GeoLog

Energy, Resources and the Environment

Cities of the future

Cities of the future

Over half the world’s population lives in cities. Many a metropolis rises high above carpets of concrete and tarmac, vibrant, bustling, and prosperous. But this urban environment comes with many a problem. From poor air quality to hazardous temperatures, there are several dangers present in urban environments. Scientists speaking at the European Geosciences Union General Assembly in Vienna earlier this year have been testing designs that could change cityscapes and tackle the challenges of urban living. The solution, it seems, is making these areas greener.

As well as making cities more aesthetically pleasing, more vegetated urban environments come with a wealth of benefits, including improving wellbeing, absorbing noise and creating new habitats. With horizontal space at a premium, scientists and engineers are looking to city walls to make environments greener, exploring how growing vertical gardens can help address the challenges associated with urban environments.

“We should have much more vegetation than we currently have. That’s the source of a number of problems,” says Fulvio Boano an environmental engineer at Politecnico di Torino, Torino, Italy.

The problems include a phenomenon known as the urban heat island effect. Cities are typically warmer than the surrounding countryside. Dense networks of dark roads and pavements absorb more solar radiation than natural vegetation, and high-rise buildings can also interfere with natural cooling effects, like wind. Combined, these urban features make cities warmer than their surroundings. The effect is more pronounced at night, leaving urban areas several degrees warmer than their suburban counterparts, resulting in an urban heat island.

The difference may only be a few degrees, but the impact that this change can have is no small matter, especially when combined with a heatwave. For vulnerable members of the population, including those over the age of 65, deaths due to heat stress are much higher when night-time temperatures exceed 25 °C indoors. Of course, air conditioning can help bring room temperature down, but there may be more sustainable solutions out there. Thomas Nehls, a researcher at Technical University Berlin, Germany, suggests vertical gardens are among them. He presented his recent research at the Assembly in April.

Roof and wall structures are ideal for urban greening, but with much more wall space going, vertical gardens could well be the future. Credit: Ryan Somma

Planting building walls with greenery provides shade, reducing the solar radiation reaching the building and the way plants uptake and lose water also helps remove heat. Between a bare wall and a green one, the difference in temperature can be as much as 16 °C on a hot summer’s day and – over a large area – these vertical gardens could help cities stay cooler. “For indoor night-time heat stress, every single wall especially south, south-west and west oriented walls will reduce the heat stress inside the buildings,” explains Nehls, whose interest in urban greening started with ideas around how to handle rainwater in cities.

“Water needs to get evaporated into urban atmospheres instead of being drained to the sewers and, finally, rivers or surface waters,” asserts Nehls. Vertical gardens slow down water movement, allowing it to be used by plants, and evaporated back into the atmosphere, rather than racing down a gutter. It means the gardens can be watered sustainably too.

Ongoing research at the Department of Land, Environment and Infrastructure Engineering (DIATI) in Torino, Italy, goes one step further – exploring whether vertical gardens can clean up domestic wastewater too.

A tiny vertical garden in testing at the Department of Land, Environment and Infrastructure Engineering at Politecnico di Torino. Credit: Alice Caruso

The average person uses 200-250 litres of water per day, and most of this ends up as wastewater, which usually requires energy to treat and make reusable. But, with vertical gardens, we can do the same with much less energy and fewer resources.

The idea is simple, by covering building walls with layers of plants, you get the many benefits of urban greening, and your very own wastewater treatment facility.

How domestic wastewater purification works. Credit: Alice Caruso

The design is currently being tested on university buildings at Politecnico di Torino, and is capable of cleaning all domestic wastewater except sewage. With roughly 100 litres of this produced daily per person, the technology could be a big step towards meeting water treatment demands. Scaling up the technology is the next challenge, including working out how the vertical wall should be built to meet the needs of a family.

Domestic wastewater provides plants with the water they need and, as it percolates through the system, the water is slowly cleaned and stripped of many ‘undesirables.’ The process removes many common pathogens, present in concentrations orders of magnitude lower than the original wastewater. Microbes in the soil and roots are thought to do most of the work, but exactly how they purify the water is not yet known. Together, the plants and microorganisms remove nutrients and contaminants.

“We need energy to treat water, we need energy to make water drinkable and we need energy to pump it into houses. This kind of application is going to reduce all that,” Boano explains.

There may be other benefits too, “green surfaces in your direct surroundings will keep you calm, reduce blood pressure and other symptoms of stress,” suggests Nehls, emphasising that while the benefits to wellbeing aren’t fully known, there’s a lot of potential.

For the scientists working on the future of our cities, the reasons for making them greener couldn’t be clearer: “[we want] to make the environment more comfortable for people and our children,” says Politecnico di Torino’s Alice Caruso, who presented the work at the Assembly.

By Sara Mynott, EGU Press Assistant

Imaggeo on Mondays: The salt mine carving into the Carpathians

Imaggeo on Mondays: The salt mine carving into the Carpathians

The image gives us a glimpse into the Slănic Salt Mine in central Romania, about 100 kilometres north of the capital city Bucharest. The region was actively mined for almost 30 years, from 1943 to 1970.

The Slănic Salt Mine is the largest salt mine in Europe, and the facility consists of 14 large chambers, each more than 50 metres high. The cavities of the mine, more than 200 metres deep, carve into the Southern Carpathian Mountains, offering a unique large-scale view into how the layers of rock beneath the Earth’s surface bend and fold. The structures featured in this image were stretched out over time as the Earth’s tectonic plates shifted, highlighting just how fluid our planet can be.

Compared to other rocks, the rock salts in this mine can change form and flow without much pressure and at relatively shallow depths. “This flow is however very slow, so that man-made cavities in salt mines deform very slowly and remain open for decades,” notes Janos Urai, a professor of structural geology, tectonics and geomechanics at RWTH Aachen University in Germany who snapped this image while visiting the mine in 2017. “We study this slow flow of salt in nature, to be able to improve predictions of the long-term evolution of nuclear waste repositories and abandoned salt caverns.

The mine is no longer used for resource extraction, but is now an active tourist destination (there are even playgrounds, pool tables and other recreational features).

By Olivia Trani, EGU Communications Officer

You can learn more about salt tectonics on the Tectonics and Structural Geology blog here:  Minds over Methods: Reconstruction of salt tectonic features

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

The ReSToRE summer school on the sustainable development of Earth resources: reflecting back

The ReSToRE summer school on the sustainable development of Earth resources: reflecting back

How can we source and use Earth resources in an ethical and responsible way? And how can we bring different actors and communities together to achieve sustainable resource development? These are just some of the questions that early career researchers from around the world came together to discuss during the inaugural Researching Social Theories, Resources, and the Environment International Summer School, held at the University College Dublin last month. In this blog post, Anthea Lacchia, a postdoctoral researcher at the Irish Centre for Research in Applied Geosciences, and Jen Roberts, a Chancellor’s Fellow in Energy at the University of Strathclyde, share their experience reporting on this summer school.

On the first week of July 2019, we were lucky enough to be part of a very special gathering of geoscientists and social scientists from developed and developing countries at University College Dublin (UCD), Ireland. The occasion that brought them all together was the inaugural Researching Social Theories, Resources, and Environment (ReSToRE) International Summer School.

The goal of the ReSToRE summer school was to enable critical cross-disciplinary discussions around the sustainable sourcing and use of Earth resources now and in the future. Big topic, right? And certainly one that can only be tackled by bringing together different perspectives, as became apparent during the week.

Organised by iCRAG, the Irish Centre for Research in Applied Geosciences, the summer school included 42 early career researchers and recent graduates from 28 nations including 18 developing countries.

“Moving forward for sustainable development is very complicated,” said Murray Hitzman, Director of iCRAG. “Not only are there technical challenges in terms of Earth resources and energy, but in terms of how people actually perceive both sustainable development and those challenges is even more critical.”

“This summer school is trying to help with this not just in one society, but in multiple societies, and to get those societies to understand one another as well, which is also a huge challenge,” he noted.

The summer school succeeded in creating a stimulating setting for interdisciplinary collaboration, knowledge sharing and network-building. During the week, participants discussed emerging themes pertinent to the future of resourcing and consumption of Earth materials, such as: what drives societal attitudes toward the extraction industry? How can communities have their say in if and how resources near to them are developed? What are the barriers to a circular economy in the resources sector? How can Earth materials be resources in an ethical and responsible way?

Participants took the lead in deliberating these big questions. They were aided by guidance from expert mentors, as well as plenary talks and discussions. The conversations naturally spilled from the workshops into the social events, which included a fieldtrip to Glendalough, Co. Wicklow, Ireland, the site of an ancient lead, zinc and silver mine, and now a spectacular glacial valley.

And Summer put on a fine performance for the week, allowing the participants to move outside and seek inspiration amongst the fresh air, daisies and curious ducks.

ReSToRE painting by summer school participant and artist, Meenakshi Poti (joint PhD student at Université Libre de Bruxelles and Vrije Universiteit Brussel, Belgium).

“Deposits of the metals that we need are irregularly distributed across the globe, and their value must be assessed with respect to sustainable development, alleviation of poverty and empowering of communities,” said International Union of Geological Sciences (IUGS) Councillor, Edmund Nickless, at the opening session of the summer school.

“This course is asking the right questions at the right time and the mix of social scientists and geoscientists and environmental scientists together is a triangle we really need,” added Ozlem Adiyaman Lopes from UNESCO’s Earth and Ecological Sciences division, who was able to join the summer school for several days.

Amongst participants and expert mentors 33 different nationalities were represented, including from Afghanistan, Australia, Bangladesh, Belgium, Botswana, Canada, Chile, Colombia, Congo (DR), Croatia, Ethiopia, Finland, Germany, Hungary, India, Ireland, Italy, Kenya, Lithuania, Mozambique, Namibia, Netherlands, Papua New Guinea, Russia, Sierra Leone, South Africa, Sweden, Switzerland, Tanzania, Turkey, UK, USA, and Zimbabwe. What an incredible forum!

Some reflections on the way ahead

Some key themes emerged from the conversations amongst the participants, expert mentors and organisers during the week. Firstly, the different actors necessary for resourcing a sustainable future cannot be considered in isolation. Consumer demand, business practices, environmental and societal impacts, community involvement in decision-making and development are all intrinsically interlinked in a non-linear chain which interweaves resource supply use and reuse.

Future resource development in line with global sustainability goals will require interplay between the technical and non-technical worlds, bridging policy, industry, practitioners and academia, and uniting geoscience and engineering, and social and political science, as well as local communities.

Summer school participants admiring the Irish landscape during the ReSToRE fieldtrip, Sally Gap, Co. Wicklow.

The circular economy, which aims to extract the most value out of resources and materials whilst in use, can act as a useful model for the resource sector: wherever one is placed along the supply chain from producer to consumer, we should all be supporting ways of producing resources cleanly and efficiently, with reduced, managed and – where possible – reused waste. And the management of mining waste has had increased profile in the past few years, with several tragic and preventable collapses of tailings dams which have had major societal and environmental consequences.

Our role

As reporters of the ReSToRE summer school, our role was to take note of the event and support the delivery of key outcomes. This meant that we were very busy capturing thoughts from participants, organisers, speakers and mentors through interviews, soaking in the atmosphere at the various social events and workshops, and carving out occasional moments to sit down by the lake at UCD and reflect on the week and how it was going. We relied on a trusted voice recorder and notebook, and quickly became acutely acquainted with the opening hours of cafés around campus. The participants’ WhatsApp group also proved incredibly useful for gaging how participants were feeling, as well as asking people to gather round for a photo, check a nationality or give advice on the best sights in Dublin, or pubs showing the Women’s World Cup.

More importantly, the summer school provided opportunity to create a diverse, international network of like-minded individuals working in the interdisciplinary sphere, as well as enabling everyone involved, including participants, mentors, organisers and ourselves to learn, reflect, and to create potential new avenues for research and collaboration.

One of the highlights has to be the mix of nationalities and cultures represented, as well as a general spirit of openness to new ideas and perspectives. Although the week was intense and the workshop participants were tasked with preparing presentations of their findings for the final day, the support and lack of competition amongst participants was palpable, and paved the way for creativity to emerge. Together, they created a safe space in which to be open, reflective, responsive and curious, and to bravely tackle some very complex questions.

We hope to continue these conversations at the interface of societal issues and geoscience at future conferences, such as the EGU General Assembly 2020. We hope you are inspired to join in. See you there!

By Anthea Lacchia (Irish Centre for Research in Applied Geosciences at University College Dublin) and Jen Roberts (University of Strathclyde)

Find out more

A suite of summer school resources, including live-streamed videos of the presentations and discussions by experts in the field and blogs from the delegates, can be found on the ReSTORE webpage: https://www.icrag-centre.org/restore/

iCRAG, the International Union of Geological Sciences and Geological Survey Ireland were the organising sponsors of ReSToRE, which was run under the patronage of UNESCO.

Sponsorship also came from BHP, Boliden, Rio Tinto, Teck, with additional support received from Irish Research Council and UCD College of Business.

About the authors

Anthea Lacchia

Anthea grew up in northern Italy, in a town at the foot of the Alps. Having studied Classics in high school in Italy, she moved to Ireland and obtained a BA in Geology from Trinity College Dublin.  During her undergraduate studies, she developed a keen interest in thinking about the lives of ancient animals preserved in rocks – fossils – which led her to pursue a PhD in palaeontology, specifically looking at extinct relatives of squid and cuttlefish called ammonoids. She spent many seasons of fieldwork perusing the rocks of Co. Clare, in western Ireland. In parallel with her research, she gained experience both in science writing and newspaper editing. Following completion of her PhD, she spent a year working as a press officer for Springer Nature in London. She then returned to Ireland to start postdoctoral research in iCRAG, the Irish Centre for Research in Applied Geosciences, in University College Dublin, where she is studying public perception and understanding of geosciences, with a focus on the geology and communities of Co. Clare. Her postdoc allows her to combine her passion for geology with that for science communication and public engagement. Anthea also works as a freelance science writer. Anthea took part in the ReSToRE Summer School as a reporter.

Jen Roberts

Jen is a Chancellor’s Fellow in Energy at the University of Strathclyde. Her research is interdisciplinary and applied, and addresses the social and environmental risk of geological resources – often relating to energy. Jen uses her technical background in geology to tackle questions relevant across geoscience, environmental science, environmental psychology, environmental engineering and political science. These questions relate to the perception, assessment and communication of risks relating to low-carbon energy technologies, which, for many, the subsurface plays a vital role. Ultimately her work aims to inform how the necessary transition to a net zero carbon future can be implemented in a way that is acceptable to society and to the environment. Jen took part in the ReSToRE Summer School as a reporter.