Making green energy the default choice can help tackle climate change, study finds

UNIVERSITY OF WARWICK

Research News

 

Researchers studying the Swiss energy market have found that making green energy the default option for consumers leads to an enduring shift to renewables and thus has the potential to cut CO2 emissions by millions of tonnes.

The study, published today in Nature Human Behaviour, investigated the effect of changes in the Swiss energy market that presented energy from renewable sources as the standard option for consumers - the 'green default.'

Both business and private customers largely accepted the default option, even though it was slightly more expensive, and the switch to green sources proved a lasting one.

Professor Ulf Liebe (University of Warwick), Doctor Jennifer Gewinner and Professor em. Andreas Diekmann (both ETH Zurich) analysed data from two Swiss energy suppliers who between them supplied around 234,000 households and 9,000 businesses in urban and rural areas.

Both companies restructured their products to offer a choice between conventional power, renewable power and "renewable plus," one company in 2009 and the other in 2016. Consumers were assigned the renewable package unless they opted out, a behavioural mechanism known to have success in a range of settings.

• Supplier A saw a drop in private customers on the conventional tariff from 97 per cent to 15 per cent following introduction of the green default. By year 6, 80 per cent of households were still on the green tariff

• For SMEs, the fall was smaller - from 97 per cent to 23 per cent, with 71 per cent still on the green option in year 6.

• Supplier B saw similar results, with a change from 98.8 per cent of households using conventional energy to just 11 per cent after the introduction of the green default.

• For SMEs supplied by company B, the fall was from 99.3 per cent to 15.3 per cent on the non-renewable package.

Further analysis of customer data in the household sector showed that women were around 6 per cent more likely than men to accept the green default, while women business owners were 8 per cent more likely to stick with the renewable package.

It is sometimes argued that the introduction of green energy defaults leads to an increase in energy use - because the energy is 'clean' consumers are more relaxed about using it. Analysis of six years of energy consumption data showed no evidence of this.

Commenting on these results, Professor Liebe said: "Our study shows that 'green defaults' have an immediate, enduring impact and as such should be part of the toolkit for policymakers and utility companies seeking to increase renewable energy consumption, not only among household customers but also in the business sector."

Large green default effects can considerably reduce CO2 emissions in countries with high fossil fuel share in their energy mix. Taking Germany as a case study and assuming a default effect of 80% in the household sector, the study calculated a CO2 reduction of about 45 million tonnes and a positive welfare effect of €1,240 million. While the impact of default effects can be massive, the exact CO2 reduction figures and welfare gains depend on the CO2 emission factor and social cost of carbon.

###

NOTES

Liebe, U., Gewinner, J., Diekmann, A. Large and persistent effects of green energy defaults in the household and business sectors. Nat Hum Behav 5 (2021). https://dx.doi.org/10.1038/s41562-021-01070-3. This link will go live after the embargo lifts.

The full listing of authors and their affiliations for this paper is as follows:

Ulf Liebe: University of Warwick, University of Warwick

Jennifer Gewinner: ETH Zurich

Andreas Diekmann: ETH Zurich, University of Leipzig

The following funding acknowledgements from the authors appear at the end of the paper:

Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (Swiss National Science Foundation)

 

Firefly tourism takes flight, sparking wonder and concern

First comprehensive review on the growing global phenomenon of firefly tourism

TUFTS UNIVERSITY

Research News

 

IMAGE: IN NORTH CAROLINA USA, MALE BLUE GHOST FIREFLIES (PHAUSIS RETICULATA) GLOW WHILE SEARCHING FOR MATES. THEIR FLIGHTLESS FEMALES ARE HIGHLY VULNERABLE TO TRAMPLING, AS THEY REMAIN HIDDEN ON THE FOREST... view more 

CREDIT: SPENCER BLACK

Firefly beetles rank among the world's most charismatic creatures, with luminous courtship displays that have now turned them into a popular attraction for wildlife tourists. In the first comprehensive review of firefly tourism, published in the journal Conservation Science and Practice, an international team of biologists led by a Tufts University researcher, reveal that an estimated 1 million people now travel each year to witness bioluminescent performances starring some two dozen firefly species around the world.

But the authors also point out that while this unique, insect-based tourism can bring economic, social, and psychological benefits to local communities and tourists alike, it also threatens to extinguish some local firefly populations unless adequate protections are put in place.

"With this review of the current state of firefly tourism and the declining health of their habitats, we are putting out a call to action to engage local communities and governments, as well as the tourists themselves, to act as guardians of the fireflies," said lead author Sara Lewis, professor of biology at Tufts University and co-chair of the International Union for the Conservation of Nature's (IUCN) Firefly Specialist Group, which conducted the review. The IUCN firefly group works to identify key threats and conservation issues facing fireflies in different geographic regions, and advocates for the most threatened species at national and global levels. Lewis' earlier work on fireflies with the IUCN has drawn considerable attention and fascination among the public and other researchers, with media coverage including CNN and The Washington Post.

In recent years, the number of tourists has skyrocketed at several sites in Mexico, India, Taiwan, Malaysia, Thailand, and the United States. "In Mexico, the rapid growth of firefly tourism over the past decade is thrilling but also alarming," said Tania López-Palafox, graduate student at Universidad Nacional Autónoma de México and co-author of the review. "The COVID pandemic gave them a momentary respite, but we have witnessed the harm that too much tourism can do."

Aimed at site managers, tour guides, and tourists, the report highlights the need to recognize ecological requirements across all firefly life stages. To promote the breeding success of firefly adults, sites should minimize light pollution: bright lights from buildings, vehicles, flashlights, and even cell phones - all of which can disrupt firefly courtship rituals.

CAPTION

Females of many firefly species lack functional wings, making them especially vulnerable to accidental trampling in areas of heavy foot traffic.

CREDIT

Radim Schreiber

Protection of nearby habitats also plays an essential role. Fireflies spend most of their life cycle in a juvenile, larval stage. These juveniles require several months or even years to develop into their adult form and, depending on the species, spend this time living below ground, in leaf litter or sometimes underwater. The authors describe former firefly sites along mangrove rivers where commercial development and excessive motorboat traffic have degraded riverbank habitat that had been essential for supporting firefly larvae.

At some sites, the reproductive cycle of firefly populations is threatened by tourists inadvertently trampling female fireflies and degrading larval habitats. Females in many species can't fly, and so are particularly susceptible to tourist foot traffic. Learn more about the mating rituals of fireflies studied by the Tufts research team in this video.

The report noted the popularity of displays created by several kinds of synchronous fireflies found in Southeast Asia and North America, where hundreds or thousands of firefly males captivate females - and tourists, too - by flashing their lights together in unison. According to co-author Anchana Thancharoen, lecturer at Kasetsart University in Bangkok, "With such mesmerizing lights, the firefly display trees make tourists fall in love at first sight. Our aim with this call to action is to channel that love into support for conservation efforts."

###

Other recommendations by the authors include:

1) Tailored conservation practices to protect the habitats for all life stages to thrive
2) Involvement of local communities as ecological and economic stakeholders
3) Training programs for guides
4) Educational materials for visitors and best practices for transforming tourist behavior

Whether managed by local governments or run by commercial enterprises, well-managed tourism should educate global visitors to become allies in protecting firefly populations.

"There is also a larger opportunity here," said Lewis. "Fireflies hold a special fascination for people, and their fading lights make an obvious and visible case for conservation. But fireflies can also be a gateway bug to get tourists interested in conserving many other insects, which might not be so charismatic, yet still are essential building blocks for healthy ecosystems."

CAPTION

At Nanacamilpa in Mexico, tourists follow guides into the forest to view courtship displays of synchronous roving fireflies Photinus palaciosi

CREDIT

Tania López-Palafox

Climate change influences river flow

ETH ZURICH

Research News

 

Climate change is affecting the water balance of our planet: depending on the region and the time of year, this can influence the amount of water in rivers potentially resulting in more flooding or drought. River flow is an important indicator of water resources available to humans and the environment. The amount of available water also depends on further factors, such as direct interventions in the water cycle or land use change: if, for example, water is diverted for irrigation or regulated via reservoirs, or forests are cleared and monocultures grown in their place, this can have an impact on river flow.

However, how river flow has changed worldwide in recent years was so far not investigated using direct observations. Similarly, the question whether globally visible changes are attributable to climate change or to water and land management had not been clarified.

Now, an international research team led by ETH Zurich has succeeded in breaking down the influence of these factors, after analysing data from 7,250 measuring stations worldwide. The study, which has been published in the renowned scientific journal Science, demonstrates that river flow changed systematically between 1971 and 2010. Complex patterns were revealed - some regions such as the Mediterranean and north-eastern Brazil had become drier, while elsewhere the volume of water had increased, such as in Scandinavia.

The quest for the causes

"The actual question, however, concerned the cause of this change," says Lukas Gudmundsson, lead author of the study and senior assistant in the group led by Sonia Seneviratne, professor at the Institute for Atmospheric and Climate Science at ETH Zurich.

To answer this question, the researchers carried out several computer simulations, using global hydrological models fed with observed climate data from the period studied (1971 to 2010). The results of the model calculations closely matched the analysis of observed river flow. "This means that climatic conditions can explain the observed trends in the flow volumes," says Gudmundsson. In a second procedure, the researchers included additional water and land management in their simulations in order to study the influence of these factors. This did not affect the result, however. "Changes in water and land management are evidently not the cause of global changes in rivers," he says.

Although water management and land use can result in large local fluctuations in flow volumes, investigating this was not within the scope of the study, adds Gudmundsson: "For us, it was not about local trends but global changes that become visible over longer periods." This is why the researchers did not consider data from individual measuring stations in isolation, but collated them into larger subcontinental regions for the analysis, thereby making it possible to identify the influence of climate change.

The impact of greenhouse gases

The researchers were able to substantiate the role of climate change using the detection and attribution method. For this they compared the observations with simulations from climate models that were calculated once with man-made greenhouse gases and once without. In the first case the simulation matched the actual data, but in the second case it did not. "This suggests that the observed changes are highly unlikely without climate change," says Gudmundsson.

The study is the first to use direct observations to demonstrate that climate change has a globally visible influence on rivers. "This was only possible thanks to the great collaboration between researchers and institutions from 12 countries," emphasises Gudmundsson. The data collection from the 7,250 measuring stations worldwide was also the result of a joint effort: researchers had collated the data with Australian collaboration partners in a previous study. This data now represents the largest global data set with river flow observations available today. "Thanks to this data, we were able to validate the models and demonstrate that they provide a good reflection of reality," says Gudmundsson.

This means that the models can also provide reliable scenarios on how rivers will continue to change in future. Such projections provide an important basis for planning in the affected regions in order to secure water supply and adjust to climate change.

###

Has climate change altered river flows at a global scale?

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

Research News

 

The pervasive fingerprint of anthropogenic climate change is apparent in river flow at a global scale, according to a new study. While anthropogenic climate change has had quantifiable and profound effects on various Earth systems, including the global water cycle, evidence for its role in the observed changes in river flow and hydrological extremes recorded worldwide remains uncertain. Lukas Gudmundsson and colleagues analyzed thousands of time series of low, mean and high river flows from 7,250 observatories worldwide from 1971 to 2010. According to Gudmundsson et al., the historical observations revealed recent, spatially complex global hydrological trends - while rivers in some regions are drying up and flowing less, others are growing wetter, with more water coursing between their banks. Using a climate change detection and attribution approach, the authors compared the observational data to Earth system model simulations of the terrestrial water cycle. According to the results, patterns in global river flow are only consistent with model predictions that consider the effects of radiative forcing from anthropogenic climate change. The simulated effects of water and land management alone are not enough to explain the recent patterns. The findings suggest that climate change is the causal driver influencing the magnitude of river flows globally. In a Perspective, Julia Hall and Rui Perdigão argue that, while Gudmundsson et al.'s attribution to climate change is logical and likely in terms of process understanding of climate dynamics, the evidence they provide is "circumstantial;" other processes not captured by the models could contribute to the observed trends. "To improve the explanatory power of such important studies and to generate more confidence in such attribution statements, we need to move beyond these first-order assessments that involve simple proof of consistency and inconsistency when investigating the effects of climate change," Hall and Perdigão write.

For reporters interested in trends, a February 2021 Science study reported that 53% of the world's river basins have undergone marked changes in biodiversity, largely due to human activity. https://science.sciencemag.org/cgi/doi/10.1126/science.abd3369

Paleontology: Microscope helps with dinosaur puzzle

Comparison of fossil bone tissue allows more reliable assignment to individuals

UNIVERSITY OF BONN

Research News

 

IMAGE: (HERE A TEAM FROM THE AATHAL DINOSAUR MUSEUM IN WYOMING, CO-AUTHOR HANS-JAKOB SIBER FRONT CENTER) OFTEN BELONG TO DIFFERENT ANIMALS. view more 

CREDIT: (C) SAURIERMUSEUM AATHAL

Fossil sites sometimes resemble a living room table on which half a dozen different jigsaw puzzles have been dumped: It is often difficult to say which bone belongs to which animal. Together with colleagues from Switzerland, researchers from the University of Bonn have now presented a method that allows a more certain answer to this question. Their results are published in the journal Palaeontologia Electronica.

Fossilized dinosaur bones are relatively rare. But if any are found, it is often in large quantities. "Many sites contain the remains of dozens of animals," explains Prof. Dr. Martin Sander from the Institute of Geosciences at the University of Bonn.

If the finder is lucky, the bones are still arranged exactly as in the living dinosaur. Some are even still connected to each other at their joints. All too often, however, they were pulled apart and dispersed by scavengers and flowing water before being embedded in the soil. "Assigning this pile of hundreds of fossilized bones to the respective individuals from which they originally came is then usually very difficult," stresses Sander, who is also a member of the transdisciplinary research area "Building Blocks of Matter and Fundamental Interactions".

This is because, for one thing, "long bones" from the arms and legs, like the thigh bone, look remarkably similar even in different species. This means that even experts are often unable to say whether a fossil thigh bone is from Diplodocus or Brachiosaurus. And even if this could be ascertained, perhaps the excavation produced several Diplodocus specimens to which it could belong.

Sander and his doctoral student Kayleigh Wiersma-Weyand have now been able to demonstrate how this can be achieved. They used dinosaur bones from the U.S. state of Wyoming as a test object. These had been excavated and partially combined into skeletons by a team from the Aathal dinosaur museum in Switzerland shortly before the turn of the millennium.

CAPTION

the upper arm bone of a Diplodocus. The drill hole created during the removal of the fossil bone tissue sample is clearly visible.

CREDIT

(c) Martin Sander/Uni Bonn

Drilling into 150 million year old bones

The Swiss researchers made their finds available to the paleontologists in Bonn for the study. Wiersma-Weyand and Sander drilled into the 150-million-year-old bones and examined the extracted core under the microscope. "This allows us to find out how old the animal in question was when it died," Wiersma-Weyand explains. For one thing, young bones are better vascularized than old ones; this means that after fossilization they have more cavities in which the blood vessels used to be. Second, bone growth proceeds in spurts. "We therefore often see characteristic annual rings, similar to what we see in trees," the researcher says.

Estimating the age often makes it possible to rule out that a bone belongs to a particular skeleton. "If the left thigh bone is ten years older than the right one, we have a problem," Sander says laconically. There were no such discrepancies in the finds examined for the study. "However, we came across bones that had previously been attributed to two different animals, but probably belong to one and the same skeleton."

The study addresses a problem that has begun to come into scientific focus in recent years: With many mounted dinosaur skeletons located in museums and collections around the world, it is still not clear whether their bones come from one or more individuals. This combination is often done deliberately during mounting, since dinosaur skeletons are rarely preserved in their entirety. Supplementing missing bones with finds from other specimens is therefore common practice and, in principle, not a big deal as long as it is recorded. More critical, however, is when researchers combine finds unknowingly and these then come from different species or animals of different ages.

When the original Diplodocus has legs that are too short

This becomes particularly relevant when the skeletons are so-called type specimens. This is because these are considered the "standard" for the corresponding species, similar to the prototype meter. But what if, for example, the original Diplodocus contains the lower legs of a younger (and thus smaller) Diplodocus specimen? "Then some of the conclusions we draw about its locomotion and lifestyle may be wrong," Sander points out. "Our research therefore also helps combat the much-cited replication crisis in science."

Together with Kayleigh Wiersma-Weyand and Master student Nico Roccazzella, he will soon be using this method to take a closer look at a famous exhibit: the "Arapahoe" skeleton, the longest skeleton of a dinosaur in Europe, which is currently on display at the Museum Koenig in Bonn.

###

Publication: Kayleigh Wiersma-Weyand, Aurore Canoville, Hans-Jakob Siber and Martin P. Sander: Testing hypothesis of skeletal unity using bone histology: The case of the sauropod remains from the Howe-Stephens and Howe Scott quarries (Morrison Formation, Wyoming, USA); Palaeontologia Electronica; DOI: https://doi.org/10.26879/766

CAPTION

and his colleague Kayleigh Wiersma-Weyand (below) plan to examine this dinosaur skeleton currently on display at the Museum Koenig, Bonn.

CREDIT

(c) ZFMK

How does a crustacean become a crab?

Researchers find five independent carcinizations in both true and false crabs and at least seven instances of decarcinization

HARVARD UNIVERSITY, DEPARTMENT OF ORGANISMIC AND EVOLUTIONARY BIOLOGY

Research News

 

IMAGE: PHYLOGENETIC EVIDENCE FROM THE AUTHORS' PREVIOUS WORK DEMONSTRATES THAT CARCINIZED BODY PLANS HAVE EVOLVED MULTIPLE TIMES (INDICATED BY THE COLORED CHARACTERISTICS ON BRANCHES). CARCINIZED CLADES ARE: SPONGE CRABS, "HIGHER " TRUE... view more 

CREDIT: COURTESY OF JOANNA M. WOLFE.

Crabs are living the meme life on social media lately. The memes joke that everything will eventually look like a crab. But it's actually based in some truth.

The crab shape has evolved so many times the evolutionary biologist L.A. Borradaile coined the term carcinization in 1916 to describe the convergent evolution process in which a crustacean evolves into a crab-like form from a non-crab-like form. Crabs are decapod crustaceans of the infraorder Brachyura and are considered "true crabs", most of which are carcinized. "False crabs" are of the infraorder Anomura. This group evolved crab-like body plans three or more times from an ancestor that was not carcinized.

In a paper published on March 12 in BioEssays, a team of researchers led by Harvard University found that the crab-like body plan evolved at least five times independently in both true crabs (Brachyura) and false crabs (Anomura). They also discovered the crab-like body plan has been lost at least seven times in a process called decarcinization.

The team, led by first author Joanna M. Wolfe, Postdoctoral Researcher, Department of Organismic and Evolutionary Biology (OEB), Harvard University, examined a composite of phylogenetic data for crabs. They synthesized morphological data from key fossil and living crab groups as well as data from behavior, natural history, functional morphology, and development all from previous studies by the authors.

Construction of comprehensive datasets, including fossil and extant species, representing all crab families is crucial to identifying the key characters that define what is a crab," said Wolfe. "This will allow us to resolve the multiple origins and losses of 'crab' body forms through time and identify the timing of origin of key evolutionary novelties and body plans."

Carcinization is characterized by a wide, flat carapace (the hard upper shell) and a folded pleon (the abdomen or tail). The pleon is largely hidden under the crab body, unlike the pleon of the lobster which is visible. In decarcinization the carapace is elongated and narrow. The pleon is not bent and is usually visible or even elongated. Decarcinization is an example of a group re-evolving a morphology that had been lost, which is thought to be a rare event in evolution.

"Biologists want to know how to "predict" if a phenotype, or morphology, would evolve in a group," said senior author Heather D. Bracken-Grissom, Associate Professor, Florida International University. "Examining crab evolution provides a macroevolutionary timescale of 250 million years ago for which, with enough phylogenetic and genomic data, we might be able to predict the morphology that would result."

Wolfe agreed, "Carcinization also allows us to compare convergent evolution in fossil morphology to that in living organisms, which is not yet commonly done."

The researchers are not completely certain but posit it is likely the common ancestor of Brachyura and Anomura was not carcinized. "This evidence suggests that indeed carcinization evolved independently in those groups," said co-author Javier Luque, Postdoctoral Researcher, OEB, Harvard University and Smithsonian Tropical Research Institute.

Wolfe is currently working with Assistant Professor Javier Ortega-Hernández, OEB, Harvard University, to test the hypothesis that carcinization can be quantitatively characterized by measuring the shapes of extant crab specimens from the Museum of Comparative Zoology, Harvard University, collections.

###

This work was supported by the National Science Foundation DEB #1856679, DEB #1856667, and a National Sciences and Engineering Research Council of Canada (NSERC) Post- doctoral Fellowship.

Article and author details

Joanna M. Wolfe, Javier Luque, Heather D. Bracken-Grissom. 2021. How to become a crab: Phenotypic constraints on a recurring body plan. BioEssays DOI: 10.1002/bies.202100020

Corresponding author(s)

Joanna Wolfe, jowolfe@g.harvard.edu

 

#ENDWOLFHUNTING

Weakened protections led to more disappearances of endangered Mexican wolves

UNIVERSITY OF WISCONSIN-MADISON

Research News

 

MADISON, Wis. -- Mexican wolves in the American Southwest disappeared more quickly during periods of relaxed legal protections, almost certainly succumbing to poaching, according to new research published Wednesday.

Scientists from the University of Wisconsin-Madison found that Mexican wolves were 121% more likely to disappear -- despite high levels of monitoring through radio collars -- when legal rulings permitted easier lethal and non-lethal removal of the protected wolves between 1998 and 2016. The disappearances were not due to legal removal, the researchers say, but instead were likely caused by poachers hiding evidence of their activities.

The findings suggest that consistently strong protections for endangered predators lead to reduced poaching, contrary to theories that legalizing lethal removal might reduce the motivation to poach. Instead, the scientists say, strong protections could signal both the value of endangered predators and the government's intent to enforce protections. However, exactly how government policies ultimately influence poaching activity remains unclear.

"Top predators are very important to healthy ecosystems," says Adrian Treves, a UW-Madison professor of environmental studies who oversaw the new research. "They are imperiled globally by human activities. And among human-caused mortality, poaching is the leading cause."

Treves, graduate student Naomi Louchouarn and postdoctoral researcher Francisco Santiago-Ávila published their findings March 10 in the Royal Society Open Science journal. They collaborated with David Parsons, a former U.S. Fish and Wildlife Service agent and a member the Project Coyote science advisory board, to perform the analysis.

The new report comes on the heels of the federal government's delisting of the grey wolf in November 2020 under the Endangered Species Act, which reduced protections for the carnivores.

The Mexican wolf population, a subspecies of the grey wolf, is an ideal candidate for studying the effect of government policies. Thanks to intensive reintroduction efforts, more than half of the wolves are monitored through tracking collars, which provide high-quality data on the fate of individual wolves. Policies changed multiple times over roughly two decades, creating a natural experiment that researchers can use to observe how more relaxed or stringent protections affected wolf populations.

The Treves lab asked how two distinct changes in federal protections for Mexican wolves affected the mortality of the predators in the ensuing years. From 2005 to 2009, and again from 2015 until the end of the study period in 2016, federal regulators relaxed protections for the wolves. These new policies allowed agencies to more readily remove by lethal means wolves that were deemed threats to people or livestock. Public hunting was never legalized.

The researchers found that the only cause of lost wolves that changed significantly during times of reduced protections was a category known as lost-to-follow-up, or LTF. The LTF category includes all wolves that can no longer be accounted for. LTFs can be caused by radio collar battery failures, or by wolves migrating beyond the monitored area.

Yet, the U.S. Fish and Wildlife Service found few, if any, migrants out of the recovery area and LTF events occurred significantly earlier than the expected battery life of radio collars. Those results mean that these two common causes of LTF status likely can't account for the large increase in wolves lost-to-follow-up during years of relaxed protections. The Treves group also found no evidence of changes in diseases or climate that correlated with policy changes and would increase disappearances.

Instead, they believe that the increased risk of disappearance comes from poachers who act to hide their activities by destroying radio collars and hiding carcasses. Without that evidence, however, federal agencies can't confirm a cause of death, forcing them to declare the wolves lost-to-follow-up.

Agency removal of wolves and confirmed poaching activities did not vary significantly based on policy period.

"The fact that these changes line up with these periods really tells you a lot. The wolves don't understand that policy changed, but people do," says Louchouarn. "Yet the disappearances did increase, so somebody was changing their behavior. These methods really helped us to make that connection to likely poaching."

To reduce sources of bias, the researchers developed their methods and submitted them to peer review before completing their analysis. This pre-review encourages more transparent publishing of scientific findings, regardless of the final results.

"Our findings suggest that there is no evidence for the tolerance killing hypothesis, where allowing the killing of more individuals is going to increase the tolerance for the species and therefore reduce killings," says Santiago-Ávila, who originally developed the data analysis methods to study Wisconsin's wolf population. "There is a very minimal reduction in the poaching that gets reported. But that's only because the poaching gets translated to lost individuals, which we believe represents underreported poaching."

The researchers say government agencies should reassess their assumptions that lethal removal can ultimately lead to better outcomes for the wolves. Federal policies are developed based on scientific research, so reports like this one and a previous study of Wisconsin's wolf population could help federal agencies reevaluate for the future.

"Protection is the thing that's reducing poaching," says Treves.

###

NICOLA TESLA'S DREAM

Contactless high performance power transmission

Superconducting coils for contactless power transmission in the kilowatt range

TECHNICAL UNIVERSITY OF MUNICH (TUM)

Research News

 

IMAGE: A TEAM OF PHYSICISTS AT THE TECHNICAL UNIVERSITY OF MUNICH HAS DEVELOPED A COIL MADE OF SUPERCONDUCTING WIRES THAT CAN TRANSMIT POWER OF MORE THAN FIVE KILOWATTS CONTACTLESS WITHOUT MAJOR... view more 

CREDIT: CHRISTOPH UTSCHICK / WUERTH ELEKTRONIK EISOS

A team led by Christoph Utschick and Prof. Rudolf Gross, physicists at the Technical University of Munich (TUM), has developed a coil with superconducting wires capable of transmitting power in the range of more than five kilowatts contactless and with only small losses. The wide field of conceivable applications include autonomous industrial robots, medical equipment, vehicles and even aircraft.

Contactless power transmission has already established itself as a key technology when it comes to charging small devices such as mobile telephones and electric toothbrushes. Users would also like to see contactless charging made available for larger electric machines such as industrial robots, medical equipment and electric vehicles.

Such devices could be placed on a charging station whenever they are not in use. This would make it possible to effectively utilize even short idle times to recharge their batteries. However, the currently available transmission systems for high performance recharging in the kilowatt range and above are large and heavy, since they are based on copper coils.

Working in a research partnership with the companies Würth Elektronik eiSos and superconductor coating specialist Theva Dünnschichttechnik, a team of physicists led by Christoph Utschick and Rudolf Gross have succeeded in creating a coil with superconducting wires capable of contactless power transmission in the order of more than five kilowatts (kW) and without significant loss.

Reduced alternating current loss in superconductors

This meant the researchers had to overcome a challenge. Minor alternating current losses also occur in superconducting transmission coils. These losses grow as transmission performance increases, with a decisive impact: The surface temperature of the superconducting wires rises and the superconduction collapses.

The researchers developed a special coil design in which the individual windings of the coil are separated from one another by spacers. "This trick significantly reduces alternating current loss in the coil," says Christoph Utschick. "As a result, power transmission as high as the kilowatt range is possible."

Optimization with analytical and numerical simulations

The team chose a coil diameter for their prototype that resulted in a higher power density than is possible in commercially available systems. "The basic idea with superconducting coils is to achieve the lowest possible alternating current resistance within the smallest possible winding space and thus to compensate for the reduced geometric coupling," says Utschick.

This called on the researchers to resolve a fundamental conflict. If they made the distance between the windings of the superconducting coil small, the coil would be very compact, but there would be a danger of superconduction collapse during operation. Larger separations would on the other hand result in lower power density.

"We optimized the distance between the individual windings using analytical and numerical simulations," says Utschick. "The separation is approximately equal to half the width of the tape conductor." The researchers now want to work on further increasing the amount of transmittable power.

Exciting application areas

If they succeed, the door will open to a large number of very interesting application areas, for example uses in industrial robotics, autonomous transport vehicles and high-tech medical equipment. Utschick even envisions electric racing vehicles which can be charged dynamically while on the race track, as well as autonomous electric aircraft.

Wide-scale applicability of the system still faces an obstacle, however. The coils require constant cooling with liquid nitrogen, and the cooling vessels used cannot be made of metal. The walls of metal vessels would otherwise heat up considerably in the magnetic field, much as a pot does on an induction stove.

"There is as yet no cryostat like this which is commercially available. This will mean an extensive amount of further development effort," says Rudolf Gross, Professor for Technical Physics at the Technical University of Munich and Director of the Walther-Meissner-Institute of the Bavarian Academy of Sciences and Humanities. "But the achievements up to now represent major progress for contactless power transmission at high power levels."

###

Cooperation partner Würth Elektronik eiSos defined the topic and financed the industrial promotion underlying this publication. Essential parts of the research were conducted at the Walther-Meissner-Institute (WMI) of the Bavarian Academy of Sciences and Humanities. The high-temperature superconductors used were provided by Theva Dünnschichttechnik, a spin-off company of the Technical University of Munich.

Publication:

Christoph Utschick, Cem Som, Ján Souc, Veit Große, Fedor Gömöry and Rudolf Gross
Superconducting Wireless Power Transfer Beyond 5 kW at High Power Density for Industrial Applications and Fast Battery Charging.
IEEE Transactions on Applied Superconductivity, 2. Februar 2021 - DOI: 10.1109/TASC.2021.3056195

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

    SHARE

 PRINT

 

Air pollution: The silent killer called PM2.5

Over half the world's population lives without the protection of proper air quality standards

MCGILL UNIVERSITY

Research News

 

Millions of people die prematurely every year from diseases and cancer caused by air pollution. The first line of defence against this carnage is ambient air quality standards. Yet, according to researchers from McGill University, over half of the world's population lives without the protection of adequate air quality standards.

Air pollution varies greatly in different parts of the world. But what about the primary weapons against it? To find answers, researchers from McGill University set out to investigate global air quality standards in a study published in the Bulletin of the World Health Organization.

The researchers focused on air pollution called PM2.5 - responsible for an estimated 4.2 million premature deaths every year globally. This includes over a million deaths in China, over half a million in India, almost 200,000 in Europe, and over 50,000 in the United States.

"In Canada, about 5,900 people die every year from air pollution, according to estimates from Health Canada. Air pollution kills almost as many Canadians every three years as COVID-19 killed to date," says co-author Parisa Ariya, a Professor in the Department of Chemistry at McGill University.

Small but deadly

Among the different types of air pollution, PM2.5 kills the most people worldwide. It consists of particles smaller than approximately 2.5 microns - so small that billions of them can fit inside a red blood cell.

"We adopted unprecedented measures to protect people from COVID-19, yet we don't do enough to avoid the millions of preventable deaths caused by air pollution every year," says Yevgen Nazarenko, a Research Associate at McGill University who conducted the study with Devendra Pal under the supervision of Professor Ariya.

The researchers found that where there is protection, standards are often much worse than what the World Health Organization considers safe. Many regions with the most air pollution don't even measure PM2.5 air pollution, like the Middle East. They also found that the weakest air quality standards are often violated, particularly in countries like China and India. In contrast, the strictest standards are often met, in places like Canada and Australia.

Surprisingly, the researchers discovered that high population density is not necessarily a barrier to fighting air pollution successfully. Several jurisdictions with densely populated areas were successful in setting and enforcing strict standards. These included Japan, Taiwan, Singapore, El Salvador, Trinidad and Tobago, and the Dominican Republic.

"Our findings show that more than half of the world urgently needs protection in the form of adequate PM2.5 ambient air quality standards. Putting these standards in place everywhere will save countless lives. And where standards are already in place, they should be harmonized globally," says Nazarenko.

"Even in developed countries, we must work harder to clean up our air to save hundreds of thousands of lives every year," he says.

###

About this study

"Air quality standards for the concentration of particulate matter 2.5, global descriptive analysis" by Yevgen Nazarenko, Devendra Pal, and Parisa Ariya was published in the Bulletin of the World Health Organization.

DOI: http://dx.doi.org/10.2471/BLT.19.245704

About McGill University

Founded in Montreal, Quebec, in 1821, McGill University is Canada's top ranked medical doctoral university. McGill is consistently ranked as one of the top universities, both nationally and internationally. It?is a world-renowned?institution of higher learning with research activities spanning two campuses, 11 faculties, 13 professional schools, 300 programs of study and over 40,000 students, including more than 10,200 graduate students. McGill attracts students from over 150 countries around the world, its 12,800 international students making up 31% of the student body. Over half of McGill students claim a first language other than English, including approximately 19% of our students who say French is their mother tongue.

https://www.mcgill.ca/newsroom/