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More! (02/2021)

A model to feed the world.

Text: Catherine Weyer

The world population is growing – and with it demand for food. With a view to satisfying this appetite in the future, Ruth Delzeit and her team model how to make the best use of the land available to us.

World map from dried fruit and nuts
Ruth Delzeit and her team create models of how a growing world population could be fed. (Image: Pexels)

A farmer in the Swiss municipality of Hemmiken drives a tractor across his field. His mind is on his wheat: Will he be able to sell it for enough money to make his efforts worthwhile in the future? Will he even find buyers for his wheat five years from now? And what else will he be able to grow on his land if temperatures keep on climbing, heralding inordinately dry summers or fields flooded by torrential downpours?

These are the questions that Ruth Delzeit is trying to answer. The professor of global and regional land use change and her team at the Department of Environmental Sciences are modelling how we should best use natural resources going forward. The underlying issue is not so much how we want to farm the land, however – but rather how we must. “In the medium term, environmental concerns are something we cannot afford to keep putting off. Otherwise we’re going to run out of fertile soil for food production very soon,” Delzeit warns.

Dependence on international players

The agricultural sector is feeling the pressure from all sides: Growing population, growing prosperity, but also growing criticism of how we farm our soil – and what consequences it has for the natural world.

There are a host of factors at play: The farmer in Hemmiken lives and works in a small village, pays taxes to the local authorities and can exercise voting rights in Switzerland’s democratic system – but his future is closely intertwined with that of global players. And this is precisely what makes Delzeit and her team’s work so complex. “Right now, we have three doctoral researchers getting to grips with the model – I don’t envy them,” she says with a hearty laugh.

Minor changes, broad consequences

The team is working on a microeconomic model that computes states of general equilibrium, taking all sectors of industry into account. They simulate the effect of a particular change in the current situation. “We can use the model to calculate different scenarios, for instance by introducing a tax on meat consumption in industrialized nations,” Delzeit explains.

“As meat products become more expensive for consumers, their income is diverted to other products. Rising demand drives up the price of these products, too, altering entire trade patterns. For instance, the amount of animal feed imported by industrialized nations might fall, while vegetable imports rise. New market equilibriums emerge, and we can compare the situation with and without the tax.”

In order to make their predictions about the future of food production, there is a great deal that the researchers have to consider. How many people will live on the planet in the future? Will they want to eat more meat or legumes? How will global food trade evolve? Will we see a rethink of land use at local level? And what political decisions will have been made at national and international level by then?

Research aids decision-making

Requests for a prognosis on agricultural policy in the year 2050 are waved aside: “We can make forecasts for the next three or four months, but no longer.” And that is not what Delzeit is trying to achieve. “What we do is create tools that support decision-making,” she explains. She leaves the creation of a concrete roadmap to others – her team’s if-then analyses are intended solely as guidance. And that is how Delzeit believes it should be: “I think researchers should refrain from interpreting too much. And when they do, it should be clearly acknowledged.”

Delzeit first began dealing with issues of land use and the associated conflicts almost twenty years ago. Back then, she was doing research on biogas as a student assistant. “At first there was a great deal of hype, and no one was worrying about the negative effects,” she recalls. Then came the financial crisis of 2008, accompanied by a changing climate and food speculation on the stock markets. All of a sudden it was impossible to buy corn in South America, so the impoverished population starved while industrialized nations were converting corn into fuel. “It was undoubtedly a concatenation of various unfortunate events at the time, but it highlighted the emotional and moral charge associated with biofuels,” Delzeit says.

Intensive cultivation if sensible

It is situations like these that Delzeit and her team hope to avert with their scenarios. Is it better to find new areas for agriculture, or cultivate existing farmland more intensively? What impact will this have on food prices? And how will biodiversity be affected?

One of Delzeit’s findings is that more intensive agriculture is less harmful in terms of biodiversity than cultivating additional land. But once again, it’s not quite that simple. “In industrialized nations, agriculture can’t get any more intensive,” she explains. “We’re already experiencing problems with nitrate in groundwater as it is.” In other regions, such as sub-Saharan Africa, however, the situation is quite different: “In these areas, production could be massively increased through targeted fertilization without using additional land.” This approach would leave other areas untouched by agriculture, favoring local biodiversity.

So should Switzerland stop producing certain foodstuffs if they can be grown more efficiently elsewhere? “That’s not realistic,” Delzeit says. “Countries like to be self-sufficient. They don’t want to be completely dependent on other countries. The coronavirus pandemic has made it abundantly clear what can happen when desperately needed goods are suddenly withheld at the border.” In other words: another problem with no obvious solution.

Efficiency or robustness

And this is precisely what Delzeit has been trying to figure out over the last twenty years: What is the best way to guarantee food security decades into the future? Should we grow efficient crops in vast monocultures, or is it better to rely on old varieties that are more robust, but offer a lower yield? “India, for example, is falling back on old rice varieties that are better able to cope with flooding,” Delzeit reports. “This is a sensible adaptation to climate change.” Here too, however, there is no single right way to both feed the world and protect biodiversity, Delzeit reiterates.

Food production is not the only way to bring about change, the professor points out: “We need to think about caloric efficiency: How much effort is involved in ingesting 1,000 kilocalories – in the form of meat or high-protein plants?” The current trend toward increasing consumption of meat and dairy products in emerging economies will bring new challenges for global agricultural policy. This is another cog in Delzeit’s hugely complex model.

Lofty expectations

“Meanwhile, the issue of food waste offers huge potential,” she adds. In Switzerland alone, 2.8 million tons of food that could have been eaten are discarded each year. “We have extremely high expectations of what we put on the table, making us throw out food that is perfectly safe to eat,” she criticizes. It’s a luxury we can ill afford – and the brunt is borne above all by the natural world. This is another area in which Delzeit believes political incentives could make a difference. “If food were more expensive, it wouldn’t be wasted on such a massive scale.” But agricultural subsidies mean that supermarket price tags don’t reflect products’ actual cost – so consumers feel less compunction about discarding them.

Delzeit took up an invitation to work at the University of Basel in February, having previously headed the Environment and Natural Resources research center at the Kiel Institute for the World Economy. At Basel she plans to expand her research focus with projects on sustainable water use, regional case studies and an examination of subsidization policies. “Right now, both biofuels and fossil energy carriers benefit from state subsidies. It will be interesting to model how political decisions affect the use of these fuels in the future,” she remarks. Once more, there is little chance of a straightforward solution. But that is not what Ruth Delzeit is looking for.

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