild, £8.99. By Bill McGuire

 

Study finds health trade-offs for wildlife as urbanization expands

Research on tree swallows suggests city living may offer advantages, but not without risks

OHIO STATE UNIVERSITY

Research News

 

IMAGE: OHIO STATE UNIVERSITY SCIENTISTS OBSERVED TREE SWALLOWS AS A MODEL SPECIES IN A STUDY ON THE EFFECTS OF URBANIZATION THAT FOUND CITY LIVING MAY OFFER WILDLIFE SOME ADVANTAGES, BUT NOT... view more 

CREDIT: JOSEPH CORRA, OHIO STATE UNIVERSITY

COLUMBUS, Ohio - City living appears to improve reproductive success for migratory tree swallows compared to breeding in more environmentally protected areas, a new five-year study suggests. But urban life comes with a big trade-off - health hazards linked to poorer water quality.

Researchers found that city-dwelling birds bred more nestlings because of warmer local temperatures. But they also had much higher levels of mercury in their blood - presumably from eating insects that spent their larval stages in contaminated water - than their counterparts breeding in less urban areas.

The study was conducted in central Ohio, where scientists observed tree swallows as a model species to assess their breeding success, diet and health measures in the context of varied temperatures, water quality and land use based on the location of their nests.

Despite those specifics, Ohio State University researchers consider the long-term study a harbinger of what's to come for all sorts of wildlife as urbanization increases while the climate continues to warm, and how land-use changes are likely to harm water quality and threaten biodiversity.

Urban land accounts for about 70 million acres in the contiguous United States, representing a 470% increase since 1945.

"With urbanization expanding worldwide, we are transforming the landscape. And this isn't going away," said lead author Ma�eika Sullivan, director of the Schiermeier Olentangy River Wetland Research Park at Ohio State. "My lab is looking at how urbanization affects multiple responses of ecosystems - what those changes are and quantifying them, but also seeing what this tells us about how we can manage and conserve ecosystems and wildlife in this context.

"Our task, knowing wildlife are using urban settings, is to think about ways to maximize benefits and minimize the risks. There's nature in cities. So how can we make our cities a little more wild?"

Sullivan, also an associate professor in Ohio State's School of Environment and Natural Resources, completed the work with graduate students Joseph Corra and Jeffry Hayes. The study was published online Nov. 15 in the journal Ecological Monographs.

Tree swallows are part of a guild of birds called aerial insectivores, which do all their dining on insects while in flight. Other species of swallows, as well as whip-poor-wills, nighthawks, swifts, martins and flycatchers, are also part of this group, and many of these species rely on ecosystems near water for food and habitat. Previous research has suggested that the number of North American birds has declined by about 3 billion since 1970, and the populations of some species of aerial insectivores have declined by over 50%.

The magnitude of that loss alone is a striking example of biodiversity loss, Sullivan said. But the reduction in this guild of birds can also affect the economy and the quality of human life.

"These migratory birds are really important not just in and of themselves, but because they're controlling insects - including pest insects that carry disease or damage agricultural crops. So they are very, very important in terms of how ecosystems function and stay in balance," he said.

For research purposes, tree swallows are also useful subjects because they are "cavity nesters" that flocked to the assortment of artificial nest boxes the team constructed along waterways in Columbus, some in developed zones and others in more forested areas.

From 2014-2018, the researchers observed tree swallows during their breeding season, most of May and June each year, also measuring their body weight and blood glucose and mercury levels and tracking how much of the birds' food source came from insects emerging from water or starting their pre-winged life on land. The scientists also monitored temperature and chemical water quality and quantified percentages of forested or wetland versus developed land at the breeding sites.

Egg-laying occurred significantly earlier (by almost eight days), the clutch sizes were larger, and the number of fledglings that left the nest was higher at the urban sites than at protected sites. This reproductive success was largely attributable to the temperature: The air was warmer in urban sites than in protected sites by an average of 3 degrees Fahrenheit, and city locations had fewer extremely cold days.

"We were looking at urbanization in two different ways - as a category of urban versus not urban, but also as gradients of urbanization. As the amount of urbanization increased, fledgling success increased," Sullivan said. "This tells us local climate is extremely important for reproductive success of tree swallows, and likely other insectivorous birds."

But that success came with potential health risks related to poorer water quality in urban areas. Insects that emerge from water constituted roughly a third of the tree swallows' diet, and those insects also tend to provide more nutrition and energy than terrestrial flying insects. But the river water in urban areas had higher levels of mercury - likely a proxy for other contaminants - and the adult birds' blood concentration of mercury was 482% higher in city-dwellers than in those who bred in protected sites.

"This is an important warning," Sullivan said. "There's a whole suite of environmental contaminants out there - pesticides, a lot of other heavy metals. So despite the advantage for breeding in these urban areas, there can be a trade-off in individual health."

These findings, and the implications for birds and other wildlife affected by growing urbanization, suggest that productive urban habitats should be factored in to future municipality planning, he said.

Some top considerations for insectivorous birds, as Sullivan sees it, would be establishing protected green ways, creating nesting habitats and structures to replace lost trees and other parts of the natural landscape, lowering the chances for contaminants to stream into waterways, and protecting wildlife food sources by reducing the use of pesticides and insecticides.

"If we had found that urbanization was negatively affecting tree swallows in all the different measures we used, that would be a very different story," Sullivan said. "But I see some rays of hope here."

###

This work was supported by the National Science Foundation, the Ohio Department of Natural Resources, the Ohio Water Development Authority and Ohio State.

Contact: Ma�eika Sullivan, Sullivan.191@osu.edu; 614-688-8402

Written by Emily Caldwell, Caldwell.151@osu.edu; 614-292-8152

A regular dose of nature may improve mental health during the COVID-19 pandemic

WILEY

Research News

 

IMAGE: A STUDY PUBLISHED IN ECOLOGICAL APPLICATIONS SUGGESTS THAT NATURE AROUND ONE'S HOME MAY HELP MITIGATE SOME OF THE NEGATIVE MENTAL HEALTH EFFECTS OF THE COVID-19 PANDEMIC. view more 

CREDIT: DR. SOGA

A study published in Ecological Applications suggests that nature around one's home may help mitigate some of the negative mental health effects of the COVID-19 pandemic.

An online questionnaire survey completed by 3,000 adults in in Tokyo, Japan, quantified the link between five mental-health outcomes (depression, life satisfaction, subjective happiness, self-esteem, and loneliness) and two measures of nature experiences (frequency of greenspace use and green view through windows from home).

More frequent greenspace use and the existence of green window views from the home were associated with increased levels of self-esteem, life satisfaction, and subjective happiness, as well as decreased levels of depression and loneliness.

"Our results suggest that nearby nature can serve as a buffer in decreasing the adverse impacts of a very stressful event on humans," said lead author Masashi Soga, PhD, of The University of Tokyo. "Protecting natural environments in urban areas is important not only for the conservation of biodiversity, but also for the protection of human health."

Trees and green roofs can help reduce the urban heat island effect, finds a new study

UNIVERSITY OF SURREY

Research News

Air pollution experts from the University of Surrey have found that green infrastructure (GI), such as trees, can help reduce temperatures in many of Europe's cities and towns.

An urban heat island is an urban area that is significantly warmer than its surrounding rural areas. The temperature difference is typically larger at night than during the day.

With the UK government pledging to build 300,000 new homes every year, it is feared that many of the country's towns and cities will experience an increase in temperature brought about by more vehicles and building activity.

In a paper published by Environmental Pollution, experts from Surrey's Global Centre for Clean Air Research (GCARE) modelled how a UK town would be affected if its urban landscape included different types of GI.

The study focused on simulating temperature increases in the town of Guildford, UK, under different GI cover (trees, grassland and green roofs). The team adopted widely-used computer modelling systems that found that 78 per cent of Guildford was covered by grassland and trees.

The research team set out to investigate five scenarios:

• What is the status quo with the current GI?
• What would happen if the town had no GI?
• What would happen if you replaced the current GI with only trees?
• What would happen if you replaced the current GI with only green roofs?
• What would happen if you replaced the current GI with only grassland?

The GCARE team found that trees are the most effective form of GI and the results showed that Guildford would be 0.128oC cooler if trees replaced all forms of GI in the town.

The team also found that trees are the best solution for the reduction in temperature spikes because they can better shade surfaces and influence aerodynamic mixing of air in the atmosphere caused by enhanced turbulence.

Professor Prashant Kumar, Director of GCARE at the University of Surrey, said: "As policymakers and political leaders rightly look to solve the nation's housing crisis, it is vitally important that they consider how this influx of new urban infrastructure will impact our environment and our planet.

"I hope that our study will give decision-makers the information they need when they are deciding which green infrastructure to establish in our communities. Our results suggest that, given a choice, trees are the most effective at reducing the urban heat island effect that many of our towns face."

###

Note to editors

This work was supported by the H2020 iSCAPE project (Grant Agreement #689954) and the EPSRC INHALE project (EP/T003189/1). It builds upon previous GCARE research into proposed modelling methods for evaluating the impact of green infrastructure and the impact of GI on air pollutant dispersion at an urban scale under different GI scenarios, and nexus between green infrastructure, air pollution and human health.

Reference
Tiwari, A., Kumar, P., Kalaiarasan, G., Ottosen, T.B., 2020. The impacts of existing and hypothetical green infrastructure scenarios on urban heat island formation. Environmental Pollution, 115898.

Research on environmental history: 330-year-old poplar tree tells of its life

An epigenetic ageing clock in trees

TECHNICAL UNIVERSITY OF MUNICH (TUM)

Research News

IMAGE: USING TREES AS A MODEL, RESEARCHERS OF THE TUM AND OF THE UNIVERSITY OF GEORGIA, USA, HAVE SHOWN FOR THE FIRST TIME THAT EPIMUTATIONS ACCUMULATE CONTINUOUSLY THROUGHOUT PLANT DEVELOPMENT AND... view more 

CREDIT: ROBERT SCHMITZ

Epigenetic marks do not change the DNA sequence but can affect the activity of genes. "Although in animals, including humans, these marks are believed to be completely reset in gametes, in plants, they can be stably inherited for many generations," says Frank Johannes, Professor of Population Epigenetics and Epigenomics at the Technical University of Munich (TUM), whose research team has been trying to understand how epimutations arise in plant genomes, how stable they are across generations, and whether they can affect important plant characteristics.

Trees are natural epimutation accumulation systems

"Given their extraordinary longevity, trees act as natural epimutation accumulation systems, and therefore offer unique insights into epigenetic processes over long time-scales," says Professor Johannes. Together with co-senior author Professor Robert J. Schmitz (University of Georgia, USA), who is also a Hans Fisher Fellow at the TUM-IAS, he recently published two companion papers on this topic.

In their studies, the team focused on a 330 year-old poplar tree. By comparing DNA methylation (an important epigenetic mark) of leaves from different branches of the tree, they were able to show that epimutations accumulate continuously as a function of the tree's age. The researchers found that the further apart two leaves are from each other, in terms of developmental time, the more dissimilar their DNA methylation patterns are. From this, the researchers were able to conclude that the rate of somatic epimutations is about 10,000 times higher than the genetic mutation rate in this same tree.

An epigenetic ageing clock in trees?

This discovery led to the intriguing insight that epimutations can serve as a kind of molecular clock to determine the age of a tree. "Only some branches had been dated by counting tree rings, but unfortunately not the main stem. We really needed this information for our analysis, so we decided to treat the total age of the tree as an unknown parameter and let the DNA methylation data of the leaves tell us how old the tree is. This gave an estimate of about 330 years," says Professor Johannes.

The estimate later turned out to be consistent with diameter-based dating of the main stem and with other information on the life history of this particular tree. "This was the first indication that there is something like an epigenetic clock in trees."

A window into the past

The team around Prof. Johannes is now pursuing the question whether environmental changes that trees experience over their long life-times leave epigenetic signatures that can be read and interpreted to learn something about their past.

"Our goal is to integrate historical environmental data with our epigenetic work. We think this may offer a window into the past which can help us to understand how trees have dealt with specific environmental challenges such as droughts and temperature fluctuations. This type of information may be useful when considering the future, particularly in light of global climate change."

CAPTION

Researchers want to correlate data of the environmental history of trees with their epigenetic work to offer a window into the past which can help to understand how trees have dealt with specific environmental challenges such as droughts and temperature fluctuations.

More Information

In an ongoing follow-up project, Frank Johannes is working together with Hans Pretzsch, Professor of Forest Growth and Yield Science (https://www.waldwachstum.wzw.tum.de/en/) at the TUM. His department is heading a European beech experiment in the Steigerwald in Central Germany, where individual trees have been closely observed since their first planting in 1870. Detailed growth and climate data are available for these tress. They have now been investigating if and how the developmental history of these trees can be reconstructed using epigenetic measurements.

CAPTION

Poplar trees tell scientists of their life

Geoscientists discover Ancestral Puebloans survived from ice melt in New Mexico lava tubes

A lava tube in the El Malpais National Monument yields centuries-old insights of survival in the face of harsh climate change

UNIVERSITY OF SOUTH FLORIDA (USF INNOVATION)

Research News

 

IMAGE: ICE DEPOSIT AT THE EL MALPAIS NATIONAL MONUMENT IN NEW MEXICO. view more 

CREDIT: UNIVERSITY OF SOUTH FLORIDA

TAMPA, Fla. (Nov. 18, 2020)- For more than 10,000 years, the people who lived on the arid landscape of modern-day western New Mexico were renowned for their complex societies, unique architecture and early economic and political systems. But surviving in what Spanish explorers would later name El Malpais, or the "bad lands," required ingenuity now being explained for the first time by an international geosciences team led by the University of South Florida.

Exploring an ice-laden lava tube of the El Malpais National Monument and using precisely radiocarbon- dated charcoal found preserved deep in an ice deposit in a lava tube, USF geosciences Professor Bogdan Onac and his team discovered that Ancestral Puebloans survived devastating droughts by traveling deep into the caves to melt ancient ice as a water resource.

Dating back as far as AD 150 to 950, the water gatherers left behind charred material in the cave indicating they started small fires to melt the ice to collect as drinking water or perhaps for religious rituals. Working in collaboration with colleagues from the National Park Service, the University of Minnesota and a research institute from Romania, the team published its discovery in "Scientific Reports."

The droughts are believed to have influenced settlement and subsistence strategies, agricultural intensification, demographic trends and migration of the complex Ancestral Puebloan societies that once inhabited the American Southwest. Researchers claim the discovery from ice deposits presents "unambiguous evidence" of five drought events that impacted Ancestral Puebloan society during those centuries.

"This discovery sheds light on one of the many human-environment interactions in the Southwest at a time when climate change forced people to find water resources in unexpected places," Onac said, noting that the geological conditions that supported the discovery are now threatened by modern climate change.

"The melting cave ice under current climate conditions is both uncovering and threatening a fragile source of paleoenvironmental and archaeological evidence," he added.

Onac specializes in exploring the depths of caves around the world where ice and other geological formations and features provide a window to past sea level and climate conditions and help add important context to today's climate challenges.

Their study focused on a single lava tube amid a 40-mile swatch of treacherous ancient lava flows that host numerous lava tubes, many with significant ice deposits. While archaeologists have suspected that some of the surface trails crisscrossing the lava flows were left by ancient inhabitants searching for water, the research team said their work is the earliest, directly dated proof of water harvesting within the lava tubes of the Southwest.

The study characterizes five drought periods over an 800-year period during which Ancestral Puebloans accessed the cave, whose entrance sits more than 2,200 meters above sea level and has been surveyed at a length of 171 meters long and about 14 meters in depth. The cave contains an ice block that appears to be a remnant of a much larger ice deposit that once filled most of the cave's deepest section. For safety and conservation reasons, the National Park Service is identifying the site only as Cave 29.

In years with normal temperatures, the melting of seasonal ice near cave entrances would leave temporary shallow pools of water that would have been accessible to the Ancestral Puebloans. But when the ice was absent or retreated in warmer and dryer periods, the researchers documented evidence showing that the Ancestral Puebloans repeatedly worked their way to the back of the cave to light small fires to melt the ice block and capture the water.

They left behind charcoal and ash deposits, as well as a Cibola Gray Ware pottery shard that researchers found as they harvested a core of ancient ice from the block. The team believes the Ancestral Puebloans were able to manage smoke within the cave with its natural air circulation system by keeping the fires small.

The discovery was an unexpected one, Onac said. The team's original goal in its journey into the lava tube was to gather samples to reconstruct the paleoclimate using ice deposits, which are slowly but steadily melting.

"I have entered many lava tubes, but this one was special because of the amount of charcoal present on the floor in the deeper part of the cave," he said. "I thought it was an interesting topic, but only once we found charcoal and soot in the ice core that the idea to connect the use of ice as a water resource came to my mind."

Unfortunately, researchers are now racing against the clock as modern climate conditions are causing the cave ice to melt, resulting in the loss of ancient climate data. Onac said he recently received support from the National Science Foundation to continue the research in the lava tubes before the geological evidence disappears.

###

Joining in the exploration and research were Dylan S. Parmenter, whose master's degree at USF was on the topic and is now a doctoral student at the University of Minnesota, Steven M. Baumann and Eric Weaver of the National Park Service, and Tiberiu B. Sava of the Horia Hulubei National Institute for Physics and Nuclear Engineering in Romania. The research was funded by the National Park Service and the National Science Foundation.

Teton range glacial ice may have persisted in a dormant state during early Holocene warming

Alpine glacier resilience and Neoglacial fluctuations linked to Holocene snowfall trends in the western US

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

Research News

 

A continuous 10,000-year record of alpine glacier fluctuations in Wyoming's Teton Range suggests that some glacial ice in the western U.S. persisted in a reduced, essentially dormant state during periods of early Holocene warming. The findings challenge the paradigm that all Rocky Mountain glaciers completely disappeared during these warm, dry conditions, instead indicating that they may have taken the form of smaller glaciers covered by debris or caked with rocks, which insulated the lingering ice from the heat. This insight may help scientists better understand how glaciers in the region may respond to future warming. "The long-term survival of glacial ice through warm conditions highlights the potential role of debris-covered glaciers and/or rock glaciers to continue providing ecosystem services into the future, despite unfavorable climatic conditions," says Darren Larsen, the lead author of the study. Retreating glaciers are a hallmark of modern climate change, but due to an incomplete glacial record, little is known about how western U.S. glaciers responded to temperature and precipitation changes thousands of years ago. To construct a continuous record, Larsen and colleagues sampled sediment cores from two lake basins in the Tetons - Delta Lake, a glacial lake basin that provided a complementary record of glacier activity, and other nearby lakes including Surprise Lake, a nonglacial lake basin that provided a record of climate variability. By using accelerator mass spectrometry radiocarbon dating, the researchers developed composite rock layer sequences that documented changes in the glaciers as they endured shifts in climate over ten millennia. While sediment flux and meltwater from the Teton Glacier appeared to decrease during a warm period between about 10,000 and 6,300 years ago, Delta Lake sediments maintained distinctly glacial characteristics that suggest glacial ice remained.

Alzheimer's disease drug may help fight against antibiotic resistance

UNIVERSITY OF QUEENSLAND

Research News

 

IMAGE: UQ'S DR DAVID DE OLIVEIRA IN THE LAB, TESTING THE EFFICACY OF PBT2 IN DISRUPTING AND KILLING ANTIBIOTIC-RESISTANT GRAM-NEGATIVE BACTERIA. view more 

CREDIT: THE UNIVERSITY OF QUEENSLAND

An experimental Alzheimer's disease treatment is proving effective at treating some of the most persistent, life-threatening antibiotic-resistant bacteria.

Researchers from The University of Queensland, The University of Melbourne and Griffith University have discovered that the drug called PBT2 is effective at disrupting and killing a class of bacteria - known as Gram-negative bacteria - that cause infections such as pneumonia, bloodstream infections and meningitis.

UQ's Professor Mark Walker said the metal transport drug may offer a last line of defence against some of the world's most difficult to treat superbugs.

"The emergence of antibiotic-resistant superbugs is an urgent threat to human health, undermining the capacity to treat patients with serious infection," Professor Walker said.

"Alternative strategies to treat such multi-drug resistant bacteria are urgently needed.

"Led by UQ's Dr David De Oliveira, our team hypothesised that, by using this experimental Alzheimer's treatment to disrupt the metals inside these bacteria, we would also disrupt their mechanisms of antibiotic resistance.

"This was shown to be the case, with the Alzheimer's drug - combined with the antibiotic polymyxin - successfully tackling antibiotic-resistant superbugs like Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Escherichia coli."

Griffith University's Professor Mark von Itzstein AO from the Institute for Glycomics said the new treatment was effective, and offered a range of other benefits.

"Based on its use as an experimental Alzheimer's treatment, there's been a significant amount of solid science done on this drug already," Professor von Itzstein said.

"We know, for example, that clinical studies of PBT2 show that it is safe for use in humans.

"And, given that we've been able to combine it with the antibiotic polymyxin to treat polymyxin-resistant bacteria, we may be able to make other now-ineffective antibiotics become effective again for treating infectious diseases.

"This could resharpen, so to speak, some of the weapons we thought we'd lost in our fight against antibiotic-resistant bacteria."

The University of Melbourne's Associate Professor Christopher McDevitt, from the Peter Doherty Institute for Infection and Immunity (Doherty Institute), said the drug had already proved effective beyond the petri dish.

"Animal studies show that the combination of polymyxin and PBT2 kills polymyxin-resistant bacteria, completely clearing any infection," Associate Professor McDevitt said.

"Hopefully in the not-too-distant future people will be able to access this type of treatment in the clinic.

"New techniques are critical in addressing this building threat to human health, and this treatment is an additional weapon in our arsenal to fight the accelerating threat of antibiotic resistance.

"If these new solutions aren't developed, it's estimated that by 2050, antimicrobial-resistant bacteria will account for more than 10 million deaths per year.

"This new treatment could help turn the tide on antibiotic resistance."

The study is published in Science Translational Medicine (DOI: 10.1126/scitranslmed.abb3791).

Antibiotic resistance genes in three Puerto Rican watersheds after Hurricane Maria

AMERICAN CHEMICAL SOCIETY

Research News

IMAGE: ARGS WERE LOWER IN NUMBER AND LESS DIVERSE IN THIS RURAL PUERTO RICAN WATERSHED AFTER HURRICANE MARIA THAN IN AN URBAN WATERSHED. view more 

CREDIT: MARIA VIRGINIA RIQUELME

In the aftermath of Hurricane Maria, a category 5 hurricane that made landfall in September 2017, flooding and power outages caused some wastewater treatment plants (WWTPs) to discharge raw sewage into waterways in Puerto Rico. Six months later, researchers monitored antibiotic resistance genes (ARGs) in three Puerto Rican watersheds, finding that the abundance and diversity of ARGs were highest downstream of WWTPs. They report their results in ACS' Environmental Science & Technology.

Flooding can result in contamination of waterways with untreated human waste, and in turn, fecal and pathogenic bacteria. Previous research has linked this contamination to the emergence of antibiotic-resistant bacteria. To help monitor the spread of these potentially harmful microbes in waterways, Benjamin Davis, Maria Virginia Riquelme, Amy Pruden and colleagues wanted to detect and quantify bacterial genes that confer antibiotic resistance in three Puerto Rican watersheds post-Hurricane Maria.

The researchers used a method called shotgun metagenomics DNA sequencing to detect ARGs in river water samples from three watersheds, including samples upstream and downstream of three WWTPs. The researchers found that the abundance and diversity of total ARGs, in particular those that confer resistance to clinically important aminoglycoside and β-lactam antibiotics, were higher downstream of WWTPs compared with upstream. The total ARG abundance was higher in samples from an urban high-impact watershed than from the two other watersheds, which had less human influence. Also, two anthropogenic antibiotic resistance markers -- DNA sequences associated with human impacts to the watershed -- correlated with the abundance of a distinct set of ARGs. Although baseline levels of ARGs in these Puerto Rican watersheds prior to Hurricane Maria are unknown, surveillance methodologies like these could be used to assess future impacts of major storms on the spread of antibiotic resistance, the researchers say.

###

The authors acknowledge funding from the National Science Foundation and the U.S. Department of Agriculture.

The paper's abstract will be available on November 18 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acs.est.0c05567

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Starved, stuffed and squandered: Consequences of decades of global nutrition transition

POTSDAM INSTITUTE FOR CLIMATE IMPACT RESEARCH (PIK)

Research News

 

Just a handful of rice and beans - a part of our world is starved. Hawaiian Pizza and ice-cream - another part of our world is stuffed, throwing away food every day. This gap is likely to worsen, while food waste will increase and pressure on the environment will go up, a new study shows. Researchers from the Potsdam Institute for Climate Impact Research (PIK) assessed the consequences if the current nutrition transition, from scarce starch-based diets towards processed foods and animal products, continues - the calculations combine, for the first time, estimates for under- and overweight, food composition and waste. Their findings provide a startling look ahead: By 2050, more than 4 billion people could be overweight, 1.5 billion of them obese, while 500 million people continue to be underweight.

"If the observed nutrition transition continues, we will not achieve the United Nations goal of eradicating hunger worldwide," explains Benjamin Bodirsky from PIK, lead author of the study just published in Scientific Reports. "At the same time, our future will be characterized by overweight and obesity of mind-blowing magnitude." By 2050, 45 percent of the world's population could be overweight and 16 percent obese - compared to about 29 and 9 percent in 2010. This development is due to the insufficient global distribution of food as well as to the shift from scarcely processed plant-based diets towards unbalanced, affluent diets, where animal protein, sugar and fat displace whole grains and pulses.

And that's not all as Bodirsky underlines: "The increasing waste of food and the rising consumption of animal protein mean that the environmental impact of our agricultural system will spiral out of control. Whether greenhouse gases, nitrogen pollution or deforestation: we are pushing the limits of our planet - and exceed them."

Food systems as driver for greenhouse gas emissions

Crop and grazing land for food production cover about one third of the global land area; our food system is responsible for up to a third of global greenhouse gas emissions. The study projects that - if current trends continue - global food demand will increase by about 50% between 2010 and 2050, the demand for animal products like meat and milk will approximately double, a development that requires more and more land.

"Using the same area of land, we could produce much more plant-based food for humans than animal-based food," explains co-author Alexander Popp, head of PIK's Land Use Management Research Group. "To put it in a very simplistic way: If more people eat more meat, there's less plant-based food for the others - plus we need more land for food production which can lead to forests being cut down. And greenhouse gas emissions rise as a consequence of keeping more animals."

Global food demand: distribution and education are at the heart of the problem

The study provides a first-of-its kind, consistent long-term overview of a continued global nutrition transition from 1965 to 2100, using an open-source model that forecasts how much of food demand can be attributed to factors like population growth, ageing, increasing height, growing body mass index, declining physical activity and increasing food waste. Co-author Prajal Pradhan from PIK explains: "There is enough food in the world - the problem is that the poorest people on our planet have simply not the income to purchase it. And in rich countries, people don't feel the economic and environmental consequences of wasting food." But redistribution alone would not be sufficient, as actually both the poor and the rich eat poorly: There is a lack of knowledge about a healthy way of life and nutrition.

How to trigger an appetite for change?

"Unhealthy diets are the world's largest health risks," co-author Sabine Gabrysch, head of PIK's Research Department on Climate Resilience explains. "While many countries in Asia and Africa currently still struggle with undernutrition and associated health problems, they are increasingly also faced with overweight, and as a consequence, with a rising burden of diabetes, cardiovascular disease and cancer," she adds. The study could provide valuable orientation about the potential development pathway of different countries and regions. It could also support much-needed pro-active policies for a qualitative transition towards sustainable and healthy diets.

Sabine Gabrysch concludes: "We urgently need political measures to create an environment that promotes healthy eating habits. This could include binding regulations that limit the marketing of unhealthy snacks and promote sustainable and healthy meals in schools, hospitals and canteens. A stronger focus on nutrition education is also key, from early education in kindergarten to counseling by medical doctors and nurses. What we eat is of vital importance - both for our own health and that of our planet."

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Article:
Benjamin Leon Bodirsky, Jan Philipp Dietrich, Eleonora Martinelli, Antonia Stenstad, Prajal Pradhan, Sabine Gabrysch, Abhijeet Mishra, Isabelle Weindl, Chantal Le Mouël, Susanne Rolinski, Lavinia Baumstark, Xiaoxi Wang, Jillian L. Waid, Hermann Lotze?Campen, Alexander Popp (2020): The ongoing nutrition transition thwarts long-term targets for food security, public health and environmental protection.
Scientific Reports [DOI: 10.1038/s41598-020-75213-3]

Weblink to the article once it is published:
http://www.nature.com/articles/s41598-020-75213-3