Contrary to the forecasts of most demographers, urbanization will reverse course as globalization unwinds during the 21st century. The eventual decline in fossil hydrocarbon flows, and the inability of renewables to fully substitute, will create a deficiency of energy to power bloated urban agglomerations and require a shift of human populations back to the countryside. In short, the future is rural.
Yeah, I wrote that, fully aware that it doesn’t fit neatly within the bounds of polite conversation. Unacquainted readers might find my ideas unorthodox, but I view normal political discourse as frustratingly constrained. For most people, most of the time, what they believe, consider, think about, etc., stems from the material world they inhabit and the social myths that reinforce and justify their way of life. This constrained world view tends to lock societies into a kind of trance where problems caused by their actions are pondered from a narrow set of possibilities that only maintains the status quo. Cultures therefore find it difficult to critique themselves and make sharp course corrections necessary to alter suicidal paths. It may take a child (or a somewhat uninhibited middle-aged guy like me), naïve about taboos or immune to reputational risk, to state the obvious.
This is the Catch-22 we are in right now: for our society to survive we must change our culture, which is tricky when our beliefs are molded by the material world of industrial capitalism on fossil hydrocarbon overdrive. We live in a techno-dazzle world, and our outlook consists of an odd combination of ignorance and hubris. For example, just about anyone can understand how a simple tool such as a hoe works, but practically no one comprehends how a smartphone or similarly complex gadget works. And yet such technological wonders keep getting better! So, we find solace in the myth that technology will continually advance and be deployed to solve anything. Try pressing someone about environmental problems and resource constraints, and, in the end, you will usually hear them say something like, “But we have technology,” or “Someone will figure it out.”
This techno-optimism pours forth from experts who envision “sustainable” food production as we wean from fossil fuels, adjust to biodiversity loss, and deal with climate chaos. Need to localize food production? Build skyscrapers designed to grow vegetables. Need to replace crude oil at scale? Build a cellulosic biofuel industry. Need to replace natural gas as a source for synthetic nitrogen fertilizers? Use wind energy and hydrogen instead. Need to apply nitrogen more efficiently on corn? Buy a precision farming package. Want to eat meat but avoid the environmental footprint of doing so? Create fake meat grown in industrial vats. Need to get that excess carbon out of the air? Devise “negative emission technologies.” Most of these are doomed to fail, either completely or at least on the scale proposed. I’m all for imaginative solutions, but it would be nice if some of the imagineers would take into account biophysical realities, rather than engaging in Singularity worship or viewing asteroid mining as the inevitable next step towards a Dyson Sphere civilization.
My report, The Future is Rural: Food System Adaptations to the Great Simplification is a guide to thinking realistically about the forces that will unfold during the 21st century and the pivotal role of food.Energy literacy and an understanding of the relationship between energy and modern technology are paramount to following the logic in this report. A key insight is that renewable energy technologies, particularly solar and wind for electricity generation, don’t help us much when it comes to perpetuating the modern food system.
An important contribution to the discussion of energy systems is the book (and accompanying website) Our Renewable Future: Laying the Path for 100% Clean Energy by Richard Heinberg and David Fridley.In it they provide six reasons why renewable energy systems will not seamlessly power the kind of society we’ve become accustomed to in the age of fossil fuels. These six reasons are:
Intermittency—electricity from solar and wind is not available on demand
The liquid fuels problem—we use more oil than electricity and the unparalleled energy density of liquid fuels is not matched by other sources
Other uses of fossil fuels—fossil hydrocarbons provide a diverse array of chemical feedstocks and can power ultra-high temperature industrial processes that are difficult to substitute with biomass, especially at current scales
Area density of energy collection activities—the area occupied by conventional oil and natural gas wells is tiny relative to the energy these sources supply and doesn’t compete much with alternative land uses
Location—electricity supplied by wind and solar is best used close to where it is captured to avoid transmission losses, and the same is true for bioenergy systems, suggesting that population centers need to be located around available energy sources
Energy quantity—even with massive investments to build-out of renewable energy systems, it will be impossible to replace the quantity of energy currently supplied by oil, coal and natural gas
We can easily apply their schema to the food system, which, in the U.S. and many other places, is just as industrialized and dependent on fossil fuels as any other economic sector.
Almost every step in the industrial food system is so energy-demanding that someone eating a meal in the U.S. ingests only one kilocalorie of food for about every 10 kilocalories spent getting that food to their plate (Figure 1). We have become enthralled by our technology, but perhaps instead we should be aghast at the prodigious amounts of energy our technologies consume. The food system requires more and more energy as the economy replaces expensive human labor with cheaply fueled machines and props up expansive global trade networks. How that excessive energy budget breaks down by activity is informative. The most recent compilation for the U.S. shows the following:
Farm activities and the embedded energy of inputs such as fertilizers account for about 14% of the total.
Processing and packaging, which gives us such convenience and allows food to be shipped globally, is another 25%.
The energy spent by warehouses, grocery stores, cafeterias, and restaurants is about 29%.
The remainder, a whopping 28%, is used by households to go shopping, keep food in refrigerators, and cook.
Transportation is only about 4% of the total, but consider that much of the energy used in the food system, such as processing and warehousing, allows for transportation efficiency.
Analyses of the U.S. food system trends show greater consumption of highly processed foods and increased reliance on appliances, both of which tend to increase energy consumption.
Figure 1. Energy Input and Output in the U.S. Food System.
The Future is Rural report summarizes the complexities of petroleum, natural gas, and electricity dependency and substitution difficulty in the food system. To give a sense of the depth and scale of the challenge, it’s worth examining one segment of the food system—agricultural production—and seeing how the six limiting factors from Our Renewable Future will affect this segment.
Let’s begin with intermittency. Farmers tend to wait for ideal weather conditions and then, as quickly as possible, prepare soil, plant seeds, and harvest crops. Today they rely on liquid fuels (specifically, diesel and gasoline), delivered to on-farm storage tanks that, in turn, fill large fuel tanks on tractors and harvesters. Farmers can’t afford to wait for the sun to shine or the wind to blow and hope that such an event corresponds to the right weather conditions for field activities. Although the intermittency problem could conceivably be solved by battery storage, this is not likely to work for many farm operations because of the low energy density of batteries.
Hence, we have the liquid fuels problem. Although you could theoretically run farms with electric-powered equipment, no technology known or likely to become available has the combination of transportability, storability, and high energy density that hydrocarbon liquid fuels offer. People often believe that because cars can successfully run on electricity, with battery packs allowing hundreds of miles between recharge, this same technology can apply to tractors. However, unlike cars running on smooth roads, typically at steady speeds, tractors are literally dragging steel through rough ground much of the time. Farm equipment tends to operate near its horsepower capacity, whereas a car might work near capacity only when accelerating into traffic. Hydrocarbon liquid fuels are the only known substances with enough energy density to be carried easily onboard a tractor under typical working conditions (e.g., a wide range of temperatures; shaking and bouncing on rough terrain) and to enable work to be performed for many hours in a row (Figure 2).
Figure 2. Energy density (gross heating value) of various storage forms is plotted by weight (MJ/kg) and volume (MJ/l).
An ideal energy storage source has both high gravimetric and volumetric density (upper right corner of graph). Alternatives to fossil fuels tend to be of lower density, making them more burdensome and costlier to use in general. Work performed will be less than gross heating value due to conversion inefficiencies, and efficiency can vary by the kind of work and how well the storage system is suited to it. For example, electric batteries to electric motors is a more efficient conversion (about 90%) than gasoline to internal combustion engines (about 30%). Batteries and other potential storage technologies can improve, but even at theoretical limits they would be many times less energy dense than fossil fuels.
Other uses of fossil fuels include the feedstock for many products used on farms, such as pesticides and fertilizer. Plastics are becoming more abundant on farms as well, including irrigation pipes, weed suppression cloth, and roofing for greenhouses. While there may be ways to replace fossil-fuel-based supplies with renewable ones, such as crop-based feedstocks to make bioplastics and biofuels, these substitutes require using land that could otherwise be used to grow food.
Using land to yield renewable energy supplies also reveals the problem of area density of energy collection activities. In some parts of the country it is common to see an oil well in the middle of a farm field. The oil well may occupy an area the size of a typical home to tap into a sizable underground reservoir. By contrast, if a farm needs to grow biofuel crops to power equipment, the area required to do so is going to be many times larger than the oil well.
Just as fossil fuel deposits are not evenly distributed around the Earth, renewable energy potential varies by location. Furthermore, renewable energy sources are best used near their place of capture and storage. Farms tend to be located where soil and climate conditions are ideal. Some farms will be fortunately situated where great soils and rainfall patterns coincide with optimum solar radiation, consistent winds, or hydroelectric potential. But we have already reviewed why electricity will have a limited role in powering farms, even if it happens to be convenient to produce. The more certain renewable energy source on farms will be biomass. Farms of the future will need to make do with wood, straw, other crop residues, and extracted sugars or oils.
The energy quantity available to our society when powered by biomass plus renewable electricity will be far less that what we are accustomed to now. On the farm this implies finding ways to reduce energy use, both directly and embodied and equipment and products. Going forward we may have less frequent or intense tillage, less irrigation, and fewer fertilizer and pesticide applications.
I don’t mean to imply that all troubles with agriculture and the food system began with the Industrial Revolution, and energy issues extend well beyond the farm. Even before tractors were invented, 19th century European and North American farmers became dependent on far-flung sources of guano to prop up depleted soils back home, with typical geopolitical maneuvers and tensions as a result. With the advent of the Haber-Bosch process that uses natural gas to make nitrogen fertilizer, discussion of potential resource constraints today tends to concentrate on phosphate rock and how much is left to be mined in different parts of the world. Both nitrogen and phosphorus supplies are reliant on abundant fossil fuels either as a feedstock or to power heavy mining and transport equipment, so ultimately the most crucial input to our current food system is the suite of products from the fossil hydrocarbon industry.
If the techno-utopian future does not arrive and fossil hydrocarbon extraction no longer powers the economy, then what kind of food system are we looking at? The Future is Rural delves into this question, giving a tour of concepts and lessons from history, geography, agronomy, soil science, ecology, sustainability, and resilience thinking. It is certainly possible for agriculture to conserve soil, avoid extravagant energy use, and protect the natural environment, including the climate and other species that live with us on Earth.
Technical fixes that will work must use less energy than we are accustomed to, and seeing the possibilities requires becoming steeped in biology and appreciating the talents of other species of plants, animals, fungi and microbes. To wean ourselves from oil and natural gas, we can manage the agroecosystem with biological tools, made of cellulose and flesh, instead of industrial-mechanical ones, made of steel and petrochemicals.
Imagining and developing these biological tools could usefully occupy the minds of millions of people in places like the U.S., where the population has become disconnected from the land that feeds them. That would be a hopeful use of human creativity. The photograph below offers a simple example. It shows a field of sheep grazing a pasture in the early spring. This pasture will be tilled and then planted in an annual crop once the soil dries enough. Through grazing, the sheep keep the sod cropped close to the ground so the tractor will have much less plant biomass to handle, reducing the time and energy needed to prepare the soil for planting. By contrast, the field in the distance was sprayed with an herbicide a month ago for the same reason, i.e., reducing the plant biomass prior to tillage, which is the common practice nowadays.
Take this one example and then multiply it across a vast collection of daily activities and what do you eventually get? A society reorganized around the land, a diversity of symbiotic species, and solar energy income. Relatively few have pondered what the transformations in energy and agriculture mean or how we can go through them gracefully. Will we change the stories we tell ourselves today about what we value and what is meant by the good life? Will this new narrative translate into new behaviors that help our descendants survive in the future? Or will we keep peddling the progress myth, fooling ourselves and remaining ignorant about energy, extracting the last drops of ancient sunlight as our infrastructure and living systems fray around us? Unfortunately, history suggest the latter is most likely (but not certain!), and that new cultures with myths appropriate to new ways of living arise after the old ones die off and become archeological grave sites. I don’t want that outcome and, at the very least, plan to have fun working on the former option.
Navigating energy descent will require rediscovering a land ethic that resets social norms to help us restore and protect the places we love. The process of discovery will be fraught with uncertainty and unexpected changes. We shouldn’t expect to have all the answers or to foresee a clear path ahead before taking this journey. But we need to get moving anyway, and we need to do it together.
 Day, John and Charles Hall, America’s Most Sustainable Cities and Regions: Surviving the 21st Century Megatrends, (Springer, 2016).
 William Catton termed this “Cargoism” after the quasi-religions that developed in parts of the South Pacific during WWII. More specifically, here is a short video that reviews the current fashions in agriculture and food technologies: “The Future of Farming & Agriculture,” (TheDailyConversation, YouTube: 2017), https://www.youtube.com/watch?v=Qmla9NLFBvU.
 Heinberg, Richard, There’s No App for That (Corvallis, OR: Post Carbon Institute, 2017), http://www.postcarbon.org/publications/theres-no-app-for-that/.
 Pimbert, Michael and Colin Anderson, “The battle for the future of farming: what you need to know,” (The Conversation, Nov. 21, 2018), https://theconversation.com/the-battle-for-the-future-of-farming-what-you-need-to-know-106805.
 See for example, Kowitt, Beth, “Silicon Valley and the Search for Meatless Meat” (Fortune, 2017), http://fortune.com/2017/12/19/silicon-valley-meatless-meat/.
 European Academies Science Advisory Council, Negative emission technologies: What role in meeting Paris Agreement targets? (EASAC policy report 35, February 2018), https://easac.eu/press-releases/details/negative-emission-technologies-will-not-compensate-for-inadequate-climate-change-mitigation-efforts/.
 Heinberg, Richard, and David Fridley. Our Renewable Future: Laying the Path for 100% Clean Energy. (Washington: Island Press, 2016), http://ourrenewablefuture.org/.
 Let’s do some simple math. The world economy uses around 100 billion barrel of oil equivalents a year. A barrel of oil equals around 4-10 years of human labor. This means a human population of nearly 8 billion is employing the labor equivalent of 400 billion to a 1 trillion “energy slaves.” This is the power of ancient sunlight (and some nuclear fission), and it is impossible for renewables using contemporary solar flows to provide nearly the same scale of power.
 Center for Sustainable Systems, “U.S. Food System Factsheet,” (University of Michigan, 2017), Pub. No. CSS01-06.
 Canning, Patrick, Ainsley Charles, Sonya Huang, Karen R. Polenske, and Arnold Waters, “Energy Use in the U.S. Food System,” Economic Research Report Number 94 (United States Department of Agriculture, Economic Research Service, 2010).
 Center for Sustainable Systems, “U.S. Food System Factsheet,” Pub. No. CSS01-06, (University of Michigan, 2017).