It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, October 26, 2021
Tattoo inks: Minimum requirements and test methods
Opinion No 031/2021 of the German Federal Institute for Risk Assessment (BfR) of 14 October 2021
Tattoo inks contain pigments and additives. According to the provisions of the German Food, Consumer Goods and Feed Code (Lebensmittel-, Bedarfsgegenstände- und Futtermittelgesetzbuch, LFGB), tattoo inks may not be used if there is any doubt as to their safety to health. Substances or mixtures for tattooing purposes are regulated in the REACH Regulation [entry 75 of Annex XVII of the REACH Regulation (Regulation (EC) No 1907/2006)]. However, there are as yet no binding criteria according to which a safety assessment of tat-too inks should be carried out. There is also a lack of suitable test methods and data for a health risk assessment. For example, little is known about adverse effects that may be associated with the injection of tattoo inks into the skin or about possible effects that may be induced in other organs. Therefore, the German Federal Institute for Risk Assessment (BfR) has developed minimum requirements for tattoo inks as well as test methods for manufacturers and distributors who are primarily responsible for the safety of their products.
Test methods are already available for the minimum toxicological and analytical requirements presented, so that they can be applied immediately. In addition, the BfR indicates requirements for which further research is necessary or methods would have to be developed, i.e., which are therefore not yet operable at present. The BfR minimum requirements presented below are intended to mark the basis for a future health risk assessment of tattoo inks and the start of a comprehensive consultation process with all stakeholders from science, industry, politics and the public. As pigments form the main component of tattoo inks, they are particularly important for the health risk assessment for the protection of consumers. Therefore, the BfR has particularly considered pigments in this statement. The Institute expects that already by applying the operable minimum require-ments described here, the level of protection of tattooed persons can be significantly increased compared to the current situation. On the one hand, the minimum requirements are intended to help identify tattoo pigments that are not suitable for tattoos. On the other hand, the use of pigments that meet the minimum toxicological requirements will reduce potential health risks according to the current state of science and technology. However, due to a lack of data, the BfR does not currently make any recommendations for use.
The German Federal Institute for Risk Assessment (BfR) is a scientifically independent institution within the portfolio of the Federal Ministry of Food and Agriculture (BMEL) in Germany. The BfR advises the Federal Government and the States (‘Laender’) on questions of food, chemical and product safety. The BfR conducts its own research on topics that are closely linked to its assessment tasks.
IMAGE: SOME OF THE RECORDED CARNIVORE SPECIES FROM UPPER LEFT TO LOWER RIGHT: SUN BEAR, MARBLED CAT, FLAT-HEADED CAT, SMOOTH OTTERS, YELLOW-THROATED MARTEN, BANDED LINSANG, BINTURONG, COMMON PALM CIVET, MALAY CIVETview more
CREDIT: MIYABI NAKABAYASHI (HIROSHIMA UNIVERSITY), TOMOKO KANAMORI (PRIMATE RESEARCH INSTITUTE, KYOTO UNIVERSITY), AOI MATSUKAWA (WILDLIFE RESEARCH CENTER, KYOTO UNIVERSITY), IKKI MATSUDA (CHUBU UNIVERSITY ACADEMY OF EMERGING SCIENCES), GORO HANYA (PRIMATE RESEARCH INSTITUTE, KYOTO UNIVERSITY)
Just as humans may leave their home five minutes early to avoid a talkative neighbor or depart work late to avoid a rude coworker, carnivorous mammals may go out of their way to avoid other species. But they’re not trying to navigate awkward social interactions; rather, they are negotiating space and resources for survival.
Researchers monitored this temporal niche partitioning intermittently over six years with 73 infrared trigger sensor cameras installed at three sites in the Malaysian state of Sabah on Borneo, the third largest island in the world. The international collaboration published their findings, and what they might mean for the mechanism of coexistence between competing mammals, on Oct. 6 in Scientific Reports.
“Approximately 20% of the world’s mammal species face the risk of extinction, mainly due to threats such as habitat loss and overexploitation,” said first author Miyabi Nakabayashi, assistant professor in the Graduate School of Advanced Science and Engineering at Hiroshima University. “The status of mammals in the Indomalayan realm — one of Earth’s eight biogeographic regions, covering most of South and Southeast Asia — is among the world’s worst.”
One of the major roadblocks to effective and realistic solutions to lower the rate of endangered species is the scarcity of basic ecological information on mammals in the Indomalayan region, according to Nakabayashi.
“Information regarding temporal activity patterns of animals is crucial to assess responses to anthropogenic disturbances and to allow the implementation of proper conservation measures,” Nakabayashi said. “Camera trapping is one of the most useful techniques to study cryptic and rare animals.”
The researchers collected 37,379 photos over a total of about three active years. Although the first cameras were installed in 2010 and the last ones were removed in 2016, there were significant periods of bad weather or logistical issues — such as nesting insects — that rendered the cameras inoperable for long stretches of time.
In the dataset, the researchers identified nine distinct carnivore species with sample sizes larger than 10 and categorized their activity patterns by time of day. Of the species, six were active at night, two were active during the day and one was active regardless of time.
Some of the more closely related animals demonstrated a clear temporal segregation, including two wild cats, one of whom was nocturnal while the other preferred the day. However, the researchers also found that three species of civets were all active at night, which might be due to limited competition over resources because all three species eat a variety of food items, Nakabayashi said.
The researchers also found that tourism may have an impact on mammal behaviors. Tourism activities — mainly non-lethal ecotourism events — were conducted at all study sites during the study period. Only one site, however, hosted nocturnal tourism activities. Common palm civets at the other two sites had two clear peaks of temporal activity at night, but the same species at the site with nocturnal tourism had unclear and delayed temporal movement.
“The potential benefits of ecotourism may include reduced threats to wildlife ,” Nakabayashi said, noting that community-based ecotourism can bring significant benefits such as alternative income that incentivizes local communities and policy makers to protect the species in areas of interest. “But our results indicate that the temporal activity pattern of a species might be directly affected by tourism activity. The effect of tourism on animal behavior should be evaluated, even though it is non-lethal ecotourism.”
The researchers also recommended a two- to three-year-long study with at least 10 cameras to gather more data on the activities of the carnivores.
“Current information is too limited and sporadic to understand basic behaviors of mammals, which may affect the progress in evaluating and improving the threatened status,” Nakabayashi said. “We should accumulate more information on rare species to determine their basic ecology and to reassess whether current conservation management strategies are appropriate.”
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Other contributors include Tomoko Kanamori and Goro Hanya, Primate Research Institute at Kyoto University; Aoi Matsukawa, Wildlife Research Center, Kyoto University; Joseph Tangah, Forest Research Centre, Sabah Forestry Department in Malaysia; Augustine Tuuga and Titol Peter Malim (deceased), Sabah Wildlife Department in Malaysia; Henry Bernard, Primate Studies-Borneo, Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah; Abdul Hamid Ahmad, Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah; and Ikki Matsuda, the Chubu University Academy of Engineering Sciences in Japan
Kanamori is also affiliated with the Japan Orangutan Research Center. Matsuda is also affiliated with the Primate Studies-Borneo, Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, the Wildlife Research Center at Kyoto University and the Japan Monkey Centre.
The Japan Society for the Promotion of Science (22687002, 26711027, 19H03308, 17K15285, 20K15555, JPJSCCA20170005, 25-597 and 201608680) and the Sasagawa Scientific Research Grant from the Japan Science Society (22-537) partially supported this research.
About Hiroshima University
Since its foundation in 1949, Hiroshima University has striven to become one of the most prominent and comprehensive universities in Japan for the promotion and development of scholarship and education. Consisting of 12 schools for undergraduate level and 4 graduate schools, ranging from natural sciences to humanities and social sciences, the university has grown into one of the most distinguished comprehensive research universities in Japan. English website: https://www.hiroshima-u.ac.jp/en
Temporal activity patterns suggesting niche partitioning of sympatric carnivores in Borneo, Malaysia
ARTICLE PUBLICATION DATE
6-Oct-2021
Major step in UK contribution to space mission to study solar wind
Space scientists from the University of Leicester have delivered a key component for a new mission to study the impact of the solar wind on Earth’s magnetic field.
IMAGE: (L-R) CHRIS BICKNELL, CHARLOTTE BOULDIN AND ANDY CHENEY OF THE UNIVERSITY OF LEICESTER COMPLETING FINAL WORK ON THE SXI STRUCTURAL AND THERMAL MODEL PRIOR TO DELIVERY TO AIRBUS, SPAIN.view more
CREDIT: UNIVERSITY OF LEICESTER
Space scientists from the University of Leicester have delivered a key component for a new mission to study the impact of the solar wind on Earth’s magnetic field.
Engineers from the University’s Space Research Centre have completed the structural and thermal model for the UK’s latest X-ray telescope, the Soft X-ray Imager (SXI), destined for space aboard the SMILE (Solar wind Magnetosphere Ionosphere Link Explorer) probe when it launches at the end of 2024.
The model, which has now been delivered to Airbus in Spain for integration and testing within the prototype satellite system, is not the so-called flight model – but will help engineers understand the extreme requirements for the final design.
Specialists will subject the prototype to the significant vibrations, shocks and G-forces experienced during launch of the spacecraft, as well as the extreme temperatures it must operate at in space below -150oC.
Dr Steven Sembay, Principal Investigator (PI) for the SXI instrument, based at the University of Leicester, said:
“The STM testing is always a slightly nervous time, especially when you see videos of how much the instrument is shaken during testing!
“It is the first time you go from conceptual design in computer models to a real object in metal. I shouldn’t have worried. It is a testament to the skill of our engineering and manufacturing team that what is a complex piece of kit works as predicted.”
The SXI consortium is led by the University of Leicester in collaboration with UCL Mullard Space Science Laboratory (UCL MSSL), the Open University and European partners.
UCL MSSL is responsible for building the electronics that operate the SXI detectors and retrieve the signals that produce X-ray images of the space around the Earth.
The UK Space Agency has committed £10.5 million in funding for UK leadership roles on SMILE, including the SXI instrument. The compact X-ray telescope is the only European instrument planned for the mission.
SMILE is the first joint project between the European Space Agency (ESA) and the Chinese Academy of Sciences (CAS) from conceptual design to operations, and will study the continuous stream of charged particles emitted by our Sun.
Professor Graziella Branduardi-Raymont of UCL MSSL, European Co-Principal Investigator for the mission, said:
“One of the most interesting aspects of SMILE SXI is the fact that we are using technology so far applied for looking outwards to X-ray sources in the far Universe to study how our own Earth responds to the impact of the Sun’s activity.”
The highly variable stream of high energy particles, called the solar wind, impacts on the Earth’s magnetic field. At times of high intensity this stream can be a hazard to space-based instrumentation or even, in rare cases, ground-based electrical systems.
Fortunately, the Earth’s magnetic field provides protection, but this compresses and expands as it responds to variations in the highly dynamic solar wind.
CAPTION
SMILE's Soft X-ray Imager structural and thermal model arrives at Airbus, Spain.
CREDIT
Airbus
SXI will continuously monitor the position of the boundary between the region of space controlled by the Earth’s magnetic field and the solar wind. Its images will, in conjunction with the other instruments on SMILE, help scientists to refine models of how this Sun-Earth connection responds to the most infamous example of so-called ‘space weather’.
Dr Caroline Harper, Head of Space Science at the UK Space Agency, said:
“Space weather – such as the solar wind – has the potential to disrupt satellites we rely on every day for services such as global communications or managing power grids.
“This mission is a prime example of how, by working with our international partners, the UK is doing innovative science in space, while underpinning the broader economy by supporting the development of real-world applications, such as space weather modelling. It is fantastic to see the first full model of the SXI instrument being delivered and we look forward to the completion of the engineering model and eventually the flight instrument, over the next two years.”
SXI weighs around 36 kg and needed to be compact and relatively low mass to meet the mission level requirements of the spacecraft. To achieve this the telescope employs a very lightweight optical system to focus X-rays; a ‘lobster-eye’ lens which mimics the mechanism within the eye of a crustacean.
The University of Leicester’s Space Research Centre is a world leader in the development of X-ray instruments for space and SMILE’s SXI is the third instrument to use similar optics to be built at Leicester following the Mercury Imaging X-ray Spectrometer (MIXS) instrument on ESA’s BepiColombo, which has recently successfully completed its first fly-by of destination planet Mercury, and the soon-to-be-launched MXT instrument on the French-Chinese SVOM mission.
CAPTION
SMILE's Soft X-ray Imager structural and thermal model arrives at Airbus, Spain.
CREDIT
Airbus
Black hole thermodynamics: a history from Penrose to Hawking
New research explores the historical context of Penrose’s theory of black hole energy extraction, and how it inspired collaborations across political boundaries: ultimately leading to Stephen Hawking’s celebrated theory of black hole radiation.
In 1969, English physicist Roger Penrose discovered a property which would later allow for a long-awaited link between thermodynamics, and the far stranger mechanics of black holes. Through new analysis published in EPJ H, Carla Rodrigues Almeida, based at the University of São Paulo, Brazil, sheds new light on Penrose’s motivations and methods, and explores their historical influence on the groundbreaking discovery of Hawking radiation.
Prior to the 1950s, many physicists were reluctant to accept the idea that black holes are physical objects, consistent with the well-established laws of thermodynamics. This picture transformed entirely over the next two decades, and in 1969, Penrose showed for the first time how energy can be extracted from a rotating black hole. His theory hinged on a newly-conceived region named the ‘ergosphere.’
Although it lies just outside the boundary of a black hole, spacetime within the ergosphere rotates alongside the body, like the gas in a planet’s atmosphere. If a piece of matter enters the region, Penrose proposed that it may split into two parts: one of which can fall into the black hole; while the other can escape, carrying more energy than the original particle.
Over the next few years, Soviet physicist Yakov Zel’doivh explored Penrose’s discovery through the lens of quantum mechanics. Although his work was held back by political circumstances, Zel’doiv established friendly collaborations with Western physicists. Ultimately, the theories that emerged through these relationships led to Stephen Hawking’s discovery of novel quantum effects, which can cause black holes to radiate mass. Finally, the physics community was convinced that black holes can indeed obey the laws of thermodynamics.
In her study, Almeida investigates Penrose’s proposal within this historical context. By revisiting original papers, analysing technological details, and exploring relationships between Western and Soviet physicists, she aims to uncover the history they hide. The article moves through the chain of reasoning which led from Penrose’s proposal, to an analogy between thermodynamics and black hole physics; and ultimately, to the formulation of Hawking radiation.
The thermodynamics of black holes: from Penrose process to Hawking radiation
Examining the accelerating universe
A new collection of papers focuses on the paradigm of the accelerating expansion of the Universe in turn unpacking some of cosmology’s most pressing questions.
A special edition of EPJST, edited by Balasubramanian Ananthanarayan, Centre for High Energy Physics, Indian Institute of Science, Bangalore, and Subhendra Mohanty, Department of Theoretical Physics, Physical Research Laboratory, Navrangpura, Ahmedabad, brings together a collection of papers focusing improving our understanding of the accelerating expansion of the Universe and the nature of the dark energy that drives it.
“Despite all the advances in theory and observations in particle physics and cosmology we only understand about 5% of the Universe,” says Mohanty. “The remaining matter and energy of the Universe consist of dark matter, which accounts for the rotational speeds of galaxies and formation of cosmic structure, and dark energy which accelerates the expansion of the Universe.”
In addition to the lingering mysteries of the so-called ‘dark universe’ as theories have grown more robust and observations more precise, troubling disparities have presented themselves between our best descriptions of the Universe. For instance, the rate of acceleration delivered by astronomical observations and the standard model of cosmology is much smaller than the value presented by the standard model of particle physics. “If the discrepancy between different observations is not resolved even after more refined observations, then it will mean that the base model of Lambda CDM – the most favoured standard model of cosmology – needs to be changed,” Mohanty explains. “It is possible that there are interactions between different sectors like dark matter and dark energy which we have not yet recognised.”
The researcher points out that failure to resolve this disparity could also mean that the way we currently measure cosmological distance using the spectroscopic red-shift and the use of standard candles like Type-1a supernovae or Cepheid variables – stars whose luminosity varies periodically with time – needs to be revised.
Mohanty continues by explaining that there are two strands of research in this field, the first being the examination and interpretation of the observational data about what it tells us about the existence of dark energy. The second strand is the microscopic understanding of the nature of dark energy – a fluid that has negative pressure. This, as Mohanty points out, makes dark energy unlike any other particle or field observed so far.
“Unravelling the nature of dark energy by study of the accelerated Universe will unlock the deepest level of our understanding of the Universe,” Mohanty concludes. “The best way to proceed in the understanding of dark energy is to closely relate theory with observations which are now possible due to a plethora of new precision experiments in cosmology and particle physics.”
IMAGE: WSU RESEARCHER ALEXA CARR WITH HER CAT MARLEYview more
CREDIT: BOB HUBNER, WASHINGTON STATE UNIVERSITY
PULLMAN, Wash. – Pets are not the only ones who experience separation anxiety; their people do too.
Washington State University researchers surveyed a sample of new first-year college students leaving pets at home and found that 75% experienced some level of pet separation anxiety—with one in four reporting moderate to severe symptoms.
“Students who are struggling with missing their pets should know that they're not alone,” said Alexa Carr, the lead author of the study which is part of her WSU doctoral dissertation. “There’s nothing necessarily wrong with them if they are experiencing a lot of distress from leaving their pets. It can be an isolating experience to lose that coping resource.”
The students who had higher anxiety tended to be those who treated their pets more like people, identifying them as friends, sleeping in the same room and generally spending a lot of time with them. Interestingly, students who had dogs at home also tended to report more attachment to their pets—and more separation anxiety—than those with cats and other types of pets.
While there are many anecdotal accounts of students missing their pets, the study published in Anthrozoos, is the first known research investigating this kind of pet separation anxiety in humans.
Carr and co-author Patricia Pendry, a WSU associate professor of human development, surveyed a sample of about 150 incoming first-year students who had pets at home. The vast majority of respondents, 81%, were women—which is a limitation of the study but also consistent with trends in college enrollment. In 2020, 60% of enrolled college students were women, according to National Center for Education Statistics.
The researchers surveyed the group before they arrived on campus and after their first two weeks of the semester in fall 2019 before the pandemic forced many universities online. The students answered questions related to their mental health, attachment to their pets and feelings about leaving them behind.
Even after controlling for pre-existing mental health issues, the researchers found that pet-related separation anxiety was very strong in the group during the transition to college, especially among students who were closely attached to their pets.
The findings indicate this is an issue for many students and should be taken seriously by campus counselors, Carr said. It also has implications for pet visitation programs now popular at many U.S. universities which bring animals to campus to help stressed students. A previous WSU study found that petting dogs or cats for just 10 minutes lowers levels of the stress hormone cortisol.
The authors said more research is needed to understand the implications of pet separation anxiety. For example, whether students’ symptoms are stable or become less severe over the course of the semester; or whether pet visitation programs might have some unintended effects, such as potentially exacerbating separation anxiety for students missing their specific pets back home.
The researchers also cautioned that this study should not be used as justification for students to bring their pets with them when they go to college, particularly if they would be their sole caregivers.
“It’s a big responsibility to take care of an animal, and would a student then able to balance their school responsibilities, social lives and jobs?” Carr said. “There are more things to take into consideration and explore before we could advocate for more pets on campus.”
A new paper in The Economic Journal indicates that a large-scale government subsidy aimed at encouraging people to eat out in restaurants in the wake of the first 2020 COVID-19 wave in the United Kingdom accelerated a second COVID19 wave.
The COVID19 pandemic caused by the novel coronavirus hurt economies around the world. The hospitality sector was particularly vulnerable due to forced decline in tourism and leisure activities. This rippled across economies, as hospitality workers then reduce their spending and have trouble meeting basic expenses. Some governments have used fiscal policy to help the hospitality sector by stimulating demand. This paper explored to what extent an intervention in the United Kingdom, the Eat-Out-To-Help-Out scheme – had the inadvertent effect of promoting COVID19 infections.
The scheme was designed to encourage demand for hospitality and restaurant businesses. It directly subsidized the cost of meals and non-alcoholic drinks by up to 50% across participating restaurants across the UK for meals served on all Mondays to Wednesdays from August 3 to August 31, 2020. The discount was capped at a maximum of GBP 10 per person but there was no limit on how often people could benefit. Aggregate data suggest that the government subsidized 160 million meals were subsidized, costing the taxpayer £849 million. Restaurant visits increased drastically on Monday to Wednesday, which usually see less traffic. Official government statistics released at the end of January 202 suggest that at least 59,981 businesses have registered for the scheme.
Researchers here found that the program did have a notable temporary impact on restaurant visits when comparing year-on-year changes from the booking service OpenTable. During days that the scheme was available, restaurant visits increased between 10-200%. Yet, the data also suggests that the scheme may have shifted restaurant visits from the weekend to weekdays on which the discount was available and that the increased number of restaurant visits was temporary.
Areas with higher participation in the Eat-Out-To-Help-Out scheme saw both a notable increase in new COVID19 infection clusters within a week of the scheme starting, and a deceleration in infections within two weeks of the program ending. Areas that had notable rainfall during the prime lunch and dinner hours on days the scheme was active, making customers less likely to visit restaurants and take advantage of the subsidized meals, had a lower infection rate.
The empirical estimates suggest that the subsidized restaurant meal scheme may be responsible for around 11% of all new detected COVID19 clusters emerging during August and into early September in the United Kingdom.
Subsidising the spread of COVID-19: Evidence from the UK’s Eat-Out-to-Help-Out” Scheme
ARTICLE PUBLICATION DATE
26-Oct-2021
COI STATEMENT
N/A
Managing water resources in a low-to-no-snow future
With mountain snowpacks shrinking in the western US, new Berkeley Lab study analyzes when a low-to-no-snow future might arrive and implications for water management
VIDEO: A NEW BERKELEY LAB ANALYSIS FINDS THAT IF GREENHOUSE GAS EMISSIONS CONTINUE ALONG THE HIGH-EMISSIONS SCENARIO, LOW-TO-NO-SNOW WINTERS WILL BECOME A REGULAR OCCURRENCE IN THE WESTERN U.S. IN 35 TO 60 YEARS.view more
CREDIT: JENNY NUSS/BERKELEY LAB
Mountain snowpacks around the world are on the decline, and if the planet continues to warm, climate models forecast that snowpacks could shrink dramatically and possibly even disappear altogether on certain mountains, including in the western United States, at some point in the next century. A new study led by researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) analyzes the likely timing of a low-to-no-snow future, what it will mean for water management, and opportunities for investments now that could stave off catastrophic consequences.
Their review paper, “A low-to-no-snow future and its impacts on water resources in the western United States,” published in the journal Nature Reviews Earth and Environment, analyzes previous climate projections and finds that if greenhouse gas emissions continue along the high-emissions scenario, low-to-no-snow winters will become a regular occurrence in the western U.S. in 35 to 60 years. Further, the study re-evaluates longstanding assumptions in water management in the U.S. and stresses that scientists and water managers need to work together more closely to develop and implement climate adaptation strategies.
The Sierra Nevada, Rockies, Cascades, and other mountain ranges provide a tremendous service by capturing, storing, and releasing water for downstream use. Historically, snowmelt timing provides a critical delay in the delivery of water supply during the spring and into the summer, when precipitation is low and when water demands are at their highest due to agriculture. The factors causing shrinking snowpacks are predominantly tied to temperature increases and shifting precipitation characteristics. Warmer temperatures also imply that storms will produce more rainfall and less snowfall, limiting the amount of seasonal snowpack that can build through the winter.
The research, co-led by authors Erica Siirila-Woodburn and Alan Rhoades of Berkeley Lab’s Earth & Environmental Sciences Area, starts with a literature review which distills several hundred scientific studies on snow loss; of those, they identify and analyze 18 studies that had quantitative snowpack projections for the western U.S.
When will the low-to-no-snow future arrive?
“A recent study highlighted that there has been a 21% decline in the April 1 snowpack water storage in the western U.S. since the 1950s – that’s equivalent to Lake Mead’s storage capacity. In our review, we found that around mid-century we should expect a comparable decline in snowpack,” said Rhoades. “By the end of the century, the decline could reach more than 50%, but with a larger range of uncertainty.”
Many water managers use the somewhat arbitrary date of April 1 to make snowpack observations and planning decisions. Over the last several decades, there have been decreases in peak snowpack volume as well as earlier occurrences of the timing of peak snowpack, with the peak occurring approximately 8 days earlier in the year for every 1 degree Celsius (1.8 degrees Fahrenheit) of warming.
Many regions have already experienced winters with very little snow in recent years, such as the Sierras in 2015 when the April 1 snowpack level was 5% of normal, which the authors call an “extreme” event. The paper defines two other types of low-to-no-snow conditions – “episodic low-to-no snow,” or when more than half of a mountain basin experiences low-to-no snow for five consecutive years, and “persistent low-to-no snow,” in which this happens for 10 consecutive years. “Low snow” is defined as when the snowpack (or more precisely, the snow water equivalent, a measure of how much water will be released when the snowpack melts) is in the 30th percentile or lower of the historical peak.
Using these definitions, California could experience episodic low-to-no snow as early as the late 2040s and persistent low-to-no snow in the 2060s according to one high-resolution climate projection. For other parts of the western U.S. persistent low-to-no snow emerges in the 2070s. The authors caution the need for more analyses with a broader set of climate projections to enhance confidence in the timeline for emergence of low-to-no-snow conditions.
The authors describe the climate projections in their study, writing: “Through the middle and end of the 21st century, an increasing fraction of the western U.S. is impacted by snow water equivalent deficits relative to the historical period. In particular, only 8 to 14% of years are classified as low-to-no snow over 1950-2000, compared to 78 to 94% over 2050-2099. In all regions, an abrupt transition occurs in the mid-to-late 21st century.”
Impacts on water resources
The impacts of a low-to-no-snow future extend beyond just decreased streamflow, although that is certainly a significant consequence. In the Sierra Nevada, for example, the amount of water in the snowpack on a typical April 1 is nearly double the surface reservoir storage in California.
“A low-to-no-snow future has massive implications for where and when water is stored in the western U.S.,” said Siirila-Woodburn. “In addition to the direct impacts on recreation and the like, there are a lot of secondary effects on natural and managed systems, from a hydrologic perspective. So that's anything ranging from increased wildfire occurrence to changes in groundwater and surface water patterns and changes in vegetation type and density.”
With less snow and more rain, groundwater levels in mountainous systems may be impacted because snowmelt more effectively infiltrates into the subsurface than rainfall does. Further, less snow at lower elevations will decrease the overall surface area of snowpack stored in the mountains, potentially resulting in less available snowmelt that infiltrates into the ground.
Now for the good news …
The authors’ aim in doing this study was to spur thinking now about adaptation strategies. “We want society to be proactive about these changes in snowpack rather than reactive,” said Rhoades. “Our hope in presenting the literature synthesis of low-to-no snow is so that we can understand the problem in a ‘one-stop shop’ way. Additionally, we highlighted some novel climate adaptation strategies that are coming about through nontraditional academic and water agency partnerships, which will be key parts of a portfolio of adaptation approaches needed to overcome snow loss in a warmer world.”
One such partnership is a Department of Energy-supported project called HyperFACETS, which involves 11 research institutions, including Berkeley Lab, working with water utility managers in California, Colorado, Florida, and Pennsylvania.
The paper also discusses potential adaptation strategies, such as a technique known as managed aquifer recharge, in which excess surface water is stored underground as groundwater for later use. Another relatively new technique, forecast-informed reservoir operations, in which weather and hydrological forecasts are used to inform decisions about retaining or releasing water from reservoirs, was recently shown to increase water storage at Lake Mendocino in California by 33%.
These and other techniques show promise for increasing water supply, but the authors also recommend more cross-collaboration, both among scientists and within society as a whole, to expand the portfolio of climate adaptation strategies.
“We are advocating for the idea of engagement with best scientific practices and more collaboration or partnership between researchers and stakeholders. For example, city managers are concerned with flood control; farmers are concerned with water storage; everyone has their own objectives. Even within science, the disciplines are typically siloed,” said Siirila-Woodburn. “If everyone were working together to manage water rather than working independently for their own purpose, there would be more water to go around.”
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Founded in 1931 on the belief that the biggest scientific challenges are best addressed by teams,Lawrence Berkeley National Laboratory and its scientists have been recognized with 14 Nobel Prizes. Today, Berkeley Lab researchers develop sustainable energy and environmental solutions, create useful new materials, advance the frontiers of computing, and probe the mysteries of life, matter, and the universe. Scientists from around the world rely on the Lab’s facilities for their own discovery science. Berkeley Lab is a multiprogram national laboratory, managed by the University of California for the U.S. Department of Energy’s Office of Science.
DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visitenergy.gov/science.
