Why are some birds more intelligent than others?

Brain size is only part of the answer – and time in the nest may be key

Peer-Reviewed Publication

MCGILL UNIVERSITY 

video Grackle dips dog pellets to so [VIDEO] | EurekAlert! Science News Releases

VIDEO: A CARIB GRACKLE AT THE BELLAIRS RESEARCH INSTITUTE IN BARBADOS DUNKS DOG PELLETS TO MAKE THEM MORE EDIBLE. view more 

CREDIT: LOUIS LEFEBVRE

If you’ve ever seen a grackle steal your dog pellets or a starling peck open a garbage bag, you get a sense of that some birds have learned to take advantage of new feeding opportunities – a clear sign of their intelligence. Scientists have long wondered why certain species of birds are more innovative than others, and whether these capacities stem from larger brains (which intuitively seems likely) or from a greater number of neurons in specific areas of the brain.

It turns out that it’s a bit of both, according to a recent study by an international team that included members from McGill University published in Nature Ecology and Evolution.

More neurons in the right place tied to greater intelligence in birds

The researchers used a new technique to estimate the number of neurons in a specific part of the brain called the pallium in 111 bird species. The pallium in birds is the equivalent of the human cerebral cortex, which is involved in memory, learning, reasoning, and problem-solving, among other things. When these estimates about neuron numbers in the pallium were combined with information about over 4,000 foraging innovations, the team found that the species with the higher numbers of neurons in the pallium were also likely to be the most innovative.

Longer development time in nest a key factor

“The amount of time fledglings spend in the nest as their brains develop might also play a crucial role in the evolution of intelligence,” says McGill University Emeritus Professor Louis Lefebvre who spent more than 20 years gathering examples of foraging innovations. “Larger species of crows and parrots, that are known for their intelligence, spend longer in the nest, which allows more time for the brain to grow and accumulate pallial neurons.”

The results of the study help to reconcile previously opposed views of the evolution and significance of brain size and show how a life-history perspective helps to understand the evolution of cognition.

“Neuron numbers link innovativeness with both absolute and relative brain size in birds” by Sol D., Olkowicz, S., Sayol, F. et al in Nature Ecology and Evolution

https://doi.org/10.1038/s41559-022-01815-x

 

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JOURNAL

Nature Ecology & Evolution

DOI

10.1038/s41559-022-01815-x 

ARTICLE TITLE

Neuron numbers link innovativeness with both absolute and relative brain size in birds

Research suggests that change in bird coloration is due to climate change

The study was carried out over a 15-year period in the south of France through a partnership between scientists from the UPV/EHU-University of the Basque Country and the Centre d'Écologie Fonctionnelle et Évolutive (CEFE-CNRS) in Montpellier

Peer-Reviewed Publication

UNIVERSITY OF THE BASQUE COUNTRY

 

IMAGE: MORE THAN 5,800 OBSERVATIONS ON THE COLOURING AND OTHER CHARACTERISTICS OF THE BLUE TITS LIKE THIS ONE WERE MADE BETWEEN 2005 AND 2019 view more 

CREDIT: DAVID LÓPEZ-IDIÁQUEZ.

The work, which was conducted over a 15-year period (2005-2019) through a partnership between scientists from the UPV/EHU and the Centre d'Ecologie Fonctionnelle et Évolutive in Montpellier (CEFE-CNRS), focused on two populations of blue tits in the south of France, one located on the outskirts of Montpellier and the other in the northwest of the island of Corsica. 

Each year between 2005 and 2019, all breeding blue tits in each population were captured. As a result, researchers from the two institutions were able to gather more than 5,800 observations on the colouring and other characteristics of the blue tits.  

The blue tit is characterised by its striking colouring: a blue crest and a yellow breast. The results obtained in the study show a decrease in both populations of blue and yellow colouration between 2005 and 2019. In other words, the blue crests and yellow breasts of blue tits in these two populations are on average less colourful right now than when the research began.  

“Our work suggests that environmental changes, and specifically climate change, could be the main reason why birds such as the blue tit are undergoing a change in their physical features, more specifically in the brightness and intensity of their colouration,” said David López-Idiáquez, researcher in the UPV/EHU's Department of Plant Biology and Ecology.   

“A negative trend in terms of brightness and intensity of plumage colouration in both sexes and populations has been observed, although in Corsica this change is more associated with climate,” explained López.” The change in plumage colour seems to be the result of a combination of a rise in temperature (1.23ºC) and a fall in rainfall (0.64 mm), so climate change would be the potential cause of this difference,” he said.   

Change in species mating patterns 

It may appear to be a purely aesthetic change, but just the opposite is true, as this change in plumage may have an effect on the “mating patterns” of the species. “In these birds, traits such as colouring function as signals to indicate to other individuals the quality of the specimen, which are decisive, for example, when it comes to breeding,” explained David López. 

“This study was possible thanks to the continuous monitoring of the two blue tit populations for more than 15 years, which highlights the importance of long-term studies to understand the effects of climate change on the ecosystems around us,” he said. 

When there is a variation in the territory, animal populations have 4 options: the first is to undergo genetic change; the second is to undergo plastic change (change in physical characteristics without genetic changes); the third is to migrate; and the last, to disappear. “It is important to stress that this change is not genetic but plastic, one of the ways of adapting to new environmental conditions,” he pointed out. 

Change in our environment 

“Given that our environment is quite similar, albeit less hot, our birds may be undergoing the same change,” surmised David. “In any case, there are only four studies of this type in the world, and none of them has been carried out in the Basque Country; I think it would be very interesting to carry out more research like this not only on a Basque level, but also on a national level,” he added.  

David López-Idiáquez (Villajoyosa, 1988) is a postdoctoral researcher at the University of the Basque Country and at the Centre d'Ecologie Fonctionnelle et Évolutive in Montpellier. His research interests focus on understanding how the heterogeneity of environmental conditions alters evolutionary dynamics, especially in ornamental traits. After graduating from the UPV/EHU, he was awarded a PhD in Ecology from the Autonomous University of Madrid in conjunction with the Museum of Natural Sciences in Madrid. 

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JOURNAL

The American Naturalist

DOI

10.1086/719655 

ARTICLE TITLE

Long-Term Decrease in Coloration: A Consequence of Climate Change?

New study reveals that climate change will severely impact bird species by 2080

For immediate release: Wednesday 3 August 2022

Peer-Reviewed Publication

DURHAM UNIVERSITY

-With pictures-

Bioscientists from Durham University, UK and Senckenberg Biodiversity and Climate Research Centre, Germany have predicted in their latest research that bird communities will change worldwide in 2080 due to climate change, largely as result of shifting their ranges.

For the projections of the bird communities to the year 2080, the team of scientists related past bird distributions to climate data and then applied these relationships to two future climate scenarios – based on low and medium greenhouse gas emissions – to predict changes in species distributions.

The team looked not only at changes in numbers of species in areas but also at the types of species that would occur. To summarise changes in species types they calculated something called phylogenetic diversity that summarises how many different types of birds would occur.

For example, a community that had a lot of closely-related species, such as insect-eating songbirds, would have a much lower phylogenetic diversity score than a community that included a mix of more distantly-related species, for example songbirds plus other species such as birds of prey, partridges or gulls.

They investigated how the communities of birds all over the world could change in the future and discovered that that climate change will not only affect species numbers but will also have profound effects on phylogenetic diversity and community composition.

Examples of bird species that are currently increasing phylogenetic diversity in the UK, probably largely driven by climate change, include European bee-eaters, a type of insect-eating bird, black-winged stilts and spoonbills, all of which normally breeds further south in Europe but now occasionally breeds in the UK. Bee-eaters are only distantly related to other current UK-breeding bird species. Similarly, newly breeding species such as spoonbills and black-winged stilts have added to the phylogenetic diversity of birds in the UK in recent years.

The researchers evaluated data for a total of 8,768 bird species globally to predict how many different lineages could be lost regionally, or added, as species respond to climate change by shifting their distributions.

Although the researchers project species losses to be most common in tropical and subtropical areas, phylogenetic restructuring of species communities is expected to occur around the world.

Their study emphasise that preservation of local phylogenetic diversity can be a key to the resilience of biological diversity to environmental changes.

Their full study has been published in the journal Proceedings of the Royal Society B.

“In our study, we examined the effects of global warming on the regional distribution of terrestrial birds around the world. The focus was on the effects on species richness as well as on various aspects of phylogenetic diversity, primarily how closely related the species are to each other”, said lead author of the study, Dr. Alke Voskamp of Senckenberg Biodiversity and Climate Research Centre.

Co-author of the study, Professor Stephen Willis of Durham University, said: “The diversity of lineages is very often related to the diversity of traits that species possess and thus to their roles and functions in ecosystems. For example, species from more distant lineages often have different beak types, and hence eat different types of food. Change means that the ecosystem functions that birds perform in an area may also change in the future, with potential consequences for food webs, seed dispersal and plant pollination.”

The research highlights the importance of considering diverse measures in climate impact assessments. It has been funded by the German Federal Ministry of Education and Research, the Bavarian State Ministry of Science and Arts, German Research Foundation and Leibniz Association and stems from initial work funded by Durham University. 

ENDS

Media Information

Professor Stephen Willis of Durham University is available for interview and can be contacted on s.g.willis@durham.ac.uk.   

Alternatively, please contact Durham University Communications Office for interview requests on communications.team@durham.ac.uk.

Source information

‘Projected climate change impacts on the phylogenetic diversity of the world's terrestrial birds: more than species numbers’, (2022), A. Voskamp, C. Hof, M. Biber, K. Böhning-Gaese, T. Hickler, A. Niamir, S. Willis and S. Fritz, Proceedings of the Royal Society B.

Full paper can be accessed here: https://royalsocietypublishing.org/doi/10.1098/rspb.2021.2184

Graphics

Associated image is available via the following link: https://www.dropbox.com/sh/qs8ftp9nu8bkwqb/AAD_qxoC4a-yluR3zet12djea?dl=0

Credit: Kieran Lawrence

Useful Web Links 

Professor Stephen Willis staff profile: https://www.durham.ac.uk/staff/s-g-willis/

Department of Biosciences: https://www.durham.ac.uk/departments/academic/biosciences/

Senckenberg Biodiversity and Climate Research Centre: https://www.senckenberg.de/en/institutes/sbik-f/

About Durham University

Durham University is a globally outstanding centre of teaching and research based in historic Durham City in the UK.

We are a collegiate university committed to inspiring our people to do outstanding things at Durham and in the world.

We conduct boundary-breaking research that improves lives globally and we are ranked as a world top 100 university with an international reputation in research and education (QS World University Rankings 2023).

We are a member of the Russell Group of leading research-intensive UK universities and we are consistently ranked as a top 10 university in national league tables (Times and Sunday Times Good University Guide, Guardian University Guide and The Complete University Guide).

For more information about Durham University visit: www.durham.ac.uk/about/

END OF MEDIA RELEASE – issued by Durham University Communications Office.

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JOURNAL

Proceedings of the Royal Society B Biological Sciences

SUBJECT OF RESEARCH

Animals

SCI FI JOURNAL

IOP Publishing announce Nuclear Fusion will become fully Open Access

Business Announcement

IOP PUBLISHING

 

IMAGE: IOPP ANNOUNCE JOURNAL NUCLEAR FUSION WILL BECOME FULLY OPEN ACCESS FROM 2023 view more 

CREDIT: N/A

IOP Publishing (IOPP) has announced that the International Atomic Energy Agency (IAEA) journal Nuclear Fusion (NF) will become fully open access to reflect the increasing demand for more accessible and open science and funders’ mandates requiring authors to publish their work in open access (OA) journals. 

From January 2023, all articles published in NF, the world-leading journal specialising in nuclear fusion, will be made open access making the content immediately and openly accessible to scientists and the public alike. 

Since 2002, IOPP has co-published the journal with the IAEA, the world’s central intergovernmental forum for scientific and technical co-operation in the nuclear field. Since then, NF has published more than 6,000 articles, received submissions from over 50 countries, and has been cited nearly 19,000 times. The journal is a central platform for the dissemination of high-quality, peer-reviewed research in the field of controlled thermonuclear fusion. 

Miriam Maus, publishing director at IOP Publishing says: “We believe conducting science more openly can accelerate scientific discovery. IOP Publishing’s commitment to open access dates back to 1998, with the launch of the world’s first fully open access physics journal. We look forward to establishing a viable and affordable open access publication route for the nuclear fusion community.” 

Under the fully gold open access model, NF will provide authors with the widest possible global audience, increasing the reach and impact of nuclear fusion research. The journal will continue to support authors and reviewers to publish excellent research and deliver rigorous and timely peer review. 

OA publishing in NF will be funded through Article Publication Charges of £2000 per article. However, IOPP is committed to greater inclusivity of researchers and acknowledges the importance of author choice. Supporting researchers from low and lower-middle income economies, as categorised by the World Bank, IOPP offers a 75% hardship waiver for researchers whose institutions are facing financial difficulties and would not otherwise be able to publish in the journal. 

More information about this change to NF, fees and discounts, and what it means for authors are available here. 

Pandemic has put long-haul pilots in a stressful tailspin

Reports and Proceedings

UNIVERSITY OF SOUTH AUSTRALIA

Stress levels among commercial airline pilots have skyrocketed during the COVID-19 pandemic, putting their mental health at risk, according to a new study by the University of South Australia.

Survey data collected from 49 commercial pilots in the Asia Pacific region, Europe and North America reveals that 75.5 per cent of pilots are stressed about their uncertain futures, anti-social working hours and the “divergence in values” between pilots and management.

The findings should be a wake-up call to the aviation industry to install targeted workplace measures to support pilots and mitigate pilot stress, the researchers told a recent conference

UniSA Senior Lecturer in Aviation, Dr Silvia Pignata, says pilots have traditionally been reluctant to talk about their stress levels, mainly due to concerns about medical certifications that require them to be both physically and mentally healthy*.

Grounded planes during the pandemic and the ongoing disruption to flight schedules have added to pilots’ stress, with between 46-82 per cent of pilots impacted by the COVID-19 pandemic.

“The issue of work stress has been neglected by the aviation industry, even before the pandemic,” Dr Pignata says.

“Due to consumer demand for travel, airlines strive to keep their fleet in the air for as long as possible. Higher turnover rates mean more flight legs, increased workloads and higher stress levels for pilots. The uncertainty around the industry and conflicts with management over the past two years has just added to their stress.”

Prior studies have highlighted the mental fatigue that short haul pilots experience due to flying multiple routes in a typical day, where pilots’ heart rates can reach 88bpm during landing. Repeated take-offs and landings may exacerbate this stress.

Long-haul flights also play havoc with pilots’ body clocks, flying across multiple time zones and working irregular hours. The UniSA study reveals that long haul pilots reported the highest levels of stress and medium haul pilots reported the lowest stress levels. While long haul pilots were stressed by quarantine restrictions and enforced distance from family, some short haul pilots who were temporarily grounded due to the industry shutdown reported that they enjoyed time with their family, improving their wellbeing.

Notes for editors

“Is There a Relationship Between Pilot Stress and Short- and Long- Haul Flights?” was presented to the International Conference on Human-Computer Interaction in June 2022.

The authors of the paper are Dr Silvia Pignata, and aviation students Khai Sheng Sew, Kin Wing Lo and Lucus Yap, all from the University of South Australia

*In 2015, a Germanwings pilot who had kept his mental illness from his employer, committed suicide by deliberately taking down a plane with 150 passengers on board.

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DOI

10.1007/978-3-031-06086-1_33 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Is there a relationship between pilot stress and short- and long- haul flights?

Race discrimination linked to heightened risk of underweight and premature babies

Adds to existing evidence that discrimination is a risk factor for poor health outcomes

Peer-Reviewed Publication

BMJ

Experience of race discrimination on the basis of ethnicity, skin colour, or nationality is linked to a heightened risk of having an underweight and/or premature baby, finds a pooled data analysis of the available evidence, published in the open access journal BMJ Global Health.

The findings add to the existing evidence that race discrimination is a risk factor for poor health outcomes, say the researchers.

For several decades, race has been recognised as a social determinant of health and a risk factor for numerous diseases.  The evidence increasingly suggests that upstream social, environmental, economic and political factors are fundamental drivers of health inequities, and that it is often racism, rather than race, that is the root cause.

For example, maternal death rates among Black and Indigenous women in the USA are 2–3 times higher than those of White women. Similarly, in the UK, maternal death rates are 2–4 times higher among Black and Asian women than they are among White women.

To explore the existing patterns of racial disparities in pregnancy outcomes, the researchers searched 8 electronic databases, looking for relevant studies on self-reported race discrimination and premature birth (before 37 weeks), low birthweight, and high blood pressure associated with pregnancy, and published up to January 2022.

In all, the results of 24 studies were included in the final analysis, with the number of participants in each study ranging from 39 to 9470. Most (20) studies were carried out in the US.

Study participants were of different racial and ethnic backgrounds, including Black or African American, Hispanic, non-Hispanic white, Mãori, Pacific, Asian, Aboriginal, Romani, indigenous German and Turkish.

The pooled data analysis showed that for all the outcomes studied, experience of race discrimination was associated with a heightened risks of premature birth and giving birth to a small-for-gestational age baby.

The overall odds of a premature birth were estimated to be 40% higher. When low quality studies were excluded, the odds of a premature birth were reduced but still 31% higher. And while not statistically significant, the overall odds of a small-for-gestational age baby were estimated to be 23% higher.

Similar results were obtained when further analyses of selected data were carried out.

The researchers acknowledge that many of the studies included in the pooled data analysis were of low quality, and that most were based in the USA, and included few marginalised racial or ethnic groups other than African Americans. As such, they may not be more widely applicable to other ethnic groups and cultural settings.

Nevertheless, they point out: “Our findings align with existing evidence on perceived racial discrimination as an important risk factor for adverse pregnancy outcomes.”

They explain: “Pervasive in people’s day-to-day lives, racism has far reaching implications on the experiences of racialised individuals. As an upstream factor, it shapes other social determinants of health such as employment, poverty, education and housing. 

“Relating more directly to health, racism can impact what services and resources are available, such as referral to specialist care, access to health insurance and access to public health services.”

The researchers highlight various approaches to counter the effects of racism on health outcomes, including the need to improve the training of clinicians.

This can be done by: “universally removing well-documented examples of racial bias which continue to perpetuate health inequities,” they suggest. 

“This includes the lack of teaching on dermatology and differential disease presentations in non-White individuals, inaccuracies in pulse oximetry technology, unsubstantiated race-based adjustments to measuring renal function, and inadequate teaching around individual biases and the social drivers of health inequities.”

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JOURNAL

BMJ Global Health

DOI

10.1136/bmjgh-2022-009227 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Racial discrimination and adverse pregnancy outcomes: a systematic review and meta-analysis

Brazilian scientists reveal method of converting methane gas into liquid methanol

The strategy was tested at the Federal University of São Carlos. The conversion took place under ambient temperature and pressure conditions, which could enable methane, a potent greenhouse gas, to be used to produce fuel.

Peer-Reviewed Publication

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO

 

IMAGE: THE CONVERSION TOOK PLACE UNDER AMBIENT TEMPERATURE AND PRESSURE CONDITIONS, WHICH COULD ENABLE METHANE, A POTENT GREENHOUSE GAS, TO BE USED TO PRODUCE FUEL. view more 

CREDIT: UFSCAR

A group of researchers has succeeded in converting methane into methanol using light and dispersed transition metals such as copper in a process known as photo-oxidation. According to an article reporting the study published in Chemical Communications, the reaction was the best obtained to date for conversion of methane gas into liquid fuel under ambient conditions of temperature and pressure (25 °C and 1 bar respectively).

The term bar as a unit of pressure derives from the Greek word for weight (baros). One bar is equivalent to 100,000 Pascals (100 kPa), which is very close to the standard atmospheric pressure at sea level (101,325 Pa).

The results of the study are an important step in making natural gas available as an energy source for the production of alternative fuels to gasoline and diesel. Although natural gas is considered a fossil fuel, its conversion into methanol emits less carbon dioxide (CO2) than other liquid fuels in the same category.

In Brazil, methanol plays a key role in biodiesel production and in the chemical industry, which uses it to synthesize many products.

Furthermore, methane capture from the atmosphere is crucial to mitigate the adverse effects of climate change, as the gas has 25 times the potential of CO2, for example, to contribute to global warming.

“There’s a great debate in the scientific community about the size of the planet’s methane reserves. According to some estimates, they may have double the energy potential of all other fossil fuels combined. In the transition to renewables, we’ll have to tap into all this methane at some point,” Marcos da Silva, first author of the article, told Agência FAPESP. Silva is a PhD candidate in the Physics Department of the Federal University of São Carlos (UFSCar).

The study was supported by FAPESP via two projects (20/14741-6 and 21/11162-8), by the Higher Research Council (CAPES, an agency of the Ministry of Education), and by the National Council for Scientific and Technological Development (CNPq, an arm of the Ministry of Science, Technology and Innovation).

According to Ivo Freitas Teixeira, a professor at UFSCar, Silva’s thesis advisor and last author of the article, the photocatalyst used in the study was a key innovation. “Our group innovated significantly by oxidizing methane in a single stage,” he said. “In the chemical industry, this conversion occurs via the production of hydrogen and CO2 in at least two stages and under very high temperature and pressure conditions. Our success in obtaining methanol under mild conditions, while also expending less energy, is a major step forward.”

According to Teixeira, the results pave the way for future research into the use of solar energy for this conversion process, potentially reducing its environmental impact still further.

Photocatalysts 

In the laboratory, the scientists synthesized crystalline carbon nitride in the form of polyheptazine imide (PHI), using non-noble or earth-abundant transition metals, especially copper, to produce active visible-light photocatalysts. 

They then used the photocatalysts in methane oxidation reactions with hydrogen peroxide as an initiator. The copper-PHI catalyst generated a large volume of oxygenated liquid products, especially methanol (2,900 micromoles per gram of material, or µmol.g-1 in four hours).

“We discovered the best catalyst and other conditions essential to the chemical reaction, such as using a large amount of water and only a small amount of hydrogen peroxide, which is an oxidizing agent,” Teixeira said. “The next steps include understanding more about the active copper sites in the material and their role in the reaction. We also plan to use oxygen directly to produce hydrogen peroxide in the reaction itself. If successful, this should make the process even safer and economically viable.”

Another point the group will continue to investigate relates to copper. “We work with dispersed copper. When we wrote the article, we didn’t know whether we were dealing with isolated atoms or clusters. We now know they’re clusters,” he explained.

In the study, the scientists used pure methane, but in future they will extract the gas from renewables such as biomass. 
According to the United Nations, methane has so far caused about 30% of global warming since the pre-industrial age. Methane emissions from human activity could be reduced by as much as 45% in the decade ahead, avoiding a rise of almost 0.3°C by 2045.

The strategy of converting methane into liquid fuel using a photocatalyst is new and not available commercially, but its potential in the near term is significant. “We began our research over four years ago. We now have far better results than those of Professor Hutchings and his group in 2017, which motivated our own research,” Teixeira said, referring to a study published in the journal Science by researchers affiliated with universities in the United States and United Kingdom, and led by Graham Hutchings, a professor at Cardiff University in Wales.

About São Paulo Research Foundation (FAPESP)

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe

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JOURNAL

Chemical Communications

DOI

10.1039/D2CC01757A 

ARTICLE TITLE

Selective methane photooxidation into methanol under mild conditions promoted by highly dispersed Cu atoms on crystalline carbon nitrides

First global map of cargo ship pollution reveals effects of fuel regulations

"Ship tracks" in clouds also help explain how particulate matter interacts with clouds and affects global temperatures

Peer-Reviewed Publication

UNIVERSITY OF MARYLAND BALTIMORE COUNTY

A new study in Science Advances led by UMBC’s Tianle Yuan used satellite data from 2003 – 2020 to determine the effect of fuel regulations on pollution from cargo ships. The research team’s data revealed significant changes in sulfur pollution after regulations went into effect in 2015 and 2020. Their extensive data set can also contribute to answering a bigger question: How do pollutants and other particles interact with clouds to affect global temperatures overall?

Tiny particles in the atmosphere, which are called aerosols and include pollution, can harm human health, but they also often have a cooling effect on the planet because of the way they interact with clouds. However, estimates of the extent of that effect range by a factor of 10—not very precise for something so important.

“How much cooling the aerosols cause is a big unknown right now, and that’s where ship tracks come in,” says Yuan, an associate research scientist at the Goddard Earth Sciences Technology and Research (GESTAR) II Center.

Sea of data

When pollutant particles from ships enter clouds low in the atmosphere, they decrease the size of individual cloud droplets without changing the total volume of the cloud. That creates more droplet surface area, which reflects more energy entering Earth’s atmosphere back to space and cools the planet.

Instruments on satellites can detect these differences in droplet size. And the air over the ocean is generally very clean, making the relatively narrow ship tracks that snake across the ocean easy to pick out. “Most of the original cloud is unpolluted, and then some of it is polluted by the ship, so that creates a contrast,” Yuan explains.

While ship tracks can be relatively obvious in satellite data, you have to know where to look and have the time and resources to search. Before advances in computing power and machine learning, Yuan says, Ph.D. students could focus their entire thesis on identifying a group of ship tracks in satellite data.

“What we did is automate this process,” Yuan says. His group “developed an algorithm to automatically find these ship tracks from the sea of data.” 

This huge advance allowed them to generate a comprehensive, global map of ship tracks over an extended period (18 years) for the first time. Next, they will share it with the world—opening the door for anyone to dig into the data and make further discoveries.

Disappearing act

Even before pollution-limiting regulations were put into place, Yuan and his colleagues found that ship tracks didn’t occur everywhere ships were traveling. Only areas with certain types of low cloud cover had ship tracks, which is useful for adjusting the role of clouds in climate models. They also found that after Europe, the U.S., and Canada instated Emission Control Areas (ECAs) along their coastlines in 2015, ship tracks nearly disappeared in those regions, demonstrating the efficacy of such regulations for reducing pollution in port cities.

However, shipping companies didn’t necessarily reduce their pollution output across the board. Instead, they made changes to adapt to the new rules. Ports in northern Mexico (not part of the ECA system) saw increased activity, and pollution “hot spots” built up along the boundaries of the ECAs as ships altered their routes to spend as few miles as possible inside the restrictive zones. 

In 2020, though, an international agreement set a much more restrictive standard for shipping fuel across the entirety of global oceans, rather than only near coastlines. After that, the only ship tracks the team’s algorithm could detect were those in the cleanest clouds. In clouds with even mild background pollution, the presumed ship tracks blended right in.

Climate conundrum

It seems obvious that reducing pollution from ships would produce a net benefit. However, because particles (such as shipping pollution) have a cooling effect when interacting with clouds, reducing them significantly could contribute to a problematic uptick in global temperatures, Yuan says. 

That’s another reason it’s important to firm up the degree to which particulate pollution cools the planet. If the cooling effect of these pollutants and other particles is significant, humans will need to balance the need to prevent extensive warming with the need to reduce pollution where people and other species live—which creates difficult choices.

“Ship pollution alone can create a substantial cooling effect,” Yuan says, “because the atmosphere over the ocean is so clean.” There is a physical limit to how small cloud droplets can get, so at a certain point, adding more pollution doesn’t increase the clouds’ cooling effect. But over the ocean, because the background is largely unpolluted, even a small amount of pollution from ships has an effect. 

Ocean pollution is also an outsize driver of the cooling effect of aerosols, because low clouds, which are most conducive to creating ship tracks, are more common over water than on land. And, as Yuan reminds us, “the ocean covers two-thirds of the Earth’s surface.”

The bigger picture

Moving forward, Yuan and his colleagues are helping address this conundrum by continuing their work to define more precisely the role clouds play in climate. “We can take advantage of the millions of ship track samples we have now to start to get hold of the overall aerosol-cloud interaction problem,” Yuan says, “because ship tracks can be used as mini-labs.”

By analyzing data from a relatively simple and well-controlled system—narrow ship tracks running through very clean clouds—they can come to conclusions they can be confident about.”

Other research teams can also use the team’s data set and algorithm to come to their own conclusions, amplifying the potential public impact of this work. That spirit of collaboration will help scientists and communities determine how best to approach global challenges like pollution and temperature change.

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JOURNAL

Science Advances

DOI

10.1126/sciadv.abn7988 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Global reduction in ship-tracks from sulfur regulations for shipping fuel

New technology can help combat climate crisis

Scientists have created a novel technology that can help to tackle climate change and address the global energy crisis

Peer-Reviewed Publication

NORTHUMBRIA UNIVERSITY

 

IMAGE: PHOTOCATALYST SHEET CONTAINING LIGHT-ABSORBING PARTICLES AND BACTERIA view more 

CREDIT: N/A

Scientists have created a novel technology that can help to tackle climate change and address the global energy crisis.

Northumbria University’s Dr Shafeer Kalathil is among a team of esteemed academics behind the project, which uses a chemical process that converts sunlight, water and carbon dioxide into acetate and oxygen to produce high-value fuels and chemicals powered by renewable energy.

As part of the process, bacteria are grown on a synthetic semiconductor device known as a photocatalyst sheet, which means that the conversion can take place without the assistance of organic additives, creation of toxins or use of electricity.

The aim of the project is to curtail the rise in atmospheric CO2 levels, secure much-needed green energy supplies and alleviate the global dependence on fossil fuels. A paper detailing the findings of the team’s research has been published in scientific journal Nature Catalysis.

Dr Kalathil, Vice Chancellor’s Senior Fellow, is working on the project with Erwin Reisner, Professor of Energy and Sustainability at the University of Cambridge, Dr Qian Wang, associate professor at Nagoya University in Japan, and partners from Newcastle University.

Dr Kalathil said: “Several incidents have demonstrated the fragility of the global energy supply, such as recent soaring gas prices in UK, the outbreak of conflicts and civil wars in the Middle East and the ecological and humanitarian threat of a nuclear meltdown in Fukushima, Japan. The search for alternative energy sources is therefore of major global importance.

“Our research directly addresses the global energy crisis and climate change facing today’s society. We need to develop new technologies to address these grand challenges without further polluting the planet we live on.

“There has been an increase in electricity generation from renewable sources such as wind and solar, but these are intermittent in nature. To fill the gap when the wind doesn’t blow or the sun doesn’t shine, we need technologies that can create storable fuels and sustainable chemicals. Our research addresses this challenge head on.

“As well as securing additional much-needed energy supplies, our sustainable technology can reduce greenhouse gas emissions and play a key role in the global drive to achieve net zero.”

The project was supported by funding from the European Research Council, UK Research and Innovation, and Research England’s Expanding Excellence in England Fund, which supports higher education research units and departments to expand and increase their activity. The Research England grant was secured via the Hub for Biotechnology in the Built Environment (HBBE), a joint initiative between Northumbria and Newcastle University, which has received a total of £8 million from Research England to conduct project work. Launched in August 2019,  the HBBE develops biotechnologies to create environmentally friendly buildings that can metabolise waste, reduce pollution, generate sustainable energy and improve human health and wellbeing.

Dr Kalathil, who is heavily involved with the HBBE, said: “The aims of the HBBE fit with what we’re trying to achieve with our research – to address key environmental concerns facing our society today and in the future. This emerging field of research represents an interdisciplinary approach that combines the strengths of microbes, synthetic materials and analytical techniques for chemical transformation, and provides an excellent platform to produce high-value, environmentally friendly fuels and chemicals at scale. We’re already in discussions with international chemical manufacturers and cosmetics producers, and the ultimate aim is to develop our technology on a commercial scale.”

There are multiple benefits of this research, which is designed to inspire budding scientists to design and develop new technologies for sustainable energy production. The work also highlights the expertise of Northumbria’s Department of Applied Sciences, which covers an exciting and extensive portfolio of subjects including biology, biomedical sciences, chemistry, forensic science, food and nutritional sciences. Many of Northumbria’s courses in this field are professionally accredited by the Royal Society of Chemistry, Institute of Biomedical Science, the Chartered Society of Forensic Science and Association for Nutrition, or approved by statutory regulatory bodies such as the Health & Care Professions Council.

Northumbria University has recently gained reinforcement of its already outstanding reputation for excellence in research, having been ranked 8th in the UK for research power for professions allied to health, such as cellular and molecular sciences, in the latest Research Excellence Framework (REF2021).

The paper, ‘Bacteria–photocatalyst sheet for sustainable carbon dioxide utilization’, is published in scientific journal Nature Catalysis. The paper and a full list of authors can be found at https://www.nature.com/articles/s41929-022-00817-z.

For more information, visit www.northumbria.ac.uk and @ReisnerLab on Twitter. 

  

CAPTION

Schematic diagram showing that the sunlight-driven bacteria-modified photocatalyst sheet provides acetate for a biohybrid electrochemical system to generate current and close the carbon cycle

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JOURNAL

Nature Catalysis

DOI

10.1038/s41929-022-00817-z 

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Bacteria–photocatalyst sheet for sustainable carbon dioxide utilization