Tackling the nexus of sustainability

Engineers are well placed to lead in the sustainable development challenge if they apply more ‘nexus thinking’ to their work, says Krisztina Bordacs.

We are faced with something of an information overload in the sustainability sphere. There is a mountain of data produced every week on environmental issues, management of resources, and methods to tackle these problems.

It is no mean feat getting to grips with the myriad pieces of analysis and ideas. And to add to it, there is the further problem of a lack of clear definitions, and ambiguity about what we mean by issues like “sustainable development”, “circular economy” and “climate change mitigation”.

The UN has attempted to create some common definitions within its sustainable development goals. These are a group of 17 missions – which include ensuring access to clean water for all, universal availability of reliable and renewable energy, and the creation of resilient infrastructure – which together would allow truly sustainable development. Taken together, the goals aim to take the idea of sustainable development and make it something tangible, which is more than just about the environment, but about the human race being able to live sustainably.

This has been styled the “livelihood puzzle” and it throws up the difficult challenge of marrying human need for water, energy and food, while protecting our planet. A complex puzzle no doubt – a challenge in which engineers and sustainability professionals have an important role to play, and one that they should relish the opportunity to tackle.

The key to progress in the sustainability challenge is “nexus thinking”. Coined by The World Economic Forum, nexus thinking means considering the complex interrelationships and interconnections when approaching the human need for water, energy and food.

It is a helpful system of thinking, but one major problem is that when considered on a global level, food scarcity is always put first, as it is undoubtedly the biggest concern. The risk is that the need for utilities – equally as important for sustainable development – is relegated to secondary importance.

The challenge, then, is for engineers and policymakers to find ways to divide the obstacles that stand in the way of sustainable development into a manageable size, meaning they can be analysed and tackled individually.

Importantly, we are already on our way to doing this. There are established engineering and scientific principles that can be used to understand global imbalances, and give us the tools to make decisions that consider the whole ecosystem – nexus thinking.

Let us take an obvious example. We can compare the energy needed for water production with the water requirements for energy production, which would lead us to finding a sustainable solution.

A more technical example is the need to balance concerns in the removal of phosphorous from wastewater. If phosphorous is not taken out of wastewater, it can cause an excessive richness in water which causes a dense growth of plant life. A common technological process can achieve phosphorous removal, though in a large system it creates struvite, a nuisance by-product that tends to clog up pipes.

But, by applying nexus thinking, struvite is no longer perceived to be a nuisance, but rather a potential blessing. Struvite is a readily usable fertiliser, and with the right engineering technology it provides a solution to securing global food supplies. Indeed, this process is already being used successfully and commercially for fertiliser production.

Biomass is another area in which the fusing of science and engineering, combined with nexus thinking, can create significant gains. The process of turning natural waste matter into useful energy is not now, but the application of it to waste treatment is novel. In effect, engineers have redesigned wastewater treatment so that not only is clean water produced, but also energy, and phosphorous fertiliser are created. This great example of joined-up, holistic thinking has seen the once two-stage process of wastewater and sludge treatment become quicker and more efficient. This system is beginning to catch on in the commercial market in the US and the UK.

To see more of this thinking, part of the challenge is to embed sustainability into organisations much more. Across the UK and the world, we are seeing sustainability move on to a higher plane of corporate thinking. It is no longer being viewed as a simple add-on, or an extra cost, but a crucial element in increasing efficiency and saving money, but this needs to be furthered.

The two examples given here highlight the role engineering and science has to play in breaking up huge, global issues into smaller problems. The engineering principles to help us unpick the sustainable development challenge are there. If they can be applied with joined-up thinking and policymaking, we will on our way to tackling the multi-faceted, complex and intertwined issues that sustainable development throws at us.