The word ‘nexus’ seems to be cropping up everywhere, but what does it mean for food security? Global Food Security Champion Tim Benton explains.
Following Christmas, often an annual festival of demand and excess, maybe January is the time to think about demand-management. At the end of last year, I was involved in a flurry of meetings with the term ’nexus ‘ in the title. Nexus essentially means interconnectedness, or binding together.
Agricultural landscapes provide a wide range of goods and services to society. These ’ecosystem services’ include the provision of food, fuels, fibre and clean water. Agricultural landscapes also provide biodiversity that aids production (such as pollinators, natural pest control and soil biodiversity) and support rural livelihoods as well as recreation, amenity, cultural and heritage values.
All of these services come from the land. So thinking only about one, such as food production, risks missing the interconnections between them. Therefore, the nexus is commonly associated with the inter-connection of food, energy, water and the other services land may provide.
In the broad sense, ‘nexus-thinking’ recognises that the land provides services but, crudely, whilst we can aim to drive up the production of one service, we are likely to drive down production of another.
For example, intensifying food production may require more water, impact on water quality, and may take more energy. But this leaves less water for energy production, and may require more of the landscape and so leaves less land to provide the other ecosystem services.
When I was “nobbut a lad” at university, I remember grappling with the economic notions of maximisation vs optimisation.
For simplicity’s sake, let’s assume that there is a trade-off between food production and water quality: the more food that an area of land produces, the more there is likely to be leakage of soil, nutrients and other agro-chemicals into water. We can use the land to maximise food production, or maximise water quality, but we cannot maximise them both. Instead, we can optimise the system to produce the “best” combination of food and water (however we may choose to define it).
Recognising the nexus forces us to adopt a systems-based or holistic way of thinking about the way the different things we want are inter-connected. For people of a certain generation, Douglas Adam’s fictional holistic detective, Dirk Gently, was the first nexologist. Dirk famously used the “fundamental interconnectedness of all things” to solve the whole crime.
Nexus-thinking implicitly forces us to switch from thinking about maximising to optimising, and implicitly also forces us to think away from disciplinary silos (food, or water, or energy or biodiversity) into inter- and trans-disciplinary thinking. Given that society wants so many things from land, how can we use land to provide an appropriate balance between them?
Nexus thinking clearly also throws up significant challenges about how best to use the land – best for whom?
What may be best for one sector or person may imply another sector or person loses out. Even if we were to be able to design smart landscapes, which provide societally optimal land-use for providing everything we want, what governance, policy or institutional mechanisms could be used to deliver the appropriate balance of services?
The challenge of managing the land to provide the range of services people want is only going to intensify. A recent paper indicated that if current yield-growth and demand trajectories are followed through by mid-century, and ignoring the impact of climate change, agriculture, globally, would require 120% more water for irrigation.
Given that agriculture currently accounts for 70% of the world’s abstracted water, it is difficult to imagine how even with innovations in storage and irrigation 70% can increase by 120% sustainably. This is especially because the 30% of abstracted water not used by agriculture is used by industry (a good chunk of that is water required for energy generation, including cooling) and domestic use, and both these sectors also face increasing demand.
The conclusion I take from that paper is that, whilst we need to recognise the interconnectedness of all ecosystem services, and we can optimise the nexus to produce a mix of services, ultimately, that will take us only so far.
Perhaps the only long-term solution is to make space for providing the mix of things we want by thinking about how we may change our demand. On a finite resource base, we can’t fulfil infinitely growing demand for natural resources.
We can’t have it all: so what is most important? What do we value most from land? Valuing the services from the nexus has got to be called ‘nexonomics’!
About Tim Benton
Tim Benton is GFS Champion and an interdisciplinary researcher working on issues around agriculture-environment interactions. Formerly, he was Research Dean in the Faculty of Biological Sciences, University of Leeds, and Chair of the Africa College Partnership, an interdisciplinary virtual research institute concerned with sustainable agriculture in sub-Saharan Africa. He has worked on the links between farming and biodiversity (and ecosystem services) for many years.