The arguments for increasing food demand are well publicised and well understood. By the middle of this century, the planet’s population will top nine billion, presenting a third more mouths to feed. Much of the world is getting richer, which leads to changes in diet such as increasing meat and dairy consumption, foodstuffs that use up more resources than crops. Countries are also becoming increasingly urbanised, leading people to want food that is cheap, convenient and, inevitably, wasted. Current trends project that by 2050 demand for food may increase 60-110%.
On the other hand, there is a finite amount of land. The increase in yields from the Green Revolution of the 20th century has been driven by improvements in crops and agricultural techniques, not by putting more land into use for farming. There isn’t much scope to further increase the area of agricultural land globally. If we need more food and aren’t using more land to grow it, then increasing the overall crop yield must come through intensifying production.
But – and it is a big but – the intensive nature of the Green Revolution has come at a high cost: soils are degraded in many areas, water bodies are polluted and the functioning of marine systems is affected, air quality is reduced, and biodiversity is affected by land clearance and heavy use of agro-chemicals. Agriculture accounts for about one third of all greenhouse gas emissions, which plays a major role in climate change.
The land provides food, fuel, forage, fibre, water, flood protection, climate regulation and holds cultural value. These are goods and services which we value, but in many cases don’t pay the cost of. They are underpinned by environmental and ecological services, “ecosystem services”, that are like interest accruing from a capital sum in the bank. If we spend the natural capital, eventually the services will decline and fail.
The trouble is that it is very easy to spend the natural capital, assuming it has little current or future impact. Soils can be mined for nutrients or allowed to erode. Fertilisers can be applied to boost yield, but which affect the quality of the air, nearby vegetation and water. Pests can be killed by pesticides, but can also affect pollinators like bees and the pest’s natural enemies, which in turn leads to the need for more pesticides. Biodiversity is eroded bit by bit until populations are driven locally, regionally, and nationally extinct.
Recognising that intensive agriculture has often come at a high environmental cost, the argument goes that if demand drives us toward intensification we should do it sustainably and preserve the ecosystem services that we value. “Sustainable intensification” is promoted as the way out of the paradox.
But is such a thing possible? It’s absolutely true that agriculture can do far more to be sustainable. Using resources more efficiently is clearly possible: applying fertilisers in the right amounts, in the right places and at the right times, minimising the impact of pesticides, using efficient irrigation systems and water storage to avoid unsustainable water extraction, and managing soils better.
All these are possible, and technology is improving all the time to help. But going beyond “reducing the harm” to “improving the natural capital” means costs – either in investment, or in lost profits. To preserve natural capital means setting aside land managed as habitats to boost biodiversity. It requires forests to be left, not converted to timber yields, soils to be invested in loss-bearing fallow years, and so on. Organic farming, for many seen to protect natural capital best, yields 50-80% of conventional intensive practices. Producing food as sustainably as possible would require farming in ways similar to organic farming, but with some land taken out of production to provide sufficient habitat at the landscape scale.
So can we have an intensified agricultural system that can feed our growing population and natural capital we can bank on? Where there is unlimited demand, there will always be an economic incentive to ensure land turns a profit. Profit and sustainability do not naturally go hand in hand, as sustainability implies forgoing the potential of gains from eroding – selling – our natural capital.
“I’d like to be more sustainable but can’t afford to”. Until we recognise that the cost of food is subsided by the environment and find ways to pay the real value of what it is that we value, the economic incentive to profit will always trump sustainability. The tragedy of the commons is with us still.
Tim Benton, the UK Champion for Food Security, discusses this topic tonight in a talk at UEA, Norwich, 7.30pm (free).