Global food demand is on the verge of rising rapidly. One driver of demand, of course, is the continued expansion of the population. As noted by the UN Population Division, the world’s population will exceed 11.2 billion by the year 2100, meaningfully above the current estimate of 7.4 billion. This means that between now and the end of the century, we will, on average, add 125,000 people to the planet’s population every day. More mouths, more food.
And what people are putting into their mouths is changing. As incomes have risen and the global middle class has grown, demand for animal protein is rising. But as food writer Michael Pollan notes, “You are what you eat eats.” Before you can consume your steak, the cow itself had to eat. As did the pig that provided your bacon… and the chicken, your drumstick. In fact, it’s estimated that livestock themselves eat a third or more of the world’s food. Richer planet, more calories.
Apologies to animal lovers that may find my analogy distasteful, but one way to think of livestock is as a converter of lower value raw materials (feed) into higher value outputs (protein). Consider beef. A cow, according to Tyson Foods, must consume somewhere between 7 and 9 pounds of inputs to produce 1 pound of output (a feed conversion ratio of about 8). Not very efficient! Meanwhile, the ratio for pigs is slightly above 3 and for chickens is around 2.2.
The combination of more mouths to feed and more protein in each mouth threatens to generate exponential demand growth for food. While this dynamic is alarming unto itself, it’s even more concerning when we factor in the headwinds of climate change that will likely hurt agricultural yields. Lester Brown of the Earth Policy Institute has noted that a 1 degree Celsius rise in average temperatures has the potential to reduce agricultural yields by 10 percent. Warmer planet, less food.
And while climate change can affect food supplies, meat production is proving equally capable of affecting the climate. Note, for instance, that livestock are currently responsible for between 35 and 50 percent of greenhouse gas emissions, largely by way of their own emissions (a fact that delights 6-year-old boys). But the total also includes carbon associated with energy used for transportation, livestock respiration and the processing and handling of meat. Incorporating these factors leads to some startling conclusions. A cow, for instance, produces up to 30 pounds of carbon for each pound of edible meat; a pig, almost 6. Animals also need water, and lots of it. One kilogram of edible chicken uses 4,300 liters of freshwater, while a kilogram of pork uses around 6,000. Beef? 15,400 liters per kilogram of edible meat! More people, richer people, changing climate.
These dynamics suggest our current food system will struggle to keep up with the growing appetite of a crowded and warming planet. Food riots and unrest risks are rising. What, if anything, can be done?
Technology does offer some hope. Genetic technology has tremendous potential to improve agricultural productivity and lab-grown meat may alleviate some of the environmental footprint from livestock. But there’s an under-exploited strategy at our fingertips that deserves much greater attention. We could shift the mix of proteins the world consumes towards more fish. Fish as a means to fight famine and combat climate change? Yes, fish.
The bottom line is fish are more efficient protein producers that leave a smaller carbon wake and consume less fresh water. Shifting diets toward fish has the potential to meaningfully reduce the growing pressures on the global food system.
For ease of comparison, let’s take a look at farm-raised Atlantic salmon. To begin, the fish has a feed conversion ratio of 1.2, meaning it needs significantly less food to produce edible meat. It also uses less fresh water and produces fewer greenhouse gases. According to Marine Harvest, 1 kilogram of salmon uses 2,000 liters of water and produces 2.9 kilograms of carbon dioxide equivalent, approximately one-sixth that of beef.
To be fair, farming fish is not entirely sustainable either. As noted in “The Perfect Protein,” a book by Oceana CEO Andy Sharpless, poorly managed aquaculture has been quite harmful to ocean ecosystems. Specifically, he describes the rapid rise of Chile’s salmon industry and how it led to massive disease outbreaks in 2008 and concentrated fish pens generated dead zones as fish waste accumulated. And scientists from the Scripps Institution of Oceanography have identified varying levels of toxic pollutants in almost every fish they studied.
Fish farming may not be the perfect long-term solution to address the world’s forthcoming boom in animal protein demand, but it might buy us much-needed time to build out the infrastructure needed to safely transport food from where it is to where it’s needed and to reduce waste. It also offers the prospect of generating new local economies in regions of the world — such as Africa — that have yet to fully exploit the possibilities of aquaculture.
For most of human history, life was characterized by scarcity. Yet today we live in a world of abundance. Think about the fact that there are more obese people than hungry people in the world today. But as the world’s population bulges and diets shift, short-term wants will generate cross-currents against long-term needs. The future has always been uncertain, but in this case, the future looks pretty fishy to me.