Grey Britain: Misery, urbanism & neuroaesthetics

View of London from the Sky Garden (source:
“We have created a Star Wars civilization, with Stone Age emotions. We thrash about and are a danger to ourselves and the rest of life.” – E.O. Wilson, The Social Conquest of the Earth (2012).


In a previous article I have discussed the use of simple patterns to interpret the complexity of nature and the human interface with it. Here, I will illustrate this concept on a larger canvas, discussing this interface, between nature and social systems, more thoroughly. This final article, in the series on inter-disciplinary work I have written for the University of Bristol Cabot Institute for the Environment, is partially motivated by my personal interest in the cycle of urbanism, the associated architecture and concepts. It is also motivated by a project I followed closely during a past flirtation with living and working in London and the comparable changes I see happening around me in Bristol, where I currently live and work.
Billboard #1 from London is Changing project (source:

‘London is Changing’ was an arts project undertaken by Dr. Rebecca Ross at Central St. Martins in 2015. It highlighted the effects of economic policy in the capital by displaying the stories of individuals relocating in, out and within the capital, out of choice and necessity, on billboards around the city. On one level, this project introduced me to the plight of individuals whose movements are determined by expropriation, economic policy or various other processes largely beyond their control. On another level, it gave me an insight into the emotional response this change in environment can invoke in those undertaking such change.

Indeed, as modern society has ridden the wave of an economy of concentrated wealth creation the transient notion of moving somewhere new for education or employment has become a perceived norm. Yet, there is a polarising undercurrent to this wave, in which generations of individuals face the prospect of never being able to afford to permanently root themselves to the environment, where the terms ‘gentrification’ and ‘displacement’ have come to define the nature of settlement and where our demand, and in some cases, expectation, of a ‘home’ is placing an unsustainable strain on ourselves, materials, space and the environment at large. Be it due to social, economic or environmental causes, these trends are effectively driving people further from their familiar habitat and immediate social connections, which leads to social destabilisation – a key contributing factor of societal vulnerability.

Billboard #2 from London is Changing project (source:
The inter-environmental patterns of displacement and resettlement are as intriguing as they are worrying. Similarly, a concept related to this physical displacement, the notion of intra-environmental displacement is one which can set the foundations of an unstable social system. This is to say, an emotional displacement characterised by a detachment created through rapid physical change of the surrounding environment, one that can enhance the disconnection between people and their environment and, in some cases; other people. Notionally linked to gentrification, urban renewal or regeneration is part of the cycle of urbanisation and whilst it does not immediately or physically displace a person from the environment, it’s effects are becoming more documented and this is to a largely negative fanfare.
Drawing on the personal experience of having worked and socialised with residents of the recently regenerated Heygate, Aylesbury, the (old) south Kilburn Estates in London and coupling this with my academic work and interest, I have given great consideration to the phenomena of intra-environmental connection and disconnection. Indeed, the initial results of my own research with flooding and social systems is conspecific with the kind of systematic social change discussed in this article, differing only in temporal scale, whereby enhanced social interaction has the potential to negate the detrimental effects of uninvited change, be it rapid onset as is the case with a flood inundation or prolonged onset via environmental redevelopment, to the structure of the social system. Observing the changes currently taking place in Bristol, at Temple Quarter and along the southern bank of the Avon, I feel urgency in the need to communicate the detrimental potential of poor foresight, as well as the positive potential of implementing new approaches, in urban development and renewal of any kind.

The Biophilic Hypothesis, P2P Urbanism & Neuroasthetics

Biophilia is a term that was first introduced by psychoanalyst Erich Fromm in 1973’s ‘The anatomy of human destructiveness’ to describe a “passionate love of life and all that is alive”. One only needs to pause for a moment to consider this term in relation to current global affairs to concur with the author in his estimation that it is distinctly lacking from the zeitgeist of our time.
Biologist and foremost proponent of sociobiology, E.O. Wilson later utilised the term to describe “the urge to affiliate with other forms of life”. Wilson has suggested that this urge, to affiliate and connect with one another, other species and the natural environment at large is a biological necessity in the continuation of our species. Furthermore, Wilson has also suggested that a true or complete biophilic environment would be one that provides an appropriate habitat and home whilst also naturally connecting the human to the environment via the promotion of natural social and environmental connections. The biophilic principle has acted as the inspiration and catalyst for a divergence in thinking related to modern urban theory.

The structure of life I have described in buildings is deeply and inextricably connected with the human person and with the innermost nature of human feeling

 – Christopher Alexander, Nature of Order (1963).
Nikos Salingaros and Christopher Alexander, leading design theorists, polymaths and ardent critics of modern architectural design, have suggested in their works that a historic shift in urban architectural design accompanying post-world war II urbanisation, based on a supposed ideal concept of order over function or form, has become a pseudo-standard leading to a widespread loss of environmental identity at the human scale within the built environment initially through sprawl and latterly grand-scale, monoculture.
This loss of identity occurs through a number of routes, aesthetically via design or use of distally sourced materials, unclear structural purpose via desired use of the structure superseding local need or location via dramatic replacement of a visually recognisable building of historic or social importance. Salingaros and Alexander have suggested that this loss of identity lends itself to a loss of societal orientation and has partially or fully led to the proliferation of all things from social polarisation to the increasing rates of mental ill health in urbanised areas.
Drawing influence from Wilson’s concept of concilience, Salingaros has proposed many alternative solutions for the reconciliation of urban development at the human scale, solutions which are based on rigour with a view to addressing future human needs and ambitions. One of the most ambitious and rigorous of these solutions is P2P Urbanism.
P2P Urbanism is a process of open-source urban intervention carried out cooperatively across a spectrum of people and agencies with vested interest in the evolution of their urban environment, not just architects and city planners. It is primarily based on the application of analogous techniques of file sharing and open-source software with design patterns generated by Christopher Alexander. The idea underpinning P2P being that it is a reflection of the human elements available for input and so, theoretically, will reflect the very needs and ambitions of those engaging with the process. Thus, with greater engagement, across a broad spectrum of human groups and agencies, P2P can potentially address the need for reconnection of the urban environment at a human scale whilst offering progressive alternatives to urban sprawl and monoculture through Alexander’s designs; a potentially true reflection of us in the environment within which we reside. With Bristol’s burgeoning IT-centric industry, the potential a concept like P2P has to illicit a desirable trend of urbanisation, one which fosters a reconnection between people and place, is great.
Jinu Kitchely states, in her 2015 article on Fractals in Architecture, that “architecture as an art form enjoys the privilege of spatiality in addressing human perception and sense.” A complete biophilic environment would be one which fully addresses human perception and sense, “architects who have responded to this instinctive need, by going beyond structural constraints and catered to the emotional needs of the user, have historically achieved much more than the creation of mere shelters.” An obvious source of inspiration for the biophilic environment is nature, with many architects and designers “probing vehemently into the nature of natural forms and organisms to identify and understand the great concepts of the master designer.”
A key concept of the biophilic principle, as applied to architectural design, is the incorporation of nature’s morphology iteratively in the urban re-shaping process. I have previously spoken about how complexity arises from fractal systems, the basic quality of fractal geometry being that it is iteratively-defined – it must be described in terms of steps involving the result of previous steps. Over infinity, fractal generation is recursive and so, in theory is infinitely complex. Benoit Mandelbrot stated in his seminal book ‘The Fractal Geometry of Nature’ that the physical manifestation of this theory, of objects substituting themselves for copies of themselves, can be seen all around us and is the basic process that underpins all living things. Christopher Alexander’s analogue for this is that of a bone’s form which, evenly distributes structural stress across its surface, emerges as a result of a biological program telling cells to add bone mass where stress is likely to be greatest and so is an example of physical and structural feedback shaping the object.
Analysis from Richard Taylor’s research suggests that eye patterns traced from observations of Jackson Pollock’s paintings (left) elicit a significant physiological response in the posterior of the human brain that reduces stress through pattern recognition (right) (source:
Professor of Physics, Psychology and Art at the University of Oregon, Richard Taylor has created an interdisciplinary team that investigates the physiological response of humans when they observe these fractal patterns. Termed fractal expressionism, using work produced by Pollock and Escher, Taylor’s team has found that the format in which people examine these patterns can elicit a positive physiological response, one which reduces stress as the fractal structure of the human visual cortex resonates with the fractal image identified. From the discovery of fire by early humans to the evolution of contemporary artistic concepts, neural and physiological sense and response to natural, iterative patterns of the world around us has been influential in directing the evolution of the human brain and its emotive response system. From this understanding, it seems logical to assume that the structures we build in the environment around us possess the potential to have an impact on this system too.

Connection & disconnection



Images of the Heygate Estate, Elephant and Castle, London taken in 2014 pre-demolition, post-expropriation. (source: top middle by Tom O’Shea. Bottom:
Now, as this colloquy reaches a coda it feels important to illustrate some examples of successes and failures in respect of that which is written above. The images directly above, taken of the Heygate Estate in London once all residents had been removed from the large estate complex; some forcibly others under enforced willingness – as their lifelong homes were subject to a compulsory re-purchase at 40% of their actual value. The images depict discontent and anger, indeed more damning than the enormous displacement of a strong community under duress, is that the majority of flats and houses built on the land of the Heygate have been sold to overseas investors for a price vastly above what the old flats were purchased for. It is clear that this style of urbanisation is one which fosters a disconnection between people and place.
The iconic Trellick Tower, Westbourne Park, London. Considered an eyesore in its early days and symbol of failure for the utopian architectural ideals of the ‘streets in the sky’ movement of the 60’s. The brutalist structure is now credited as a glowing success of how distinct architectural style can connect a community (source:
Just one and a half miles away from the Heygate is Trellick tower. Ernö Goldfinger’s brutalist 70’s masterpiece, designed as a positive response to the ‘architecture of doom’ employed by the Nazi’s during WWII. The tower employed biophilic facets of utilitarian materials and purpose to create an iconic aesthetic that emphasised robust and reliable living spaces for residents with community as a centrepiece. In the years since its completion, the tower has had a fair share of criticism but has since emerged as an iconic element of the London skyline, an aesthetic centre-point of the city’s urban fabric and one which is now seen as a triumph of biophilic ideals. Much like Corbusier’s Chandigarh and Bofil’s La Murilla Roja, Trellick made the needs of the human scale a priority, with form and function evolving from there. Chandigarh is consistently seen as the standard of how biophilic ideals can be applied to planned cities, Corbusier’s design for the city was based on the human body, and Bofil’s La Murilla, a community housing project in Alicante, looked to connect the residents with the cliffs into which it was built and the sea below, whilst providing a stimulating and iconic aesthetic to foster the sense of a unique community.
Images of La Murilla Roja (top) and The Palace of Assembly, Chandigarh (bottom) (source: Wikipedia).
These iconic buildings and cities contain unique community characteristics, and this is because they incorporate a consideration for just that. As British cities expand to cope with demand and greenfield sites are increasingly developed to provide affordable housing, the concepts discussed above, and examples highlighted throughout, must be considered with a view to sustainable progress. Trellick tower, Chandigarh and the like provide an iconic representation of a time and a place in our relationship with the built and natural environments, they can provide inspiration for what is possible.
Concepts like Salingaros’ P2P urbanism offer an inclusive approach for the future development of cities, currently or due to be, undergoing great change; like Bristol. Ultimately, systematic social vulnerability is a complex convolvulus of interactions on a vast spectrum of scales, addressing it should be a priority and opening the avenues of investigation outlined above is one way to begin.
Sir Denys Lasdun, said of the architect’s job as being “Not to give a client not what he wants but what he never dreamed that he wanted; and when he gets it, he recognises it as something he wanted all the time.” By considering how to connect us with our urban environments more, through the conduit of nature and the biophilic, the author believes that the process of urbanisation can afford us with a sense of place far beyond our dreams and more importantly, one which we should have had all the time. Failing this, follow the advice of the billboard below and enjoy the gifts of nature before they are consumed by the belligerent grey beast of indifferent urbanisation.
Billboard #3 from London is Changing project (source:


This blog was written by Cabot Institute member, Thomas O’Shea, a Ph.D. Researcher at the School of Geographical Sciences, University of Bristol. His interests span Complex Systems, Hydrodynamics, Risk and Resilience and Machine Learning.  Please direct any desired correspondence regarding the above to his university email at:
Thomas O’Shea
Read Thomas’ other blogs in this series:

Bristol Future’s magical places: Sustainability through the eyes of the community

Silba Island. Credit Wikimedia Commons.

“What is science? Why do we do it?”. I ask these questions to my students a lot, in fact, I spend a lot of time asking myself the same thing.

And of course, as much as philosophy of science has thankfully graced us with a lot of scholars, academics and researchers who have discussed, and even provided answers to these questions, sometimes, when you are buried under piles of papers, staring at your screen for hours and hours on end, it doesn’t feel very science-y, does it?

As a child I always imagined the scientist constantly surrounded by super cool things like the towers around Nicola Tesla, or Cousteau being surrounded by all those underwater wonders. Reality though, as it often does, may significantly differ from your early life expectations. I should have guessed that Ts and Cs would apply… Because there is nothing magnificent about looking for that one bug in your code that made your entire run plot the earth inside out and upside down, at least not for me.

I know for myself, I spend the biggest part of my day looking at my screen, tilting my head slightly to the right like a puppy and trying to make sense of my figures and results. There are days, the really bad days, where I just ask myself out loud “what is this even?!” or “why am I even doing this?”. Screen never answers by the way; for future reference.

And then, there are other days.

As Bristol Futures has now entered its optional unit development phase, the Sustainable Futures team and myself, had the opportunity to visit an amazing island in Croatia. The island of Silba. The purpose of our visit there was to film three Non-Governmental Organisations (NGOs) that are working on launching an amazing initiative: project S.I.L.B.A (Sustainability Increases Life Benefits for All). This project is targeting several Sustainable Development Goals (SDGs) such as ‘Ethical Consumption and Production’, ‘Life Under Water’, ‘Life on Land’. The goal of the project is to create a waste free, carbon neutral island.

Our amazing cameraman Tim Osgood and myself arrived there thinking we were going to film the three founders of the three NGOs and be on our way. Little did we know about the amazing innovations and initiatives that were already well in place on the island of Silba. So, we decided to film several of the locals as well.

I don’t know what I expected to hear when I asked the locals if they knew ‘what sustainability and sustainable development was’. I guess I just was not prepared for someone like Mio.
Mio used to work in large ships, he used to work the radio. Of course, as technology developed his work wasn’t needed anymore, so he decided to go back to Silba and become a shepherd. For twenty years he has been raising goats and sheep, makes cheese (even vegan cheese from figs!) and sells it all over the world. He also makes and sells honey and olive oil; “sometimes” as he said, when the olive trees have behaved.

We are about to begin the interview; he explains to me that he hasn’t had any alcohol for the last 20 years, but he must smoke.

“Do you know what sustainable development is?”. That was my first question. In retrospect it was probably a very uninformed question.

Mio went away and brought me this very elaborate piece of metal and asked me if I knew what it was. Of course, I didn’t. He explained to me it was a device that helped him stabilize his saw while he would cut the very dry olive tree wood that he needed. All the materials he used for it he had found thrown away in different parts of the island, “this is what sustainable development is” he said.
Quite frankly, I was shocked; and a bit embarrassed.

I come from the Balkans myself. I’ve only lived in the UK and been in academia for 3 years! So how did I forget that of course the communities know what sustainable is? Of course the locals are very aware of all things sustainable, perhaps even more so than someone like myself that now deals these issues from a more theoretical point of view?

It’s funny, well not haha funny, but it is genuinely interesting how once you start dealing with a subject, an issue, a challenge theoretically, how fast and how subtly you can lose contact with what is actually happening out there.

And even the word ‘sustainability’, with all its complexity and definitions (oh the definitions), frameworks and literature, goals and targets, had perhaps slightly lost its meaning until Mio picked up that pile of metals and showed it to me. That’s what it was. Right there. Tangible if slightly scruffy looking.

He either read my face or my mind, so he started talking again and saved me from my own thoughts.
He explained to me the big issues the community of the island is dealing with; water shortage, growing numbers of tourists every year, infrastructure and land use.

“Do you think science can help you? Help this island?” I asked him.

And Mio held my hand and explained to me that what he wants from science, and scientists is to help him solve his problems, his real, everyday problems, and then he can solve the problems of his island; “we can do this, we can clean the island, we dealt with worst issues than plastics on our beaches, but first, first we need water all year round”.

So there you have it; that 70 year old shepherd had just defined both sustainability and science. Right there, in a 20-minute interview.

I came back to the UK feeling better. Better about the piles of papers, the effort, the staring at my screen, the bugs in my code and my screen not answering back; it all didn’t seem like such a big problem anymore.

Because that’s it, that’s what we do. We help Mio, help his island. And there is no better feeling than that.

And I guess this is why I am so very much in love with Bristol Futures at the University of Bristol, for giving us the opportunity to explore those issues, those communities, and ourselves.

This blog is written by Cabot Institute member Eleni Michalopoulou, a Doctor of Philosophy student in the School of Chemistry at the University of Bristol.
Eleni Michalopoulou

What makes cities more environmentally sustainable: A comparative study of York and Bristol

Over the summer of 2017 I conducted 25 interviews with policymakers and key stakeholders – 17 in York and 8 in Bristol. The interviews involved wide ranging discussions on the three pillars of sustainability – environment, social and economic – in the city of the interviewee.

Some background to the study and why I chose Bristol to compare with York – coming from the Leeds/Bradford conurbation, York seems like such a pleasant place to me: incredible preservation of its heritage, affluent, with very few of the economic and social problems experienced in some other parts of Yorkshire. However, having lived in York for a couple of years, I’ve realised when you scratch the surface a little, it’s not perfect. There are quite interesting dynamics in the city that prevent it from achieving its potential, particularly environmentally…

Enter Bristol as a comparison city!

Having won the European Green Capital 2015, Bristol was an obvious choice. Although initially my concern was there are stark differences between York and Bristol in terms of size, culture etc., it soon became apparent that these differences only highlighted the dynamics within each city that I was trying to uncover.

My research found that York’s two largest challenges in trying to be a more environmentally sustainable city are its political flux – due to finely balanced politics based on geographic location within the city – and heritage. Because of the flux, there is a lack of long-term vision for the city in addition to large political risks to parties that seek to enact less salient environmentally sustainable policies. When the flux is combined with the city’s conservatism – due to a culture of preservation – York can lack ambition.

Furthermore, York lacks economic sustainability, which is due to several reasons: the relatively recent loss of many of its large anchor employers, such as Rowntree’s, Terry’s and the Carriage-works; a focus on the low value-added tourist industry; high-office costs; high-living costs for employees; and a difficulty in accessing government infrastructure funding due to being on the edge of two Local Enterprise Partnerships. Additionally, whilst York has many small to medium sized enterprises – who reinvest a higher portion of their income into the local economy than large companies – it lacks the alternative business models, such as those found in Bristol, that can bring wider benefits. Therefore, due to economic unsustainability and a lack of alternative business models, the city’s business focus is on job growth as opposed to wider societal and environmental benefits, such as was found in the business focus of Bristol. Many of the positives that York possesses are due to the natural advantages that result from its built environment. The lack of ambition and vision, however, is preventing York from achieving its full potential. Being a city rich in heritage does not mean that it cannot also have a strong environmental sustainability focus, as discussed by Paul McCabe, Strategic Manager – Sustainability and Transformation, City of York Council:

“Other cities around Europe have shown that the two things are not incompatible: old architecture, green architecture, big public spaces, bold things can work together and compliment older areas.”

Bristol is an example of what a city can achieve in terms of environmental sustainability in a country with a very centralized state whose policies at a national level may be perceived by some as regressive. Additionally, while Bristol does have social problems, many of these may be inherent in large British cities. Bristol’s pursuit of green capital can be seen as a means to identify itself on a wider stage for pride and to attract inward investment – In this context I am using the term ‘capital’ to express the assets that a city has available to itself. In this sense green capital is not only a physical asset of entities such as green spaces for instance, but an asset embedded in urban cultures that has wider consequences – Why Bristol is pursuing green capital may be due to seeing the makings of this within its own culture: Bristol has a notably vibrant culture that is hard to define and account for, but appears to be bringing many social, environmental and economic benefits to the city. This vibrant culture was commented upon by James Cleeton, Sustrans England Director South, “what Bristol does well, is what its people do: there’s still that culture, that socio-cultural drive behind a desire for a really sustainable and green city”. Furthermore, the pursuit of green capital may only be possible in the city due to a long-term vision that emerges from political stability, the importance of which is contrasted with York’s changing administrations and relative lack of political stability. Although Bristol stands to benefit economically from green capital, this pursuit of green capital is perhaps only enabled because Bristol is already economically successful.

Therefore, I found what makes cities more environmentally sustainable revolved around the interaction between four themes: culture, economics, politics and social. These four themes all, in varying forms, influence environmental sustainability in a very individual nature within each city. Perhaps the most important influence, however, was found to be the status and nature of the capital that each city possessed – be that the heritage capital that holds York back, or the green capital that pushes Bristol forward, in this regard.

To read the full study, please see two versions: a shortened version and the full version.

This blog was reposted with kind permission from Bristol Green Capital PartnershipView the original blog.

This blog was written by Graham Gill from University of York.  Graham can be contacted by email.

Graham Gill

The muddy debate: Is the Severn Estuary biologically productive?

Severn Bridge by Philippa Long

Traditionally, the Severn Estuary has been mistaken for an expansive, featureless landscape, dominated by fast-flowing muddy waters that prevent any pelagic biological activity. Although the latter could be true in terms of phytoplankton development, new research has shed light on the vital role that the benthic algal system has on controlling nutrient dynamics in the estuary.

Estuaries form at the margins between the land and the sea. The complex movement and mixing of freshwater and seawater governed by the tide, along with the trapping and recycling of continentally supplied nutrients and sediment, makes estuaries some of the most ecologically viable ecosystems in the world, in line with the biological productivity of coral reefs and tropical rainforests.

The Severn, the largest of 133 estuaries in the UK, has a mosaic distribution of intertidal mudflats, saltmarshes and wetlands, making it a unique habitat for a wide range of species. Alongside nationally scarce plant species, important wildfowl, wader populations and migratory European birds inhabit and refuel in the biologically-rich banks of the estuary. The estuarine waters are also home to over 100 fish species that use the estuary as a nursery, supporting many of the UK’s commercial fish stocks. With such a wide socio-ecological and economic importance, it is clear why the Severn was designated a Special Area of Conservation in 2009.

However, it’s less obvious as to why it has been over two decades since there have been systematic sampling studies in the Severn. Reviews have come and gone during this time, widely associated with renewable energy projects such as the Severn Barrage, but have often repeated findings from the 1990s. Furthermore, any commercially driven studies and their findings are often not disclosed to researchers or the public. This has left, in many aspects, knowledge of the Severn and its current ecosystem condition in a state of limbo. One aspect that’s often overlooked in many hydrological systems and is often overshadowed by carbon, nitrogen and phosphorus, is the element silicon, which may be one of the most important nutrients in the Severn’s environment.

Sand Bay by Holly Welsby

Why is silicon important?

Dissolved silicon is an important nutrient in aquatic environments, and is essential to siliceous organisms, for example, photosynthetic diatoms, which use dissolved silicon to form their shells (or frustules) made from biogenic silica. Diatoms are broadly categorised as ‘centric’ (round), usually occupying the surface oceans, and ‘pennate’ (long and thin), inhabiting coastal and seafloor environments, including sea ice, and intertidal mudflats such as those in the Severn Estuary.

Despite their small size, diatoms are an important group in supporting most food webs, and due to their abundance, contribute close to half of all surface ocean productivity! Diatoms are a key factor in affecting climate change due to this high productivity, as they remove the greenhouse gas carbon dioxide out of the atmosphere and export the organic carbon from the surface ocean to the seafloor when they die. Dissolved silicon and biogenic silica have been widely used to study marine silicon cycles but the impact that diatoms may have on estuarine cycles, and the potential influence on river silicon inputs to the ocean, has only recently come to light.

Silicon cycling in the Severn Estuary: new research

After the receding of the tide, large intertidal mudflats form along the shores of the Severn Estuary, which has the second largest tidal range in the world! These nutrient-rich intertidal mudflats are inhabited by pennate diatoms that live in microbial mats, called biofilms, on the mudflat surface. These biofilms, which are visible to the naked eye (the golden-brown shimmer that can be observed on the mudflats at low tide), are low in biodiversity but high in diatom abundance. Biofilms are an important food source to many mud-dwelling creatures, such as estuarine ragworm and laver spire snails, and migratory visitors such as the whimbrel and ringed plover. These ‘sticky’ mats also contribute to sediment stabilization, through the production of an organic rich network around sediment grains, and control nutrient fluxes to the overlying water.

Biofilm on the intertidal mudflats of the Severn by Holly Welsby

Compared to the well-studied carbon, nitrogen and phosphorus cycles, the importance of silicon in the Severn Estuary is less well understood. New research that has been carried out at the University of Bristol has aimed to tackle this gap, with an in-depth, seasonal study of silicon cycling along the Severn river-estuary-marine continuum. Each season in 2016, the surface and bottom waters of the Severn were sampled aboard Cardiff University’s research vessel.

It was found that the strong tidal forces and seasonal river flow fluctuations controlled dissolved silicon and other associated nutrients. In line with previous studies, the high mud water content – referred to as turbidity – limited water column primary productivity by blocking out light. This meant that there was minimal biogenic silica production in the water column itself. Instead, biogenic silica depended on the suspended particulate matter, and displayed seasonal cycles associated with benthic biogenic silica production by the diatom biofilms on the mudflats. In other words, the suspended sediment in the Severn not only originated from the rivers discharging into the estuary, but also from the erosion of the intertidal mudflats. This erosion of the mudflats in this high energy system, led to the suspension of the diatom biofilms, and so increased the biogenic silica concentrations in the water column.

This research has shown that since the 1990s reports, diatom biofilm biomass (i.e. their presence) has increased on the mudflats. These diatoms were also efficient at photosynthesis, resulting in a high potential to cycle silicon. These biofilms break up and reform rapidly between tides meaning that a large amount of silica is shuttled from the mudflats to the water column every day. This benthic biogenic silica export, which is transported further compared to dissolved silicon, could dissolve and replenish the Celtic Sea, with the dissolved silicon ready to be used by plankton that supports our commercial fish stocks.

Severn River in winter by Tim Gregory

Looking ahead

The Severn Estuary – in all its natural wonders – is a valuable resource in terms of renewable energy, tourism and business. Many of us also call it home. But what does the future hold for these diatom biofilms on the mudflats of the Severn Estuary? In many ways, their prospects are low. With extreme weather events, erosion and coastal squeezing causing a loss to our mudflat and saltmarsh habitats, influx of microplastics and associated toxins, alongside proposals for large construction projects that may alter sediment/nutrient loadings and deposition patterns, the future of these biofilms hangs is in the balance. But based on recent findings, these diatoms are tolerant to the mudflats harsh environmental conditions, which suggests they have the capability to adapt to these adverse conditions. Diatoms are a miraculous species, and their benefits to the estuary is not fully recognised.

We are beginning to understand that there is a limit to the degree that we can modify our environment, but if we could only assign an economic value to this biologically productive system, perhaps the benthic diatoms future on the Severn Estuary mudflats could be aided.

This blog has been written by Cabot Institute member Holly Welsby, from the School of Earth Sciences at the University of Bristol.

Coconuts and climate change

Before pursuing an MSc in Climate Change Science and Policy at the University of Bristol, I completed my undergraduate studies in Environmental Science at the University of Colombo, Sri Lanka. During my final year I carried out a research project that explored the impact of extreme weather events on coconut productivity across the three climatic zones of Sri Lanka. A few months ago, I managed to get a paper published and I thought it would be a good idea to share my findings on this platform.

Climate change and crop productivity

There has been a growing concern about the impact of extreme weather events on crop production across the globe, Sri Lanka being no exception. Coconut is becoming a rare commodity in the country, due to several reasons including the changing climate. The price hike in coconuts over the last few years is a good indication of how climate change is affecting coconut productivity across the country. Most coconut trees are no longer bearing fruits and those that do, have nuts which are relatively very small in size.

Coconut production in Sri Lanka

Sri Lanka is among the top 5 largest producers of coconut, alongside Indonesia, Philippines, India and Brazil (FAOSTAT, 2014). Coconut is one of the major plantation crops in Sri Lanka and is second only to rice in providing nutrition (Samita & Lanka, 2000). Coconut cultivation represents 1/5th of the agricultural land of the country and significantly contributes to Sri Lanka’s Gross Domestic Product, export earnings and employment (Fernando et al., 2007).

Mature coconuts develop approximately eleven months after inflorescence opening (Figure 1). Of this, the first three months after inflorescence opening is said to be the most critical period as the young nuts are susceptible to climatic variation (Ranasinghe et al., 2015).

Figure 1: Development stages of a coconut bunch (Source: Coconut Research Institute, Sri Lanka)

The coconut yield is influenced by climatic variables such as rainfall, temperature and relative humidity in addition to other external factors such as pest attacks, diseases, crop management, land suitability and nutrient availability (Peiris et al., 2008). Optimum weather conditions for the growth of coconut include a well distributed annual rainfall of about 1500 mm, a mean air temperature of 27°C and relative humidity of about 80-90% (Peiris et al., 1995).

Impact of extreme weather on coconut productivity

Our study analysed the impact of extreme weather events considering daily temperature and rainfall over a 21-year period (between 1995 and 2015) at selected coconut estates in the wet, dry and intermediate zones of Sri Lanka. The study revealed drought conditions during the first four months after inflorescence opening, had a negative impact on the coconut harvest in the dry and intermediate zones (as revealed by the statistical analyses and the model relationships developed in this study). Possible reasons for this include reduced pollen production due to the exposure of male flowers to elevated temperature (Burke, Velten, & Oliver, 2004) and flower and fruit abortions caused by high temperatures and absence of rainfall over an extended period of time (Nainanayake et al., 2008).

Drought conditions not only disrupt the physiological functions of the coconut palm, but also
contribute to incidences of pest attacks. At present, the Coconut Black Beetle and the Coconut Red
Weevil pose the greatest threat to coconut plantations in Sri Lanka. Drought conditions are very
conducive for Coconut Black Beetles to pupate deep in the soil (Nirula, 1955).

Implications of the findings

This study reinforces the importance of raising awareness on the implications of climate change on crop productivity. During my visits to the coconut plantations, the superintendents of the estates as well as the labourers appeared to be aware of the warming trend of the climate. They had adopted soil moisture conservation methods such as mulching, burying coconut husks and growing cover crops to prevent extreme evapotranspiration. These are short term solutions. If we are to think about sustaining the coconut cultivation in the long-term, it is important to focus our efforts on developing drought tolerant hybrids. Global climate is projected to change continuously due to various natural and anthropogenic reasons. Policy makers and market decision makers can utilize the knowledge on how coconuts respond to drought conditions to formulate better policies and prices. This information can enable us to be better prepared and minimize loss and damage caused by a drought resulting from climate change.


Burke, J. J., Velten, J., & Oliver, M. J. (2004). In vitro analysis of cotton pollen germination. Agronomy Journal, 96(2), 359–368.

FAOSTAT. (2014). Retrieved January 7, 2017, from

Fernando, M. T. N., Zubair, L., Peiris, T. S. G., Ranasinghe, C. S., & Ratnasiri, J. (2007). Economic Value of Climate Variability Impacts on Coconut Production in Sri Lanka.

Nainanayake, A., Ranasinghe, C. S., & Tennakoon, N. A. (2008). Effects of drip irrigation on canopy and soil temperature, leaf gas exchange, flowering and nut setting of mature coconut (Cocos nucifera L.). Journal of the National Science Foundation of Sri Lanka, 36(1), 33–40.

Nirula, K. K. (1955). Investigations on the pests of coconut palm. Part II Oryctes rhinoceros L. Indian Coconut Journal, 8(4), 30–79.

Peiris, T. S. G., Hansen, J. W., & Zubair, L. (2008). Use of seasonal climate information to predict coconut
production in Sri Lanka. International Journal of Climatology, 28, 103–110.

Peiris, T. S. G., Thattil, R. O., & Mahindapala, R. (1995). An analysis of the effect of climate and weather on coconut (Cocos nucifera). Journal of Experimental Agriculture, 31, 451–460.

Ranasinghe, C. S., Silva, L. R. S., & Premasiri, R. D. N. (2015). Major determinants of fruit set and yield fluctuation in coconut (Cocos nucifera L .). Journal of National Science Foundation of Sri Lanka, 43(3), 253–264.

Samita, S., & Lanka, S. (2000). Arrival Dates of Southwest Monsoon Rains – A Modeling Approach. Tropical Agricultural Research, 12, 265–275.

Acknowledgements: This post is based on a paper published with the support and guidance from my supervisors/ co-authors Dr Erandi Lokupitiya (University of Colombo, Sri Lanka), Dr Pramuditha Waidyarathne (Coconut Research Institute, Sri Lanka) and Dr Ravi Lokupitiya (University of Sri Jayewardenepura, Sri Lanka). 

This blog is written by Cabot Institute member Charuni Pathmeswaran.
Charuni Pathmeswaran

How engaging citizens can help to shape green cities

In order for European territories to be more environmentally and socially sustainable the involvement of citizens is key. Experiences throughout Europe show us that developing strategies to improve the engagement, collaboration and communication with local stakeholders – across diverse realms and thematic domains – is essential to ensure an effective outcome. During European Green Week, a workshop organised by DG Environment, was conducted to showcase some inspirational experiences in terms of sustainable urban development, health and waste management from different European cities.

Speakers included Mauro Gil Fournier (Estudio SIC), Professor Rich Pancost (Director of University of Bristol Cabot Institute for the Environment), Silvia Moroni (AMAT), Paola Robalo (Centro Ciência Viva do Alviela), Sietse Gronheid (Wasted Social Enterprise) and Igor Kos (City of Maribor).

Rich Pancost speaking at EU Green Week. Image credit BristolBrussels.

[Rich Pancost contributed on a variety of issues, largely arising from Cabot Institute and Bristol City engagement, but spoke primarily about the Green and Black Conversation and Ambassadors programme.  He emphasised the importance of engaging with marginalised groups, the fact that they have much to teach ‘established’ organisations, and the fact that inclusion requires far more than good will but hard work and appropriate financial investment.]
There was much feedback from the workshop as to how citizens could help to shape green cities which included:

  • We need to consider different levels of citizens’ involvement: consultation, participation, co-creation. For this reason we always have to consider who is involved and who is excluded from every process.
  • People are involved in topics they care about, so in order to get out of our elitism we need to address issues that really matter to most people, especially those people that are often not actively engaged. This is what was experienced by the Green and Black Ambassadors during the Bristol Green Capital year, where a community radio station with a focus on the local African-Caribbean community (Ujima Radio) framed environmental discussions and training around the perspectives of local community members.
  • Topics such as air quality, circular waste management or water pollution are hard topics to get people involved in, whilst topics such as food or green spaces are often more recognised by people because the feel ‘closer’. For this reason Milan, which is taking part in the Air Quality Partnership of the EU Urban Agenda, is working on developing an Action Plan that will actively address citizens’ involvement through a concrete toolkit.
  • For people to be engaged we need to involve them throughout the process and not just at the end to show the results. This is what has been experienced in Portugal by the Science Centre in Alcanena that is involving the local community in monitoring water quality, polluted by the local industry, in order to understand the roots of the problems and develop together possible solutions.
  • In order to get people involved in long term change we need to deliver short and medium term results that they can appreciate. This is what is being done in Maribor, that is developing a long term circular economy strategy and is creating festivals, schools events and fairs to get people involved and experience some of the changes taking place in the waste, such as for the biological waste turned into compost for community gardens.
  • Participatory processes that really get people committed, beyond a consultation, require people with professional skills of moderation and community engagement, which should therefore also be economically remunerated in order to ensure long term commitment. This is what is experienced by in Amsterdam, where through the Wasted project circular waste cycles are an opportunity to create complementary currencies in partnership with local enterprises.  The same is true for engaging with marginalised groups who have to sacrifice precious time to contribute; we cannot extract free labour from anyone but especially groups that are already marginalised by structural inequities.
  • For environmental and societal transition to take place we need to ensure that it also affects economic and financial models in an inclusive and participatory way, otherwise large parts of our society will keep being left out. This is what has been done in Madrid through the MARES project that develops social economy cooperatives around sustainable mobility and energy production.
  • Skills around social media and communication tools need to be addressed in order to reach out to people, yet they might be more effective tools for consultation rather than co-creation.

This blog was written by Daniela Patti (Eutropian) and edited by Amanda Woodman-Hardy (@Enviro_Mand) and Professor Rich Pancost (@rpancost) from Cabot Institute for the Environment.