Within the next few decades, the world will need to increase food production to support a growing population also striving for higher shares of animal protein in their nutrition. But food production always affects the environment: Nitrogen runoff from fertilizer has led to major pollution of waterways around the world, while deforestation to extend cropping areas and methane emissions from livestock increase the amount of greenhouse gases in the atmosphere, adding to the problem of climate change. In order to increase food production, without further increasing nitrogen pollution and greenhouse gas emissions, agricultural systems will need to innovate.
In a recent study, IIASA researcher Wilfried Winiwarter explored the range of solutions for future agriculture, researching current literature for ideas and innovations, and examining their feasibility and potential.
“I call this a science fiction paper,” says Winiwarter. “It’s not about what exists and can be implemented immediately, but about the possible innovations that could conceivably be developed in the long-term.”
The study focused on innovations ranging from seemingly simple behavioral changes to radical technological fixes as discussed in more detail below. It reviewed existing scientific literature, mostly peer-reviewed, including design studies that quantified potential environmental effects of such innovations.
Precision farming refers to technological solutions to improve yields and reduce waste in farming. On the one hand, precision farming can refer to the mechanization of agriculture that may not be environmentally benign, but on the other side, to optimized processes that reduce losses and impacts on the environment.
“Much is already happening,” says Winiwarter. For example, milk production in Europe now occurs mainly in large sheds, with indoor cows, not with free-ranging cows in idyllic meadows. While this industrial approach to agriculture makes food cheaper and more abundant, it also raises questions about animal welfare, and the massive scale of such operations can lead to increased greenhouse gas emissions.
Precision farming can also be used to reduce the amounts of fertilizers or irrigation used, for example, using soil sensors or other high-tech infrastructure to detect exactly what is needed and apply no more than necessary.
Genetic modification (GM) of crops allows scientists to equip organisms with certain traits in a much more directed way than traditional breeding. It presents the potential to increase yields, provide drought or pest resistance, or introduce additional nutrients to foods that lack them. GM is already widely used in some crops (mostly to increase pesticide resistance and thus also pesticide application), but in Europe the subject is controversial and GM foods are viewed negatively
Winiwarter notes that the side effects of genetic modification are in general not well understood, and thus possible impacts are quite unpredictable.
The study looked into the growing popularity of urban gardening, the “green” trend to grow food in individual gardens inside cities. While urban gardening is generally considered environmentally benign due to small-scale, low transport needs and high personal motivation, Winiwarter notes that it doesn’t have the potential to produce staple food required to feed large populations. One key background study calculated that urban gardens had the potential to produce 10% or less of the food needed in a given city.
“You need space to produce food,” says Winiwarter.
As people move to cities and land becomes scarcer, one logical concept is to construct skyscraper “farms” with multiple levels of vegetables growing in hydroponic or aeroponic tanks – like giant, multistory greenhouses. “Compared to an open field, you could produce 200 times as much food on the same space,” explains Winiwarter. “In a city like Vienna, you could conceivably produce all the food for the city within city limits.”
Another advantage of vertical farming is that it could be organized to avoid waste: whereas fertilizer in a field runs off or percolates through the soil into the water table, a vertical farm would employ nutrient solutions that could be contained and recycled.
However, the sunlight needed for photosynthesis could not so easily be multiplied. Instead, the process would require artificial light, which means enormous amounts of energy – even if efficient LED lighting could be employed. “The question is where you would get that energy,” he says.
Another radical idea for food production is to take meat production off the farm, and instead culture animal cells in petri dishes to grow artificial meat in a laboratory in a nutrient solution. Indeed, the first hamburger from cultured meat was produced in 2013. But Winiwarter notes that meat from the laboratory may not be less resource-intensive than the real thing, since it would need energy, heat, light, and nutrients, which all would make the process extremely expensive, even under ideal conditions. He says, “Upscaling such a process may come with a number of negative surprises – from sanitary issues to pollution as a side-effect of tackling potential health threats. Little is known on the potential environmental effects in a life cycle.”
“In general, meat has a higher environmental footprint than a vegetarian diet,” says Winiwarter. “It takes more area to produce feedstock for an animal than it would to produce vegetarian food for humans.”
Europe in particular has a high level of meat consumption, Winiwarter explains, so cutting meat consumption in the region has a large potential. In much of the highly populated areas of Asia, people consume a mostly vegetarian diet. As these countries become richer, increased consumption of meat and milk production is observed when people tend to copy European lifestyle. If Europeans were able to cut down on meat consumption and treat themselves with a more healthy diet, positive environmental effects may even spread to world regions where European food patterns may serve as an example.
Agriculture, like a high-tech industry, will continue to develop dynamically in the future. Many paths of development can be imagined, and have been described in scientific or other literature. “There is no ‘silver bullet’ to resolve the environmental damage of agriculture”, Winiwarter says. Instead, future innovations will need to be carefully monitored and evaluated for potential environmental effects, in order to minimize damage of nitrogen pollution and maintain livelihood on earth.
Winiwarter W, Leip A, Tuomisto HL, Haastrup P. 2014. A European perspective of innovations towards mitigation of nitrogen-related greenhouse gases. Current Opinion in Environmental Sustainability. http://www.sciencedirect.com/science/article/pii/S1877343514000396
By Katherine Leitzell, IIASA Science Writer