The University of Manitoba’s Vaclav Smil has calculated that if affluent consumers lowered their intake of these foods by 15–35 percent, it would save between 5 and 15 percent of the phosphorus now used to grow the grain crops that feed the animals. In view of the looming shortages of land, water, and energy and the impact of climate change, however, it is important to recognize that traditional methods of farming used for centuries may not be able to produce food for all humanity sustainably into the future, and certainly not in all regions of the world. As a result we may have to develop alternative food- production systems that make far less use of land, water, and energy and rely instead on recycled urban nutrients, smart technology, and human labor.
Such systems already exist. Scientists have long grown cultures of plant and animal cells and microbes in the laboratory, and this procedure is capable of being scaled up to produce food in large vessels known as bioreactors. Just add warmth, water, and the right nutrients and you can produce edible, nutritious food by the ton from microbial, vegetable, or fungal cultures. Although this may sound fairly distasteful to the gourmet, one should never forget that fine wines, cheeses, salamis, and beers are all the products of microbial pro cesses.
In any case, many of today’s savory snacks— especially sausage (into whose mysteries few dare to inquire) and surimi seafood— are made from recycled food “wastes,” so this is merely an extension of the transformations the food manufacturing industry already performs. The chief argument in favor of this form of food production is its ability to convert hitherto wasted water and nutrients into a healthy, even interesting, diet with a minimum of energy, transportation, and other inputs. Such pro cesses have long been contemplated for supporting colonies on the moon or Mars, but it may transpire that they will be needed in order to sustain spaceship Earth a little sooner.
A tantalizing new form of food production is “artificial photosynthesis”—artificially mimicking what plants do naturally, which is use sunlight to convert water and carbon dioxide into sugars and carbohydrates. Teams of scientists around the world are already working on this challenge, which is primarily seen as a way of producing sustainable energy but can also, potentially, be used to produce sustainable food, using as a feedstock the carbon dioxide emissions from power stations or even vehicles.
Although the idea of eating food made from your car’s exhaust sounds unappetizing, it is no more so than eating the recycled nutrients from human waste, which we have been doing since the dawn of civilization. At least in theory, artificial photosynthesis offers the potential to produce nutritious food in large volumes from a limited area and by reusing waste carbon emissions.
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