Let me start with the following principle: “Energy is the only universal currency: one of its many forms must be transformed to accomplish anything.” Economies are nothing more than complex systems set up to carry out such transformations, and all economically significant energy conversions have (often highly undesirable) environmental impacts. Consequently, as far as the biosphere is concerned, the best anthropogenic energy conversions are those that never occur: no emissions of gases (whether greenhouse gases or acidifiers), no generation of solid or liquid waste, no destruction of ecosystems. The best way to do this has been to convert energies with higher efficiencies: without their widespread adoption (whether in large diesel and jet engines, combined cycle gas turbines, light-emitting diodes, steel or in the synthesis of ammonia) ) we would need to convert a much greater quantity of primary energy, with all the ensuing environmental impacts.
Conversely, what could be more wasteful, more undesirable, and more irrational than denying much of these conversion gains by wasting them? Yet this is precisely what continues to happen – and at indefensibly high levels – with all end uses of energy. Buildings consume about a fifth of all global energy, but due to inadequate wall and ceiling insulation, single-glazed windows and poor ventilation, they waste at least a fifth to a third of it, compared to interior spaces well designed. A typical SUV today is twice as massive as a common pre-SUV vehicle and requires at least a third more energy to perform the same task.
The most offensive of these wasteful practices is our food production. The modern food system (from the energy used in the selection of new varieties, in the synthesis of fertilizers and other agricultural chemicals and in the production of agricultural machinery to the energy used in harvesting, transport, processing, storage, sale retail and cooking) absorbs almost 20% of primary fuels and electricity and we waste up to 40% of all food produced. Some food waste is unavoidable. The prevalent food waste, however, is more than indefensible. In many ways it is criminal.
Fighting it is difficult for many reasons. First, there are many ways to waste food: from losses in the field to spoilage in warehouses, from perishable seasonal surpluses to maintaining “perfect” displays in stores, from oversized portions when eating out to the decline of home cooking.
Second, food today travels very far before reaching consumers: the average distance a typical food item travels is between 1,500 and 2,500 miles before it is purchased.
Third, the cost remains too low compared to other expenses. Despite recent increases in food prices, families today spend only about 11% of their disposable income on food (in 1960 it was about 20%). Spending on food outside the home (generally more expensive than consumption at home) now represents more than half of the total. And finally, as consumers, we have too much food choice available: just consider that the average American supermarket now sells more than 30,000 food products.
Apparently our society is quite happy to waste 40% of the nearly 20% of all energy it spends on food. In 2025, unfortunately, this shocking level of waste will no longer receive attention. In fact, the situation will only get worse. As we continue to invest billions in the search for energy “solutions” – ranging from new nuclear reactors (even fusion!) to green hydrogen, all with their own environmental burden – in 2025, we will continue to fail to address the enormous waste of food that required so much fuel and electricity to produce.