This is thanks to researchers at UNSW Sydney and their collaborators who have developed an innovative technique for sustainable ammonia production at scale.

Up until now, the production of ammonia has relied on high-energy processes that leave a massive global carbon footprint — temperatures of more than 400 ^oC and pressures exceeding 200 atmospheres that account for 2 per cent of the world’s energy and 1.8 per cent of its CO₂.

But the researchers have come up with a method that significantly enhances energy efficiency while making environmentally friendly ammonia economically feasible. The new technique eliminates the requirement for high temperatures, high pressure, and extensive infrastructure in ammonia production.

In a paper published recently in the journal Applied Catalysis B: Environmental, the authors show that the process they developed has enabled the large-scale synthesis of green ammonia by increasing its energy efficiency and production rate.

The foundation of this research, previously published by the same research group, has already been licensed to an Australian industry partner, PlasmaLeap Technologies, through the UNSW Knowledge Exchange program. It is set to be translated into the Australian agriculture industry, with a prototype already scaled up and ready for deployment.

The latest study follows on from the proof-of-concept research performed by the same UNSW research group three years ago with significant advances in energy efficiency and production rate in the process, thus improving commercial profitability.

The research also represents an opportunity to use green ammonia in the hydrogen transport market, as liquid ammonia (NH₃) can store more hydrogen in a smaller space than liquefied hydrogen (H₂), making the transportation of hydrogen energy more economical.

Net zero objectives

While the conventional process used for ammonia production is notably energy-intensive — relying heavily on fossil fuels as its primary energy and hydrogen sources — it has been instrumental in increasing crop yields and sustaining a growing global population.

Dr. Ali Jalili, the study’s leader and a former Australian Research Council DECRA Fellow at UNSW, says adopting a sustainable approach to ammonia production is crucial for global net zero objectives.

“Currently, the traditional method of producing ammonia — known as the Haber-Bosch process — accounts for 2.4 tonnes of CO₂ per tonne of ammonia, equivalent to approximately 2 per cent of global carbon emissions. Additionally, Haber-Bosch is economically viable only in large-scale and centralised facilities. Consequently, the transportation from these facilities to farms will increase the CO₂ emission by 50 per cent,” he says.

“Ammonia-based fertilisers are in critically short supply due to international supply chain disruptions and geopolitical issues, which impact our food security and production costs.

“This, together with its potential for hydrogen energy storage and transportation, makes ammonia key to Australia’s renewable energy initiatives, positioning the country among the leaders in renewable energy exports and utilisation.”

As well as addressing economic and logistical challenges associated with intermittent energy sources for cities or farms, Dr Jalili says to fully unlock its potential, it is “essential to establish a decentralised and energy-efficient production method that can effectively use surplus renewable electricity.”

When an earthquake strikes, smaller quakes known as aftershocks can continue to shake the area for days to years after the original earthquake occurred. These smaller quakes decrease over time and are part of the fault’s readjustment process following the original quake. While aftershocks are smaller in magnitude than the main shock, they can still damage infrastructure and impede recovery from the original earthquake.

“Some scientists suppose that contemporary seismicity in parts of stable North America are aftershocks, and other scientists think it’s mostly background seismicity,” said Yuxuan Chen, a geoscientist at Wuhan University and lead author of the study. “We wanted to view this from another angle using a statistical method.”

The study was published in the Journal of Geophysical Research: Solid Earth, AGU’s journal dedicated to research on the structure, evolution and deformation of the interior of our planet.

Regions near these historic earthquakes’ epicenters are still seismically active today, so it’s possible that some modern earthquakes could be long-lived aftershocks of past quakes. However, they could also be foreshocks that precede larger earthquakes or background seismicity, which is the normal amount of seismic activity for a given region.

According to the U.S. Geological Survey (USGS), there’s no way to distinguish foreshocks from background seismicity until a larger earthquake strikes, but scientists can still discern aftershocks. Thus, identifying the cause of modern earthquakes is important for understanding these regions’ future disaster risk, even if current seismic activity is causing little to no damage.

The team focused on three historic earthquake events estimated to range from magnitude 6.5-8.0: an earthquake near southeastern Quebec, Canada, in 1663; a trio of quakes near the Missouri-Kentucky border from 1811 to 1812; and an earthquake from Charleston, South Carolina, in 1886. These three events are the largest earthquakes in stable North America’s recent history — and larger quakes trigger more aftershocks.

The stable continental interior of North America is located far from plate boundaries and has less tectonic activity than regions close to plate boundaries, such as North America’s west coast. As a result, the three study areas don’t encounter earthquakes often, raising even more questions about the origins of their modern seismicity.

To figure out if some of today’s earthquakes are long-lived aftershocks, the team first needed to determine which modern quakes to focus their efforts on. Aftershocks cluster around the original earthquake’s epicenter, so they included earthquakes within a 250-kilometer (155-mile) radius of the historic epicenters. They focused on earthquakes that were greater than or equal to a magnitude of 2.5 because anything smaller than that is difficult to reliably record.

The team applied a statistical approach called the nearest neighbor method to USGS earthquake data to determine whether recent earthquakes were likely to be aftershocks or unrelated background seismic activity. Aftershocks occur close to the original quake’s epicenter and before the level of background seismicity has resumed, according to the USGS. Thus, scientists can use a region’s background seismicity and an earthquake’s location to link a quake back to a mainshock.

“You use the time, distance and the magnitude of event pairs, and try to find the link between two events — that’s the idea,” Chen said. “If the distance between a pair of earthquakes is closer than expected from background events, then one earthquake is likely the aftershock of the other.”

Susan Hough, a geophysicist with the USGS who was not involved in the study, mentions that the distance between epicenters is only one piece of the puzzle.

“In some respects, the earthquakes look like aftershocks if you look at the spatial distribution, but earthquakes could be tightly clustered for a couple of reasons,” Hough said. “One is that they’re aftershocks, but also you could have a process of creep going on that’s not part of an aftershock process. Exactly what their results mean is still open to question.”

Looking at the spatial distribution, the study found that the 1663 aftershock sequence near southeastern Quebec, Canada, has ended and modern seismicity in the area is unrelated to the old quake. However, the other two historic events may still be triggering aftershocks centuries later.

Near the Missouri-Kentucky border, the researchers found that around 30% of all earthquakes from 1980 to 2016 were likely aftershocks from the major earthquakes that struck the area between 1811 and 1812. And in Charleston, South Carolina, the team found around 16% of modern-day quakes were likely aftershocks from the earthquake of 1886. Thus, modern seismicity in these regions is likely attributable to both aftershocks and background seismicity.

“It’s kind of a mixture,” Chen said.

For assessing a region’s modern seismic risk, scientists monitor creep and background seismicity in addition to any aftershocks. The study found background seismicity to be the dominant cause of earthquakes in all three of the study regions, which could be a sign of continued strain accrual. Aftershock sequences weaken over time, but strain accrual can lead to larger earthquakes in the future. However, some faults can creep along without building up strain.

“To come up with a hazard assessment for the future, we really need to understand what happened 150 or 200 years ago,” Hough said. “So bringing modern methods to bear on the problem is important.”

Writing in the journal Nature Chemical Biology, a team led by chemist Ben Shen, Ph.D., described discovery of two new enzymes, ones with uniquely useful properties that could help in the fight against human diseases including cancer. The discovery, published last week, offers potentially easier ways to study and manufacture complex natural chemicals, including those that could become medicines.

The contribution of bacterial chemicals to the history of drug discovery is remarkable, said Shen, who directs the Natural Products Discovery Center at the institute, one of the world’s largest microbial natural product collections.

“Few people realize that nearly half of the FDA-approved antibiotics and anticancer drugs on the market are natural products or are inspired by them,” Shen said. “Nature is the best chemist to make these complex natural products. We are applying modern genomic technologies and computational tools to understand their fascinating chemistry and enzymology, and this is leading to progress at unprecedented speed. These enzymes are the latest exciting example.”

The enzymes the team discovered have a descriptive, if unwieldy, name. They are called “cofactorless oxygenases.” This means the bacterial enzymes pull oxygen from the air and incorporate it into new compounds, without requiring the typical metals or other cofactors to initiate the necessary chemical reaction.

This new way of synthesizing defensive substances would confer a survival advantage, enabling the organism to fend off infections or invaders. And because enzymes are to chemists what drill bits or saw blades are to a carpenter, they offer scientists new ways to create useful things, said the paper’s first authors, postdoctoral researchers Chun Gui, Ph.D., and Edward Kalkreuter, Ph.D.

Most immediately, the discovery of the enzymes, TnmJ and TnmK2, solves a lingering mystery of how a potential antibiotic and anticancer compound the Shen lab had first discovered in 2016, tiancimycin A, achieved such potency, Gui and Kalkreuter said.

The enzymes enable the bacteria to produce compounds for targeting and breaking up DNA, Gui said. This would be immensely useful in fighting off a virus or other germ — or killing cancer.

Tiancimycin A is being developed as part of a cancer-targeting antibody therapy. These types of combined antibody-drug therapeutics represent a rapidly growing new approach to fighting cancer. But a critical step to using tiancimycin A as an antibody’s payload is making enough to study it at a larger scale. That proved challenging.

“Even after we identified genes responsible for encoding tiancimycin A, several of the steps required to synthesize it could not be predicted,” Gui said. “The two enzymes described in the current study are highly unusual.”

Tiancimycin A was first found in a soil-dwelling bacteria, a type of Streptomyces from the strain collection at the Natural Products Discovery Center. To make its powerful chemical weapon, the organism had to solve a problem. It somehow had to break three highly stable carbon-carbon bonds and replace them with more reactive carbon-oxygen bonds. For a long time, the scientists couldn’t understand how the bacteria managed that feat.

Cracking the mystery involved finding other tiancimycin A-like natural product-producing bacteria among the institute’s Natural Products Discovery Center collection of 125,000 bacterial strains, and analyzing their genomes to search for the evolutionary hints.

The historic collection had long been housed in a pharmaceutical company’s basement, collected over decades following the discovery of penicillin in the scientific community’s hopeful rush to find the next great antibiotic. The collection did generate several historically important drugs through the years, including the tuberculosis antibiotic streptomycin and the organ transplant drug sirolimus. But the majority of the collection’s freeze-dried bacterial strains had rested in their glass vials, unexplored.

In 2018, Shen won a competition for the collection, so that it could be fully investigated in an academic setting, where it would be open to science. His team is now developing ways to study the strains, read their genomes and deposit the information into a searchable database for the scientific community to access. Modern genome sequencing and bioinformatics techniques are proving that there may be as many as 30 interesting gene clusters in each strain of bacteria they study, and many of them code for natural products never before documented by scientists, said Shen, who is a member of the UF Health Cancer Center.

The discovery of the new cofactorless enzymes is but the latest example of the chemical riches that lie within The Wertheim UF Scripps Institute’s collection, Shen said. Their discovery has sparked new excitement about further investigating the reasons the unique chemistry evolved, and the ways it may prove useful.

“This publication underscores how many surprises nature still has for us,” Shen said, “It can teach us much about fundamental chemistry and biology and provide us with the tools and inspiration we need to translate laboratory findings into medicines that impact society and address many problems faced by humanity.”

The study, published in the Personality and Social Psychology Bulletin, assessed 767 people over three times in May 2020. The researchers took a mixed-method approach that allowed them to look at several indicators of well-being while also asking people in an open-ended question to reflect on the role of pets from their point of view. Pet owners reported that pets made them happy. They claimed pets helped them feel more positive emotions and provided affection and companionship. They also reported negative aspects of pet ownership like being worried about their pet’s well-being and having their pets interfere with working remotely.

However, when their happiness was compared to nonpet owners, the data showed no difference in the well-being of pet owners and nonpet owners over time. The researchers found that it did not matter what type of pet was owned, how many pets were owned or how close they were with their pet. The personalities of the owners were not a factor.

“People say that pets make them happy, but when we actually measure happiness, that doesn’t appear to be the case,” said William Chopik, an associate professor in MSU’s Department of Psychology and co-author of the study. “People see friends as lonely or wanting companionship, and they recommend getting a pet. But it’s unlikely that it’ll be as transformative as people think.”

The researchers explored several reasons why there is not a difference between the well-being of pet owners and nonpet owners. One of them being that nonpet owners may have filled their lives with a variety of other things that make them happy.

In late September of this year, flash-flooding surged down neighborhood streets and subway stairways in New York City, as a historic rainfall led to canceled flights and closed roads and city officials urged people to stay at home or shelter in place. Some areas of the city saw up to 2.58 inches of rain in one day, nearly 50% more than the city sewer system’s maximum capacity, causing wastewater problems for many low-lying homes and businesses.

Intuitively, when an extreme weather event hits a city, the more residents it has, the larger number of people are affected. Currently, 83% of the United States population lives in urban settings, according to the U.S. Census. This number is expected to grow over the coming decades, rendering urban climate resilience extraordinarily important. As a result, many people have the impression that the growing sizes of cities are making weather extremes worse for the people who live there.

However, cities are designed and built by people. So, it stands to reason that if some methods of land development increase population exposures to extreme weather conditions, others might hold the potential to moderate or even reduce population exposures as the climate changes over the coming decades.

To explore this idea, University of Delaware researcher Jing Gao, assistant professor in the College of Earth, Ocean and Environment and a resident faculty member in the Data Science Institute, and colleague Melissa Bukovsky, associate professor in the Haub School of Environment and Natural Resources at the University of Wyoming, investigated how changes in urban land and population will affect future populations’ exposures to weather extremes under climate conditions at the end of the 21st century.

The researchers looked at urban areas across the continental United States, including cities large and small, with various development densities and in different climate regions. They used a data-driven model developed by Gao to predict how urban areas across the country will grow by 2100, based on development trends observed over the past 40 years. The research team considered how these urban land changes might affect weather extremes like heat waves, cold waves, heavy rainfalls and severe thunderstorms. They then analyzed how many people would be exposed to these extremes under different climate and urban development conditions at the end of the century.

The research team’s simulations showed that at the end of the 21st century, how a city is laid out or organized spatially, often called an urban land pattern, has the potential to reduce population exposures to future weather extremes, even for heat waves under very high urban expansion rates. Further, how the urban landscape is designed — meaning how buildings are clustered or dispersed and how they fit into the surrounding environment — seem to matter more than simply the size of a city. This is true even while climate change is increasing population exposures.

These findings apply to all cities, from large metropolitan areas like New York City to smaller towns in more rural contexts, such as Newark, Delaware.

“Regardless of the size of a city, well planned urban land patterns can reduce population exposures to weather extremes,” Gao said. “In other words, cities large and small can reduce their risks caused by weather extremes by better arranging their land developments.”

These findings differ from current common perceptions. For example, existing literature in this area has almost exclusively focused on limiting the amount of urban land development, Gao said.

In contrast, the new findings from this research encourage researchers and practitioners from a wide range of related fields to reconsider how cities are designed and built so that they can be in harmony with their regional natural surroundings and more resilient to potential climate risks over the long run.

Gao likened the effects of climate change and urban land patterns on extreme weather risks to the effects of a person’s diet and activity level on their risk for health problems. Properly designed urban land patterns, she said, are like physical exercises that work to counteract poor dietary choices, contributing to a reduced risk for disease, while helping a person become more fit in general.

“Carefully designed urban land patterns cannot completely erase increased population exposures to weather extremes resulting from climate change, but it can generate a meaningful reduction of the increase in risks,” Gao said.

And the cost to start is small, Gao said. No extravagant measure, such as leveling and rebuilding a large area at once, is required.

“Instead, when building new and renovating existing parts of a city, we should adjust our mindset to consider how the new development and renovation will change the way the city as a whole situates in its natural surroundings, and how the city and its surrounds can be one integrated human-environment system at large scales over the long run,” Gao said. “The key is to start adjusting how we think about development now.”

Next steps in the work

The researchers are working to identify specific characteristics about the spatial arrangement of a city that can make it more — or less — resilient to future weather extremes. Identifying these patterns can help guide development that is more sustainable in the face of increasing instances of extreme weather. Through their efforts, the research team hopes to provide actionable suggestions for how to design and build urban areas that reduce their residents’ exposures to weather extremes in the long run.

Importantly, the researchers emphasized that these characteristics will likely vary from region to region, now and as climate changes. For instance, what works in arid Phoenix, Arizona, will probably differ from what will work in humid New Orleans, Louisiana. Likewise, what might work today for a city could differ from what will work in the future, as climate conditions evolve.

“Eventually, we want our work to be directly useful to urban design and planning efforts, offering insights and tools for decision makers to influence long-term social and environmental well-being at scale,” Bukovsky said. “First, though, we need to identify what development patterns can improve various cities’ long-term climate resilience. We will continue collaborating in the future.”

Although previous researchers have collected water and microbial samples from the cave entrances and easily accessible sinkholes, the Northwestern-led team reached the deep, dark passageways of unlit waters to better understand what can survive inside this unique underground realm.

After analyzing the samples, the researchers noted a system rich with diversity, organized into distinct patterns. Similar to a stereotypical high school lunchroom, microbial communities within the cave system tend to cluster into well-defined cliques. But one family of bacteria (Comamonadaceae) acted as a popular social butterfly — appearing at nearly two-thirds of the “cafeteria tables.” The findings hint that Comamonadaceae is the ecological linchpin of the broader community.

The research was published late last week (Nov. 2) in the journal Applied and Environmental Microbiology.

“This is certainly the most expansive microbial survey across this part of the world,” said Northwestern’s Magdalena R. Osburn, who led the study. “These are incredibly special samples of underground rivers that are particularly difficult to obtain. From those samples, we were able to sequence the genes from microbial populations that live in these sites. This underground river system provides drinking water for millions of people. So, whatever happens with the microbial communities there has the potential to be felt by humans.”

A geobiology expert, Osburn is an associate professor of Earth and planetary sciences at Northwestern’s Weinberg College of Arts and Sciences. Northwestern alumnus Matthew Selensky led this project as a part of his dissertation when he was a graduate student in Osburn’s laboratory. Study co-author Patricia Beddows,professor of Earth and planetary sciences at Weinberg, led the cave-diving expedition and leveraged her decades of experience working on these caves. Other Northwestern co-authors include Andrew Jacobson, professor of Earth and planetary sciences, and former graduate student Karyn DeFranco, who focused on the geochemistry.

Located primarily in southeastern Mexico, the extensive Yucatán carbonate aquifer is pockmarked by numerous sinkholes leading to a complex web of underwater caves. Hosting a diverse, yet understudied microbiome, the underwater network contains areas of freshwater, seawater and mixtures of both. The system also includes a variety of zones — from pitch-black, deep pits with no direct openings to the surface to shallower sinkholes sparkling with sunlight.

“The Yucatan platform is essentially a Swiss cheese of cave conduits,” Osburn said. “We were curious which microbes are found together when we look across the whole system versus which microbes are found within one ‘neighborhood.'”

To explore this question, a team of cave divers collected 78 water samples from 12 individual sites within the cave system near the Caribbean coast in Quintana Roo, Mexico. The sample collection spanned from the Xunaan Ha system at the north end to inland and coastal portions of the Sac Actun system (including a distinctive, 60-meter-deep pit) to the Ox Bel Ha system to the south.

Back in a dive-shop-turned-science lab, researchers filtered cells out of each sample and analyzed its chemistry. Next, back at Northwestern, they identified microbial communities by sequencing their DNA. Then, Selensky developed a new computational program to perform network analysis on the data set. The resulting networks showed which species tend to live together. For each site, the researchers considered the environmental context of each microbial community, including cave type (pit or conduit), cave system, distance from the Caribbean coast, geochemistry and position in the water column.

Although water from the Gulf of Mexico flows into the Yucatán aquifer, the aquifer’s microbiome varies substantially from the nearby sea, the researchers found. The microbiomes also vary throughout the cave system — from cave to cave and from shallow water to deep water.

“The microbial communities form distinct niches,” Osburn said. “There is a varying cast of characters that seem to move around, depending on where you look. But when you look across the whole data set, there’s a core set of organisms that seem to be performing key roles in each ecosystem.”

Osburn and her team found that Comamonadaceae, a family of bacteria typically found in groundwater systems, lived in several niches. They also discovered that a deep, pit-like sinkhole with a surface opening (allowing sunlight to spill in) housed the most microbial communities — segregated into layers of distinct niches throughout the water column.

“It seems that Comamonadaceae performs slightly different roles in different parts of the aquifer, but it’s always performing a major role,” Osburn said. “Depending on the region, it has a different partner. Comamonadaceaeand its partners probably have some mutualistic metabolism, maybe sharing food.”