Ch. 2: Understanding Food Production (How the World Really Works)

Eating Fossil Fuels

• Securing food is an existential imperative for all species. Human ancestors evolved key physical traits like erect posture, bipedalism, and large brains, enabling them to scavenge, gather, and hunt more efficiently.
• Early human tools were basic and mainly used for butchering. Advanced tools like spears, nets, and bows expanded the range of species they could hunt.
• Transition to agriculture provided a more stable, but not necessarily more nutritious, food supply. Foraging in arid environments required vast areas.
• Population density increased in fertile regions and among coastal groups with access to fish and aquatic mammals. Early agriculture increased carrying capacity but reduced dietary variety.
• Despite the challenges, technological advances have reduced global malnutrition significantly over the past few generations.
• Fossil fuels and electricity have become indispensable in modern food production, both directly and indirectly.
• Agriculture is fundamentally powered by solar radiation, but the intensification of crop and animal production relies heavily on non-renewable energy sources.
• The last two centuries have seen an epochal shift in food production efficiency, initially marginal but becoming significant in the early 20th century.
• Advances in food production are not confined to any one region but have occurred globally, albeit at different times.

Three valleys, two centuries apart

• In 1801, Genesee Valley, New York, wheat farming methods were similar to ancient practices. It required 150 hours of human labor and 70 ox-hours per hectare, yielding one ton of grain per hectare.
• By 1901, in the Red River Valley, North Dakota, farming became more mechanized with horses and steam engines. Labor time reduced to 22 hours per hectare, but yields remained at one ton per hectare. A quarter of American farmland was used for animal fodder.
• The energy sources transitioned from purely solar to a mix of solar and non-renewable, mainly coal. Steel became crucial for machinery, and inorganic fertilizers began to be used.
• In 2021, in Kansas, farms are much larger but operated by fewer people due to mechanization. Human labor reduced to less than two hours per hectare, with yields at 3.5 tons per hectare.
• The time required to produce a kilogram of wheat reduced from 10 minutes in 1801 to less than two seconds in 2021, representing a monumental gain in productivity.
• The shift from labor-intensive to mechanized farming has been critical for societal advances, allowing people to move from agriculture to other sectors.
• The transformation was not unique to the U.S.; similar productivity gains have been seen in rice farming in China and India.
• The road to modern civilization began with advancements like steel plows and inorganic fertilizers, enabling a well-fed population and freeing labor for other sectors.

What goes in

• Preindustrial farming relied solely on solar energy, human and animal labor, and simple tools. Modern farming, while still dependent on solar energy, also relies heavily on fossil fuels and electricity.
• Machines consume direct fossil energy as diesel or gasoline for various field operations, crop processing, and transport. Indirect energy is used in the production of these machines, including materials like steel, rubber, plastics, and electronics.
• Energy consumption for the production of agrochemicals like fungicides, insecticides, and herbicides dwarfs that of machinery. These chemicals require high energy but are used in small quantities.
• Fertilizers, supplying essential macronutrients like nitrogen, phosphorus, and potassium, require less energy per unit but are needed in large quantities for high yields.
• Nitrogen is a critical element in farming, essential for cell growth and photosynthesis. It exists abundantly in the atmosphere but is non-reactive, requiring specific processes to make it available to crops.
• Natural nitrogen fixation is limited, occurring through processes like lightning and bacteria associated with the roots of leguminous plants. This is insufficient for global food production needs.
• In traditional farming, human and animal wastes were laboriously collected and applied to fields to enrich soil with nitrogen, consuming up to a third of all labor in farming.
• The nitrogen barrier was broken in the 19th century with Chilean nitrates and decisively with the invention of ammonia synthesis by Fritz Haber in 1909. This enabled the Green Revolution in the 1960s, with high-yielding crop varieties requiring synthetic nitrogenous fertilizers.
• Since the 1970s, the synthesis of nitrogenous fertilizers has been the most significant among agricultural energy subsidies. Detailed energy accounts reveal that common foodstuffs like bread, chicken, and tomatoes rely heavily on fossil fuel subsidies.
• For the foreseeable future, global food production remains dependent on fossil fuels, making it a critical factor in feeding the world’s nearly 8 billion people.

The energy costs of bread, chicken, and tomatoes

• The energy subsidy for various types of bread has been studied extensively. Efficient American production of wheat for bread requires about 4 megajoules per kilogram of grain, which translates roughly to 100 milliliters of diesel fuel per kilogram of wheat.
• The energy required for producing a 1-kilogram sourdough loaf, from growing grain to baking, is equivalent to at least 250 milliliters of diesel fuel. Standard baguettes and large German Bauernbrot have their own energy equivalents, measured in tablespoons and cups of diesel fuel respectively.
• The shift from local bakeries to large-scale baking operations increases transportation costs, potentially raising the energy cost to as high as 600 milliliters of diesel fuel per kilogram of bread.
• In poultry farming, the feed-to-meat ratio has improved considerably over the decades, making chicken a more energy-efficient source of protein compared to beef or pork. Energy costs for chicken can range from 150 to 750 milliliters of diesel fuel per kilogram of edible meat.
• Further energy costs arise from intercontinental trade in feedstuffs, as well as the energy required for poultry housing, waste removal, and the entire supply chain. The total energy requirement can range from 200 milliliters to 1 liter of diesel fuel per kilogram of chicken meat.
• The energy subsidy for vegetables, such as tomatoes, is surprisingly high. For instance, tomatoes grown in heated multi-tunnel greenhouses in Spain require more than 500 milliliters of diesel fuel per kilogram. Tomatoes are also heavily fertilized, requiring up to 10 times the nitrogen used for grain corn.
• The transport of produce, like tomatoes from Spain to Scandinavia, adds nearly 130 milliliters of diesel fuel per kilogram, making the total embedded production and transportation energy cost stunningly high—around 650 milliliters of diesel fuel per kilogram.
• Despite the common perception that plant-based diets like veganism have a lower energy and environmental footprint, many popular vegetables have a substantial fossil fuel pedigree, challenging this notion.
• The energy costs for both meat and plant-based foods are underlined by the crucial role of fossil fuels at every step of the production and distribution process, emphasizing the interconnectedness of our food system with energy resources.

Diesel oil behind seafood

• Hunting on land has largely become a marginal source of nutrition in affluent societies, but marine hunting or fishing is more prevalent than ever, involving everything from small boats to large floating factories.
• Capturing seafood is one of the most energy-intensive food provisions. While easier-to-catch pelagic species like sardines or mackerel require less energy (around 100 mL/kg of diesel fuel), the average energy expenditure for all seafood is shockingly high—700 mL/kg. For some species like wild shrimp and lobsters, it can go up to more than 10 liters/kg.
• Aquaculture has not necessarily offered a more energy-efficient alternative, especially for carnivorous species like salmon, sea bass, and tuna. These species require protein-rich fish meals and fish oil, derived from wild-caught smaller species, making their energy costs similar to their wild counterparts—around 2–2.5 liters of diesel fuel per kilogram.
• Herbivorous fish in aquaculture, like different species of Chinese carp, are more energy-efficient, with costs typically less than 300 mL/kg. However, these are not popular culinary choices in many Western countries, and the growing global demand for sushi has increased the fishing pressures on already endangered species like tuna.
• The energy-intensive nature of our modern food supply system underscores our deep dependence on fossil fuels. This is a reality that is often overlooked by advocates of rapid decarbonization.
• Whether it’s grains, poultry, vegetables, or seafood, the energy costs associated with each category of food reveal a stark truth: our current food system is intrinsically tied to fossil fuel usage, making any quick transition to a low-carbon system extremely challenging.
• The intricate web of energy subsidies in our food supply—from the diesel fuel used in tractors and fishing boats to the electricity that powers greenhouses and poultry houses—highlights the grand scale and complexity of our dependence on fossil fuels. The decarbonization of our food supply is not merely a matter of will or innovation but entails a comprehensive rethinking of entrenched systems and practices.

Fuel and food

The modern food system, often perceived as a marvel of efficiency, is paradoxically a prodigious consumer of energy, much of it derived from fossil fuels. From the dawn of the 19th century, when agriculture was largely a manual affair, to our contemporary world of mechanized farming and industrial-scale fishing, the energy subsidy into food production has surged dramatically. While the global population increased less than fourfold and farmland grew by about 40 percent from 1900 to 2000, anthropogenic energy subsidies in agriculture burgeoned 90-fold.

It is instructive to note that although agriculture’s share of global energy consumption seems modest—only about 4 percent—it serves as a testament to the principle that small inputs can have disproportionately large consequences. This is a notion that prevails in complex systems; consider the minuscule amounts of essential vitamins and minerals that regulate the human body. The seemingly insignificant percentage is thus not a sign of efficiency but rather an indication of how much we have mechanized the natural processes, targeting every stage where human intervention could artificially boost yield, from fertilization and irrigation to pest control and timely harvesting.

However, this 4 percent accounts only for primary food production. When we expand the scope to include food processing, marketing, packaging, transportation, and household storage and preparation, the energy consumption becomes far more substantial. In the United States, for example, this more comprehensive approach reveals that nearly 20 percent of the nation’s energy supply is devoted to the food system. This escalation is driven by factors such as increased transportation needs due to consolidated production, growing food import dependency, and changes in eating habits, including more meals consumed outside the home and a rising demand for pre-prepared foods.

The imperative to reconsider our food production practices is pressing, not merely for their contribution to greenhouse gas emissions but also for a plethora of other environmental impacts, including biodiversity loss and the creation of aquatic dead zones. Furthermore, the system’s built-in inefficiency is evidenced by the scale of food waste it generates. Indeed, there are cogent ethical, environmental, and economic reasons to reevaluate and