Fresh from the Rio+20 conference, Tim Benton ponders the paradox of producing more with less.

Tim Benton

In the last weeks, I have attended an unsustainable flurry of meetings and discussions about sustainable intensification, sustainable agriculture or sustainable development (or all three together).

So what does “sustainable” mean, in the context of environment?

Agriculture, the world’s biggest industry, is rightly seen as the engine of development. It also generates the fuel, literally, that we all require. This analogy puts me in mind of the paradox of a perpetual motion machine: if agriculture is indeed an engine generating fuel, how can this be sustained into the future?

However, like a purported perpetual motion machine, where the motion is sustained by often unrecognised inputs (and forever), in the case of agriculture the hidden inputs are the natural capital that has been used extensively to support production. This natural capital has included the impact of fertilisers, land degradation, water use and contamination or erosion of general ecosystem services upon which many societally important functions depend.

Thus, for the engine of development to be sustained in the long term, it needs to manage its environmental impact to limit, or reverse, the erosion of natural capital.

Paradox and productivity

A current use of the ‘S word’ that is topical is in ‘sustainable intensification’.

If, as a first approximation, the amount of agricultural land is fixed into the future, and if yields need to grow to meet demand, then it implies greater output per unit area. This is one of the definitions of intensification – increase in outputs per unit area – and says nothing about the way that the intensification could be brought about (e.g. increasing labour vs. increasing capital inputs and industrialisation of farming practice).

But, in another paradox, the term ‘sustainable’ in sustainable intensification is equally weighted and implies that any increase in yields needs to be brought about by ensuring that the intensification is brought about, well, sustainably.

So what does sustainable agriculture look like? That is very difficult to say for three reasons.

First, sustainable is (probably) a relative rather than absolute term, in that we can always increase sustainability and there is no real threshold beyond which things are ’good’ and before which things are ’bad’.

Second, there are multiple currencies in which environmental impact can be measured – CO2, water and land use, biodiversity impacts etc. – and it is likely that different measures may trade-off against each other. For example, low-carbon farming may have lower yields, requiring more land to produce the same quantity and therefore having a higher impact on biodiversity.

Third, management of land in one place can have impacts far away; whether it is via pollution downstream, carbon emissions contributing to global climate change or indirect impacts working through the market – wildlife-friendly farming giving rise to lower yields in one place, sending market signals to intensify elsewhere. 

The complexity of incorporating multiple currencies and direct and indirect impacts near and far means the very definition of sustainable agriculture is moot and often misunderstood. There have been many attempts to define sustainable agriculture simplistically but the danger of simple measures is that they can lead to indirect negative consequences. For instance, transport miles are typically a very small component of carbon footprints which correlate very little with sustainability measured in terms of CO2, let alone farming’s impact on biodiversity. 

The best definition we can come up with is that agriculture is more sustainable if a practice does not cause yields to decrease but the environmental impact lessens. If yields do decrease, the agricultural practice may or may not be more sustainable depending on the way that the decrease in yield is made up via market mechanisms (and specifically how the shortfall is made up and where).

Ecology and efficiency

What is increasingly clear is that there must be two key elements to sustainable agriculture.

The first is increasing the sustainability of the agriculturally productive land. This can be brought about by increasing resource use efficiency, managing soils for fertility, reducing erosion (e.g. by land levelling), enhancing production-aiding ecosystem services (e.g. natural pest control) and so on. 

The second is ensuring that agricultural landscapes are managed such that they can continue to provide other services useful to society as a whole. These services will vary from place to place: cultural services (such as the look of the landscape, or maintenance of sacred sites), conservation of iconic biodiversity, management of forest fragments to contribute to local climate, fuel, pollination, forage provision, management of marginal strips to reduce pollution or flood control and so on. 

If agriculture proceeds at the expense of any or all of these aspects across the whole landscape, both local society and local livelihoods can be undermined. Thus, sustainable agriculture must be about ensuring that within-field practices are more sustainable, but that the matrix of non-agricultural land around fields contributes appropriately to ecosystem services; ’conservation margins’ are not about ‘bunny hugging’ but about maintaining a functioning landscape that provides many services for the good of all.

The “S word” is therefore a beast of many nuances. Being sustainable has to underpin agriculture because, in the long run, if agriculture suffers we will all suffer. 

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.

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