Iron-rich rock helps oceans sink atmospheric carbon

First published in Chemistry World, 05.04.18

Adding crushed rocks containing magnesium and iron minerals to seawater allows it to sequester more carbon from the atmosphere, geoscientists have shown.

Oceans are the world’s most efficient carbon store. Around a quarter of all anthropogenic carbon dioxide emissions are sequestered into the sea, and oceans could take in up to 80% of manmade carbon if the process, which usually takes centuries, could be sped up.

A team led by Eric Oelkers from University College London, UK, spread finely milled peridotite – an ultramafic rock that is rich in iron – in tanks of seawater with simulated wave activity. As the powdered rock dissolved it raised the pH of the water, enabling it to react with more atmospheric CO2. The sequestered carbon mineralised into aragonite, a form of calcium carbonate, which sank to the bottom of the tanks.

If powdered peridotite was added to actual oceans, the researchers say, the aragonite would sink to the ocean floor and become sediment, storing carbon permanently. And in nature, aragonite is important for the calcification of corals, so it may even have the added bonus of supporting coral growth.

So far, the approach has only been tried in laboratory simulations. Oelkers says the method needs further scrutiny before it could be seen as a viable way to reduce atmospheric CO2.

‘With upscaling, there are many, many things to consider, some of them unexpected,’ he tells Chemistry World. For example, the extra iron in peridotite rocks could cause plankton blooms. The rocks also contain materials that are harmful to marine life, such as nickel, and it is not clear what impacts these would have on a large scale.

The energy and money required to mine and mill the peridotite also needs to be considered. The researchers propose that the method should be limited to coastal areas where peridotite is common, in order to limit carbon emissions from transport.

Juerg Matter, a geoengineer at the University of Southampton who was not involved in the research, says further refinement of the method could help lower the energy costs of peridotite powder production and save on emissions.

‘The question is really what the acceptable grain size could be,’ he says. ‘Is it really necessary to produce ultrafine particles, or could we tune the process [so] less milling time is required?’

Shipping pollution hotspots mapped with real-time data

First published on SciDev.Net, 30.08.17

Coastal areas around South East Asia suffer the most from pollution caused by ship traffic, according to a global study that estimates shipping emissions based on real-time, local activity for the first time.

The study, published this month (19 August) in Atmospheric Environment, sheds light on forces at play in a region where shipping pollution is believed to cause up to 24,000 deaths a year. The researchers put together a detailed picture of the emissions of around 300,000 commercial vessels for the year 2015. They found  that three of the six most polluted harbours – Singapore, Hong Kong and Shanghai – are in South East Asia.

The Malacca Strait, the Eastern China Sea and the Yellow Sea have the world’s highest concentration of shipping emissions, the authors said.

“In some harbour areas shipping can cause severe health effects and premature deaths.”

Lasse Johansson

They used data from the global Automatic Identification System (AIS), which requires all ships larger than 300 tonnes to regularly report their position. This is significant because it records where ships have been and when, allowing a more precise estimate of shipping pollution compared to previous studies.

The team from the Finnish Meteorological Institute joined around 8 billion AIS data points to cover more than a billion kilometres travelled by commercial ships worldwide in 2015. By combining this data with information on vessel size, engine type and fuel used, they managed to draw a high-resolution image of shipping pollution, particularly highly dangerous small-particle pollution less than 2.5 micrometres in diameter.

The consequences of inhaling these pollutants are serious, says lead author Lasse Johansson, a research scientist at the institute. “In some harbour areas shipping can cause severe health effects and premature deaths.” A 2007 study showed that small-particle emissions from ships lead to an estimated 60,000 premature deaths globally each year.

The situation in South East Asia is compounded by the large number of unregistered local vessels, according to Johansson, which were not included in the study. Globally, the researchers identified  76,000 vessels for which no technical data, such as the ship’s size or type of fuel used, could be obtained.

Together, these vessels travelled a distance that accounts for only 3.5 per cent of all recorded shipping kilometres, but Johansson says their local impact should not be underestimated. “Near coastal cities the [emission] contribution of these vessels can still be larger than the overall contribution might suggest,” he says.

Registered ships were responsible for 93 per cent of small-particle emissions and 91 per cent of the carbon dioxide emissions covered by the study.

Part of the large concentration of shipping emissions in the region is explained by the rapid economic growth of countries in the Association of South East Asian Nations (ASEAN),which is fuelled by  export of consumer goods. The ASEAN nations’ GDP grows by an average 6 per cent annually, according to the OECD, with 74 per cent of the region’s exports travelling by sea  to non-ASEAN countries.

South East Asia also suffers from high shipping emissions because its location exposes it to the densest and most frequent shipping traffic in the world.

Aretha Aprilia, a civil engineer from Indonesia and former coordinator at the UN Environment Programme, tells SciDev.Net that regional efforts to curtail shipping emissions have been “a huge challenge”.

“To date, not much attention has been given to the issues regarding emissions from shipping, and this needs to shift,” says Aprilia. “It is a prerequisite to have more legally binding regulations that are enforced from the countries.”

The study suggests that pollution control areas, where carbon dioxide and fine particle emissions from ships are subject to strict rules, can work if enforced. “Yet these can be costly for ship owners,” says Johansson. He suggests that poorer nations should look at alternatives, like re-routing large ships and planning their infrastructural development in order to mitigate pollution. “For instance in Helsinki, where I live, the cargo terminals were relocated well outside of the city.”

Mud bricks best for cool, green houses, says study

This article was first published on SciDev.Net, 28.06.17

Simple mud concrete bricks provide the most affordable and sustainable houses in the tropics, a Sri-Lankan study suggests.

Comparisons of four different types of walling materials revealed that mud concrete bricks have the lowest environmental impact and keep houses cool. They are also the cheapest, and easiest to dispose of once a house is knocked down.

Researchers compared mud concrete bricks with red bricks (modern fired clay bricks), hollow cement blocks and Cabook, the Sri Lankan name for bricks made from laterite soil, which are common in the tropics. The goal of the study was to find out which types of walling material are the most suitable for constructing affordable houses in the tropics, where population density and poverty are generally high.

“The sustainability of buildings and housing construction is essential to save lives and prevent inadequate living conditions.”

Christophe Lalande

“Why spend more money and destroy the environment more?” asks Rangika Halwatura, a civil engineer at the University of Moratuwa in Sri Lanka, and one of the authors of the paper.

Mud concrete bricks are made from soil in the same way as traditional mud bricks, but contain gravel and sand to improve their strength. The researchers looked at the carbon footprint of all four walling materials, and found that mud concrete bricks were the most environmentally friendly to produce and dispose of.

To check on thermal conductivity the researchers built one-square-metre model houses of the different walling types. Here, they found that red brick kept a house coolest, but mud concrete bricks performed almost as well.

Mud concrete bricks were also found to be the cheapest, at less than US$1,000 in Sri Lanka for an average-sized house, whereas red bricks cost nearly US$3,500.

Mud concrete bricks are widely used in other tropical countries but novel in Sri Lanka. They are popular because they are easy to make and therefore cheap, says Hurryson Moshi, a civil engineer in Tanzania. However, Moshi points out that as people grow wealthier they prefer the red bricks and cement blocks, as these are associated with higher socio-economic status.Walling material graph (FINAL)

Red Brick (modern fired brick), Cement (Hollow Cement Blocks), Cabook (laterite soil brick), Mud (mud concrete brick). Adapted from a graphic ©Udawattha and Halwatura, with permission. 


Moshi agrees with the study’s findings but says that other considerations, such as aesthetics, and symbols of modernity or social status, influence people’s choice of materials. Future studies should also take into account other sources of environmental damage such as deforestation (to produce timber to fire the bricks) or excavation of soil, he added.

In 2015, the government of Sri Lanka launched a programme to build 150,000 houses for the poor. This triggered the researchers’ idea to compare the different types of brick.

According to the United Nations, more than 850 million people around the world live in inadequate slum housing.

According to Christophe Lalande, leader of the UN-Habitat’s Housing Unit, poor neighbourhoods in developing countries are often the most affected by climate change and natural hazards such as storms and rising temperatures.

“The sustainability of buildings and housing construction, being adapted to the local environment, is essential to save lives or prevent inadequate living conditions,” he says.

Bigger isn’t better for energy savings

This article first appeared on Climate News Network, 19.05.17.

LONDON, 19 May, 2017 Advances made in the energy efficiency of heating and transport are lost because of people’s desire to have bigger houses and cars, two research papers have shown.

Researchers have found that houses in England, Australia, Canada, the US and New Zealand are getting bigger as people want more space and extra rooms. This means there is more air to be heated, destroying any climate benefits gained by better heating systems and more efficient insulation, they say.

The study, published in ScienceDirect, found that most house buyers struggled to understand the actual amount of energy their new home would use. Instead, they took information on energy efficiency as a yardstick for consumption.

This means house-owners may think their new, efficient home uses little energy, when in fact it may use more than their neighbours older, smaller houses, says Helen Viggers, a researcher at the public health department of the University of Otago in Wellington, New Zealand, and a co-author of the paper.

Implicit trade-off

“There is general knowledge in the public that both house sizes and insulation standards have increased, and a feeling that both of these are probably ‘good things’,” she told the Climate News Network. “But there is less understanding of the implicit trade-off in energy requirements with increasing house size.”

Viggers is critical of measuring energy usage by square metre, as this “immediately hides [the fact] that larger houses use more energy than smaller ones”.

The New Zealand team also found that larger, stand-alone dwellings featured more wasted” space – such as large lobbies, corner space and little-used hallways. They were designed in a less energy-efficient way than multi-home buildings or small houses.

The findings of the study mirror a 2016 paper by a team of scientists from the University of Barcelona in Spain. They compared Spanish car-buying habits with advances in the energy efficiency of engines, and found that, instead of actually saving energy, people would buy bigger and faster cars.

With little awareness of actual energy consumption,
people involuntarily increase their carbon footprint
while thinking they are helping the environment

The Spanish researchers found that fuel efficiency would have improved by 32% and 40% for petrol and diesel cars respectively, if the cars had stayed the same size. However, they learned that car weight increased by 31% for petrol cars and 26% for diesel between 1988 and 2015, meaning modern cars actually use more fuel than those from three decades ago, despite being more energy efficient.

The New Zealand researchers admitted they did not know whether increases in efficiency directly led to larger-sized consumer objects, or whether other factors influenced people’s buying decisions. But such consumer behaviour has dire consequences for the environment, both teams warn in their papers.

With little awareness of actual energy consumption, people involuntarily increase their carbon footprint while thinking they are helping the environment, Viggers says.

Attractive alternatives

She and her colleagues say policymakers and homebuilders need to come up with better, more attractive smaller homes, and should design some “stunningly good” smaller dwellings.

“They should make the maximum use of the space available, have appropriate room sizes and be aesthetically pleasing,” says Viggers, “so that buyers can see an alternative that might work just as well as a larger dwelling for their family.”

She also supports the creation of mandatory energy certificates that take into account actual consumption, and not just heating efficiency, which would allow those moving into a new home to “make a more informed decision about what that dwelling is worth”.

“Thermal modelling earlier in the design process also forces the designer and builder to explicitly choose the level of energy efficiency they want, and therefore the trade-offs they have to make,” she says. Climate News Network

An alternative future

Research Europe, 12.01.17

Dietmar Lampert, from Austria’s Centre for Social Innovation, hopes that digital science will create a better fit between innovation and society, Inga Vesper reports.

At November’s Web Summit in Lisbon, one innovator took to the stage to demonstrate his face-recognition glasses. “I’m scanning and filing every face in this room,” he told the audience of 15,000. Half of the crowd cheered with excitement. The other half quietly covered up their faces.

It is scenarios such as this that pose crucial questions about whether people are ready to handle the full capabilities of the latest technological inventions. And it is these questions that Dietmar Lampert from the Centre for Social Innovation in Vienna is trying to answer. He wants to understand the effects digital technologies have on society, and propose ways to better prepare people for the latest inventions.

Lampert, who researches digital policy and alternative metrics, sees the issues that have arisen as a result of global digitisation as a two-headed beast.

On the one hand, neither citizens nor policymakers grasp the full extent of the phenomenon because of its intangible nature. “You would never plaster your personal information all over your car for all to see, but in the virtual world people stop being careful because it is harder to connect emotionally,” he says. Law-makers controlling the reach and impact of digital technologies continue to lag behind the technology itself as they remain unaware of how far digital and data-gathering technologies have sneaked into everyday lives, Lampert says.

The digitisation of science offers new opportunities to tackle the problems raised, through the emergence of both open and citizen science. And Lampert says he believes that these hold great scope for a big transition in the future, as combining openness of experiments and results with the involvement of citizens could prepare society better for technological change.

Scientists finally have the means to share data and results widely and immediately, rather than relying on conventional publishing—a necessity when paper documents were the only means of storing and distributing information. Open science means opening the research process up from the start to other partners, including the public and companies, to create innovation and do research that addresses society’s concerns. For researchers, the challenge is to “decide how much, and where, openness makes sense”, he says.

Sharing data will improve the quality of science due to better reproducibility and wider peer review, he claims. “Openness makes sense in science because transparency will give you instant validation and impact.”

Lampert also believes that this will help, ultimately, to shift the research process away from isolated teams working in the confines of a single laboratory, towards close involvement of citizens, policymakers and other scientists. “As researchers, we are still precious about our knowledge. We’ve never been able to break the paradigm,” he says. ”Innovation comes from different ways of looking at something, from not accepting the paradigm.

“Europe has a lot of diversity. Its people can bring something extra to science, and that creates new chances for innovation.”

Traditionally, innovators have been lauded for growing their ideas into large companies, but there has been little requirement for them to think about the social and security implications of inventions. Now, when hundreds of people are involved, scientists need to take charge of ensuring that scientific quality is upheld: for example by providing training in gathering quality data in comparable, shareable formats and thinking about the personal rights of those generating the data, Lampert says.

A truly open and citizen-led movement won’t work for all fields of science, he cautions, especially those involving sensitive data or competitive product development. He says that researchers as well as citizens will have to learn what works and does not work in the open-science process and think of alternative measurements for results.

“For example, scientists would need to change their language, so they don’t solely communicate in jargon,” he says. “It is also a question of who gets the credit. Will the citizens who provided their computing power or pattern-recognition skills be named in the paper? Will scientists be able to move away from counting citations and towards including social impact on their CV?”

He also pleads with policymakers to catch up, as bodies such as the European Commission continue to propose legislation not fit for purpose. Referring to a revision of copyright legislation that aims to protect European inventions, Lampert says that it will clamp down on data sharing and public hosting—totally failing to acknowledge the open-information movement.

“If you own something physical, you’d have a real loss of value if someone took it away,” Lampert says. “But in the world of ideas that’s not always the case. Sharing an idea is what gives it value in the first place.”

Machine-learning algorithm quantifies gender bias in astronomy

04.11.2016 – Original article in Nature

Calculation suggests papers with women first-authors have citation rates pushed down by 10%.

Citation rates in astronomy are stacked against women, a study that uses machine learning to quantify bias has found.

Researchers from the Swiss Federal Institute of Technology in Zurich, Switzerland, estimate that, as a result of gender bias, papers whose first authors are women receive around 10% fewer citations than do those that are first-authored by men.

Gender disparities in citation patterns have been documented across science before. But researchers have not previously tried to quantify how much of the differences are the result of gender bias. For instance, men and women may publish different types of papers; women may work in different scientific fields, and may hold less-senior positions.

But the new paper, which has not yet been peer-reviewed and was posted on the arXiv preprint server on 27 October1, tries to account and correct for these factors. The authors declined to comment on the paper, because they hope to submit it to Nature Astronomy. But other specialists say that the analysis seems solid.

“The novelty of this paper is in dispelling the myth that gender disparity in citation can be attributed to specifics of the paper, rather than to gender,” says Cassidy Sugimoto, an informaticist at Indiana University Bloomington. Sugimoto has also published work on gender bias in science publications2, and says that the paper’s findings are “at once both terrible and terrific”.

Estimating gender bias

For their study, the researchers analysed 200,000 papers in 5 journals from 1950 to 2015. First, they trained a machine-learning algorithm to accurately calculate the citations for each paper first-authored by a man using as many non-gender-related factors as possible — such as the journal, field and year in which the paper was published, where the first author was located and for how many years that author had been publishing.

Then they unleashed their algorithm on the papers with female first authors. This set of papers (from 1985 onwards) had actually received around 6% fewer citations than their male-authored counterparts. But the algorithm predicted that the papers should have got 4% more citations than did those authored by men.

The authors say that the result is their “best effort” to measure gender bias, but that their results should be taken with care, because other factors might need to be weighed into their algorithm.

“This means women and men of equal quality will have unequal records,” says Meg Urry, director of Yale Center for Astronomy and Astrophysics in New Haven, Connecticut, who gave advice to the Swiss researchers as they conducted their study.  She adds that being cited less is likely to result in fewer grants, invitations to talks and recommendation letters. “Given how heavily our hiring process depends on these metrics, it’s not surprising that women have not reached equity in academia,” she says.

Suppressed citations

A good track record of citations is essential for research career progression, so the findings could go some way towards explaining the dearth of women in senior academic positions, says Karen Masters, an astronomer at the University of Portsmouth, UK.

“I have had people tell me that they won’t shortlist for permanent faculty jobs unless the candidates have 100 citations on a first-author paper,” she says. “So, I think it’s really in getting on shortlists for jobs that this suppression in citation rate for women is going to be hurting them.”

The new study also notes that women publish 19% fewer articles than men in the 7 years after their first published paper. Astrophysicist Anna Scaife, who heads the Interferometry Centre of Excellence at Jodrell Bank observatory in the United Kingdom, says that this factor could be even more damaging than the low citation rates. “The 4–6 years following PhDs are crucial for producing the output that contributes to their first application for a permanent position,” she says.

To address the problem, Masters suggests a solution straight from the astronomer’s toolbox. The number of citations that women receive, she says, could be multiplied by 1.1 to eradicate the intrinsic bias. “We often correct systematic biases like that empirically in trends we view in astronomy,” she says. “So I think this could be treated similarly.”