Can We Make Our Demand for Food Sustainable and Secure?
Demand for food is growing globally, with some estimates suggesting the need for 60% more food while using less land and less water in the face of a changing climate. Addressing over-consumption and waste are routes to reducing demand, but these probably won’t balance the need to produce more food. To what extent can we increase food production in a way that is both sustainable and secure?
Food is something that everyone needs all the time. Given the ability to eat more than is good for us, many of us do. Much of the food stuffs we particularly like are also demanding to produce from energetic or environmental perspectives; beef, for example, converts plant nutrients to muscle at about a quarter the efficiency that chickens do.
Wanting to eat more, and more “expensive to produce” food, is entirely human: as people get richer they eat more and this has been a sustained trend throughout history. As, on average, the world is getting richer, the demand for food per person reflects this trend and is increasing. This, coupled with significant population growth, especially in sub-Saharan Africa and Asia, underlies the FAO’s1 estimate that global food demand will increase by 60% by 2050.
Food Demand is Outstripping Supply
We are experiencing the third spike in food prices in the last 5 years. Increasing food prices may not only lead to a rise in starvation and malnutrition disorders in the developing world, but can also undermine governance in the most fragile economies. For instance, food price riots were a contributory fact in the civil unrest that sparked the ‘Arab Spring’.
Breakdown of social order has consequences that are felt far beyond the country in question, whether via an increased need for trade, or aid, or increasing migration rates, and results in knock-on effects on global order. Increasing food prices also enhances the disparity between the rich and the poor in any nation; leading to the potential for a variety of social ills as well as malnutrition and inability to access food.
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The US Census Bureau estimates that there were nearly 50m people in the US who were food insecure in 2010. Thus, the demand-supply imbalance, accentuated by extreme weather events, is beginning to have significant consequences throughout the world.
A global aspiration to eat ‘westernised diets’ may not be attainable, and even if it is, it will not be sustainable. The World Wildlife Fund’s 2012 Living Planet report2 suggests that “if everyone lived like an average resident of the USA, a total of four earths would be required to generate humanity’s annual demand on nature”. A recent report on water from the Stockholm International Water Institute3, sets an upper limit of about 5% of meat in the average diet, purely due to water constraints, by mid-century.
As the world gets richer, more people can afford to eat like us, but equally, global resources are not available for the level of production that would be required. The health drawbacks of the westernised diet are also becoming increasingly clear. Both factors suggest the need for a change in our expectations of what we can demand to eat.
By tackling waste, as well as consumption, we have a mechanism to reduce overall demand. At the moment, richer people tend to be wasteful of food, and, in the UK, we typically throw away about 20% of the food we buy.4 The more we can tackle waste and unsustainable consumption, the more we can relieve the pressure on increasing the global supply of food.
What is Stopping Us Growing More?
Managing waste and over-consumption will not fully counteract the growth in demand for food – partly because demand is growing faster than our ability to change the consumption and purchasing behaviour that drives the food system in its current configuration.
‘Growing more’ is not as straightforward as it has perhaps been in the past. Firstly, as a first approximation there is no more land available, perhaps even less. A map of the global land area under pasture or cultivation clearly shows that the majority of the available land area is used; the remainder is typically under rainforest. Converting rainforest to agricultural land would be the fastest way to accelerate climate change – not to mention the inestimable loss of biodiversity.
Secondly, competition for water is increasing, such that projections suggest that over 50% of the world’s population will exist in areas where demand has outstripped supply by 2050. Already agricultural production drains about 70% of the world’s available fresh water, and clearly societal and economic use of water (by industry) exerts a growing demand. Thus, for many areas of the world, any increase in production to meet demand cannot rely on anything approaching a proportional increase in water use.
Thirdly, the considerable worldwide increase in production in recent decades has been underpinned by the use of a broad range of agro-chemicals, including synthetic fertiliser and pesticides. Both of these have negative environmental impacts, and in some areas, there is a growing societal pressure to reduce their use. Synthetic nitrogen fertiliser also requires significant energy to manufacture, contributing to agriculture’s greenhouse gas (GHGs) footprint. And again, there is utmost need to address issues to minimise GHGs to prevent further climate change.
Farming is affected by the weather, not the climate, on a daily basis. Hansen et al5 show that the weather’s variability is increasing much faster than the climatic mean is moving. The daily news is replete with reports of “once in 100 years” weather events occurring year after year. As weather has a particularly large impact on biology, the increasing frequency of extreme weather events is worrisome. For example, for many crop plants, a rise in temperature of 30% – especially around flowering – results in a significant drop in yield.
Thus, whatever the climatic mean, a few days of heat wave at 35 degrees can be catastrophic to yields. The past year has witnessed drought and extreme temperatures in both Eastern Europe and the mid-West; and, as part of the same overall climatic phenomenon. Northwestern Europe experienced a very wet summer, which had significant repercussions on local yields. Together, these northern hemispherical events impacted net agricultural production, leading to an increase in global food prices.
Thus, whatever the future may hold for climate change, the impact of extreme weather events is already observable. We are witnessing a period where supply does not always meet demand, which contributes to increasing food price volatility.
Greening Agriculture: The Need for Sustainability
The recent history of agriculture has undervalued the natural capital that underpins our very existence. Thus, in addition to the constraints on production growth due to climate, water, land and resource availability, agriculture needs to become more sustainable. The environment provides a range of services that we value: soil biodiversity helps with soil fertility and carbon storage, vegetation and soils filter and clean water providing access to fresh water; insects pollinate crops, increasing yields, and others may be the natural enemies of pests and so on.
For example, recent work indicates that tropical forests provide a range of services to the local population: fuel, fibre, food, pollination of crops, prevention of soil erosion and ground water storage. It is also increasingly recognised that they release water into the atmosphere, along with organic molecules, and that, coupled with the surface texture and reflectance, help to stimulate cloud formation essential for rainfall onto nearby land.
Agricultural production needs to become more environmentally sustainable because, without doing so, the ability to grow and sustain production is threatened. This transition to sustainability will need to be driven by a range of innovations.
An important area for innovation will be increasing ‘precision agriculture’ which encourages smarter farming: applying fertiliser on those patches in the field which most require it, and only at times when it is necessary. New agricultural equipment and techniques will allow weeds to be sensed using cameras and sprayed, without the need for spraying the whole field. Proper management of soil will both enhance fertility and store carbon and water, useful in times of drought, with further prevention of erosion. Growing more with less will inevitably call for new varieties – whether from modern molecular biology – coupled with conventional breeding, or via GM technology.
New ways of growing food – such as aquaponic systems in cities, and perhaps also artificial meat cultured from stem cells without using the organism – will inevitably be part of local solutions. What is not possible is cheap, plentiful, extensively grown food (such as from organic systems) for everyone, because there simply will not be enough land available to meet demand.
We also need to protect and enhance ecosystem services. A recent estimate suggests that small wasps provide £50 per hectare of pest protection services reducing the need for spraying for aphids. Pollination provides over £400m of benefit to the UK. By recognising these values, and the value of soils and water, rather than regarding them as ‘free’ and valueless, it makes economic sense to manage some patches of land to ensure that these services are maintained, for example, in agri-environment margins. By being smart about the placement and design of such margins, and with specific management of other non-cropped areas, it is possible to design a ‘multifunctional landscape’ that provides the services we require and produces the food we demand.
Smart agriculture then has a number of important components: at the landscape scale we need to exploit more efficient farming methods, producing both food and other ecosystem services. However, different landscapes will differ in the range of foods and services they can produce, and smart agriculture will increasingly require specialisation of land use: if the environmental cost is low, and the yield high, an area may be most efficiently used for production (and vice versa for ecosystem services).
In other words, producing food efficiently over a small area where the land is best suited would be more appropriate than doing it inefficiently over a larger area, which would mean increasing land pressure and undermining more ecosystem services.
Clearly, smart agriculture requires a shift in thinking, policy and governance, to prevent the market simply driving for production at all costs. This is possible, but it requires the recognition that land use decisions impact on more than the land in focus.
Can we Produce Enough Food Sustainably?
Yes but ...
First, we need to reduce demand in order to relieve pressure on land and natural resources. This requires each of us to moderate our own demands for food, and decrease our waste. In turn, moderating demand requires a much better general understanding of what makes a nutritious diet and what can be sustainably produced.
Second, we need to be smarter about agricultural production and eco-system management. Should production rise without increasing the land area - and without doing it more sustainably – then this would call for greater efficiency in terms of our use of resources.
Third, we need to recognise that we live in a global world: many of the ingredients in our daily diet come from all round the world. Often, the transport component of the total carbon budget is relatively small – so eating local may not make sense on intrinsically sustainable grounds; in fact it may perhaps be most efficient to specialise production of goods to areas where they grow best, rather than trying to produce everything everywhere.
And fourth, we need to recognise that a global food market implies that the food we consume comes with environmental costs which may be paid anywhere in the world. We could turn the EU into a ‘green and pleasant land’, with low and extensive production and high environmental protection; but our demand for food would not decrease, so we would simply import more – paying others to carry the environmental burden we locally avoid. Furthermore, under-exploiting our very productive farmland will reduce global production, and increase global prices, which may impact most on the poorest people – here and abroad.
Thus, in our agricultural landscape, the stakeholders are not just our citizens, but also people in other parts of the world whose local land will be affected through market signals as we change our land use.
The challenge for us is to find the right balance between what we demand, what the environment needs, and what other people need from us (in terms of food imports and exports). This is not easy, but we are all global citizens, increasingly connected through the global food system.
Prof. Tim Benton is Professor of Population Ecology at the University of Leeds and is UK Champion for Food Security. His research interests lay in the agri-environment sphere; his work focusing on the ways farming is responsible for ecological dynamics.
 Stockholm International Water Institute report.
 WRAP (2011) New estimates for household food and drink waste in the UK.
 Hansen J., Sato M. & Ruedy R. (2012) Perception of Climate Change. PNAS, 109, 14726-14727.