Reducing wasted food can also lower the 10:1 ratio of energy used to food eaten. An egregious 25 percent or more of the food grown is wasted annually. That massive amount represents 2.5 percent of annual U.S. energy consumption—more energy than all the ethanol produced in 2011 in the U.S. and more than the energy that will be produced in 2030 from lifting drilling restrictions today on the outer continental shelf. Simply decreasing the amount of food we throw away might reduce energy consumption and greenhouse gas emissions more over the next decade or two than many of the expensive or controversial energy supply policies that have been proposed.
Many methods of reducing food waste can begin tomorrow. We can invest in diagnostics that monitor food spoilage instead of using the crude date-based labeling system that has been in place for several decades. One example is temperature- and time-sensitive inks on food packaging that cause labels to change color if the food has been exposed to the wrong temperature for too long. Start-up companies produce these labels, which could spare a lot of food that is unnecessarily thrown away by stores that are worried about making their customers sick. The labels could indeed also prevent a lot of illnesses induced by spoiled food. Requiring companies to keep track of the temperatures that food has been exposed to—in addition to how long the food has been packaged—might give retailers and consumers better information about the risks of spoilage.
Different attitudes and dietary choices can help, too. Restaurants can stop serving mammoth portions, and consumers can stop bragging about their conquests at all-you-can-eat buffets. More extra food can be kept and eaten as leftovers. We can shift our diets to replace at least some of our energy-intensive meats with less energy-intensive fruits, nuts, vegetables, beans and grains. These behaviors do not require invention; they just require new thinking. Many of them end up saving consumers money as well. Having meatless Fridays or veggie Mondays might start to get us there.
As the original green revolution showed, large-scale changes can be implemented relatively quickly over just a few decades. The changes can be dramatic, achieving outcomes far better than anticipated. Yet surprises can arise, too: years of abundant food production have increased the incidence of obesity and aggravated climate change. Technology alone is not enough; even with the original green revolution, hunger has not been solved. A global approach to reducing the energy waste in food that incorporates new behaviors, attitudes and policies will be critical to widespread success. There is no reason to think this new green revolution will be any different.