The Great Agricultural Transition
Agriculture is a leading cause of deforestation, global emissions, and nitrogen run-off. What might a sustainable food system look like?
Agriculture consumes more land area than any other human enterprise on the planet. Humanity’s demand for food is growing alongside increasing pressure on the environment and climate instability. To best preserve biodiversity means making space for biodiversity, but this is at odds with humanity’s demand for cropland and shrinking arable regions.
Decoupling agriculture from its dependence upon natural cycles by increasing the efficiency of the food system and bringing primary agricultural production into cities is a solution with enormous potential to decrease pressure on natural systems while ensuring humanity is able to feed itself.
Increasing the Efficiency of the Food Production System
Reducing the footprint of agriculture is perhaps the easiest and most necessary first step to overhauling our agricultural system. Plant-based diets are vastly more efficient than diets high in animal products from a land-use perspective. According to the UN Food and Agricultural Organization (FAO), 77% of arable land is used to raise animals, while only providing 18% of global calorie supply.
Cattle ranching and soy production for animal feed are the leading causes of deforestation in the Amazon, accounting for about 70% of deforestation in Latin America. This is especially concerning as people tend to consume more meat as they become wealthier.
If we were to eliminate or substantially cut consumption of animal products, we could feed far more people just with the land already under cultivation. Transitioning to plant-based diets could also reduce agricultural carbon emissions by as much as 50%. This is critical, as agricultural emissions account for approximately 25% of global carbon emissions.
We could further reduce the footprint of land required for agriculture by dramatically cutting food waste. Presently, in the United States, about 30% — 40% of all food produced is wasted. Food waste could be diminished through laws and regulations that target supply-side food waste and educational programs that target consumer habits.
The combined effect of largely or entirely plant-based diets with substantially reduced food waste would dramatically increase the efficiency of our food-system, maximizing the amount of functional calories we can obtain from the land.
Food production could then be centralized in massive vertical farms closer to or within city limits. This would allow for a decoupling of caloric generation from natural variability in the face of a rapidly changing climate and therefore greater food-security.
Bringing agriculture closer to cities could reduce food transportation costs, further reduce food waste as production could be more closely tied to local consumption patterns, and decrease the risk of supply-side disruptions. Food security risks due to pests, droughts, flooding, and other similar factors would also be essentially eliminated due to the tightly controlled environments of indoor farming.
This would further increase the efficiency of the food-system, as hydroponically and aeroponically grown crops can grow many times more calories per hectare than conventionally grown crops using far fewer resources such as water, pesticides, or fertilizers. Other emerging technologies such as lab-grown food can further improve the efficiency of our food production system.
Closing the Nitrogen Cycle
The industrial production of nitrogen-based fertilizers has broken the global nitrogen cycle. Relatively inert atmospheric nitrogen is turned into fertilizer, which is then spread across thousands of acres of crops. Along the way, large quantities of nitrogen get washed into various watersheds and eventually the ocean.
This has proven disastrous for aquatic ecosystems. Fortunately, the aforementioned changes to our food system would both decrease the amount of fertilizers necessary to grow crops and minimize fertilizer lost to the environment.
The nitrogen cycle could then be brought full-circle by processing municipal effluent to extract all available nutrients and then feeding those nutrients back to crops in that city’s vertical farms.
Tight coupling of the waste stream and food production mirrors natural systems where the rapid cycling of nutrients minimizes losses. Coral reefs and rainforests are natural examples where nutrients are rapidly and efficiently cycled throughout the system, and are generally bound to living organisms. Nutrients are quickly reabsorbed when an organism dies or excretes waste.
Similarly, in a system where municipal waste streams were connected to the source of agriculture, nutrients would be self-contained within cities and losses to the environment would be minimal. By radically reducing the need for new fertilizer and nitrogen losses to the environment, agricultural emissions could be further reduced.
Additionally, community composting programs could collect food-waste to dramatically decrease methane production in the waste stream and recapture those nutrients as well. This compost could then be used to supplement soils in urban parks and outlying regions where permaculture allotments and food forests grow crops that do not perform well in an indoor environment.
Challenges and Solutions
The two primary shortfalls of overhauling agriculture as stated are that it would be highly energy intensive and require a high upfront cost. Energy intensity is only a problem as long as we derive energy from fossil fuels and similar environmentally destructive methods.
The transition to renewable energy and energy storage systems is already well underway, due to the favorable economics of solar and wind. The best candidate for cheap, renewable, and virtually unlimited energy, nuclear fusion, is still just over the horizon.
Regardless, transitioning away from fossil fuels is a requirement for a sustainable society. The unfavorable economics of indoor farming could shift as food insecurity increases, the energy grid transitions, and the potential for carbon sequestration increases the perceived value of unmanaged lands.
Moving agriculture to urban centers would be a dramatic departure from both our present and historic practices, but is achievable if invested in sufficiently. Doing so would provide increased food security and reduce agricultural related pollution, as variable climate patterns become more difficult to predict and global arable land decreases.
As a bonus, it would free up an enormous amount of land for conservation, ecological restoration and rewilding, and associated carbon-sequestration through natural systems. If we embark on transforming our society to the extent necessary to withstand climate breakdown, then transforming the way we consume and produce food needs to be one of the highest priorities.
Urban food production and changes in our behavior offer us a comprehensive solution to the challenge of maintaining food security through the 21st century. Let’s get to it.