About Me

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London, United Kingdom
I am an engineering academic at University College London where I work on the sustainability of urban water systems. I am interested in the role of engineers and technology in sustainable cities.

Thursday, 13 September 2012

Why I worry about desalination

Global desalination capacity is currently growing at around 9% per year, much faster than the global economy (3.5%) and population (1.2%). Most of the growth is occurring in the Middle East North Africa region, but capacity is rapidly expanding in Israel, the US and Australia. London's first desalination plant was commissioned in 2011. The Water Corporation of Western Australia commissioned its first desalination plant in 2006 and will triple capacity to 145 billion litres per year by the end of 2012, providing a 'climate independent' source of water meeting around half the state's demand. By the end of 2013 desalination is predicted to meet 85% of Israel's domestic demand, following the construction of a 100 billion litre per year plant at Ashdod. Desalination is seen as a core element of climate change adaptation, a response to drying climates.

Discussions about the global water crisis usually begin by pointing out that only 0.01% of all the water on the planet is available for human use - 97% is saline and the rest is either frozen or inaccessible. Desalination puts an end to that. Desalination effectively makes all the liquid water on Earth available for human use, but at what cost?

The most obvious cost of desalination comes from its energy requirements. Most new desalination is based on reverse osmosis membrane technologies, which have seen dramatic improvements in efficiency and cost in recent years, but remain an order of magnitude more energy intensive than conventional water treatment technologies. Desalination represents the ultimate trade off between climate change mitigation and adaptation - burning fossil fuels to avoid the impacts of increasingly frequent and intense droughts. Isolated desalination plants such as those in Sydney, Perth and London are powered by renewable energy, which is clearly preferable. However, in the wider context of moving to a low carbon economy, water utilities along with other sectors would be reducing overall energy use and switching to renewables, rather than using renewable energy to justify unprecedented energy demand from this new technology.

The thing that really worries me about desalination is that it essentially changes our relationship to water and the environment. Water, the great connector of life, becomes merely an industrial product, subject to the economic rules of substitution, with technology stepping in to meet endlessly growing demand at increasing cost of production. The people of the modern states of Western Australia and Israel, always tenuously perched in their desert surroundings, can now live without limits, fundamentally reorienting their sense of place and respect for their locality.

But the promise of no limits is always illusionary. As the adaptation-mitigation trade off shows, Prometheus is always punished. Water consumption inevitably leads to water pollution, as it flows through our homes, offices and factories, and back out again, contaminated, through our drains, to be treated once more, using high energy processes, before discharge to the environment.

Desalination is undoubtedly necessary in situations of acute shortage, as a stop gap measure in extreme events. Moving the entire basis of a water system to desalination, such as is taking place in Israel and Western Australia, is another matter. It is a responses to climate change that more firmly than ever entrenches the patterns of development that led to climate change. Living without limits is what got us into this mess. Breaching those limits is a very worrying place to go looking for solutions.



Saturday, 1 September 2012

Feet on the ground

It is graduation season at UCL. I like graduation. For one thing, it appeals to my Catholic sensibilities - men and women in funny hats and gowns, the procession, sitting still for long periods, speeches about the meaning of life, music to open and close. My suggestions for singing and incense have not yet been taken up, but I go every year and enjoy it nonetheless. Of course the best thing about graduation is seeing my former students, remembering their trials and triumphs as they cross stage, meeting their families and lovers, and celebrating with them as they step out into the world on their own terms.

Anyone who has ever attended a university graduation knows that it takes a long time. There is a long list of names to be read out, and a long line of people waiting for their moment. We all find ways of occupying our minds. Members of the platform party face the slight pressure of being on view the whole time, knowing that folks in the stalls may well be occupying their minds by scrutinising our every scratch or twitch. We should look dignified, interested, happy and awake at all times.

I occupy myself with shoes. As the graduand walks to the stage I look at their face and smile, then as they walk in front of my I take note of their only other distinguishing feature, their shoes. Over the last few years I have noted with horror the rise and rise of the heels on women's shoes. As a woman who came to consciousness in an age where stilettos were thought of as modern man's answer to foot binding, shoe fashion of the last five years baffles me. You simply cannot participate in society on equal terms with people in flat shoes if you are struggling to walk. What if one of the people in the flat shoes decides to attack you? How will you run away? I like high heels and wear them occasionally, but the trend towards higher and higher shoes is bewildering and dangerous. With models tumbling off runways, surely this craziness has to end? This year as I walked to the venue I wondered if I would see an end to the madness, following what I hope is the fashion trend against super stilettos and mega platforms, and back to wearable shoes.

First up were Biochemical and Chemical Engineering. The horror. The heels. Higher and more structurally implausible than ever. Smart, elegant women, wobbling dangerously across the stage on the path to becoming an engineer. Then the inevitable happened. The shoes claimed a victim. A woman tripped and fell as she left the stage. She picked herself up, the Dean checked that she was OK, and the ceremony continued.

Next were Civil and Environmental Engineering, my class. Much to my relief our women were on the whole wearing flattering, flatter shoes. Some wore heels, but very few were in the spine deforming, ankle twisting, nose bleeding range. This could indicate that our students have met their health and safety learning outcomes to a higher standard than their colleagues in the other departments, but I like to think it is because they are more hip. Our women are in the vanguard of foot fashion, and are marching on their way to becoming professional engineers with both feet on the ground.

The women of the Engineering Class of 2012 are smart, beautiful and ready to take on the world. I have no doubt that they will succeed. I can only hope that more of them will choose footwear that will leave them no excuses for not keeping up with those in flat shoes.