A recent paper, “The water-land-food-nexus of first-generation biofuels,” looked at if and how the production of biofuels is affecting global food security. Looking at the links between overall human appropriation of land and water resources, the study found that biofuels rely on about 2 to 3 percent of the global water and land used for agriculture and this could feed about 30 percent of the malnourished population.
Paolo D’Odorico, with the Department of Environmental Sciences with the University of Virginia, explained that the study looked at globally how much water and land it takes to produce biofuels from first generation crops such as corn and soybeans, and that he felt the study was important because there has been a lot in the media about the use of land and water resources for bioenergy and for food.
“We have tried to link the use of land, water, and bioenergy with food, and then we tried to look at where biofuels are coming from, and we have this comparison between areas of bioenergy consumption and areas of production of biofuel crops, which allows us to investigate the associated impact on food security,” says D’Odorico. “We have been trying to quantify to what expense the production of biofuels is coming locally versus through trade, and what is the impact on the environment by producing this energy.”
The study found that in 2013 about 65 million tons of ethanol and 21 million tons of biodiesel were consumed globally. Based on this number, biofuel production consumed 216 billion m3 of water, or about 3 percent of the global water consumption for food production. D’Odorico says while the water footprint of both biofuels are comparable the land footprint for biodiesel production is more than 100 percent greater than that of ethanol. He cautions that the values vary greatly depending on geographic location and the crop.
Taking into account the animal feed produced as a bi-product of biofuel production, the study found the agricultural resources used to meet ethanol demand in the top 14 consuming countries could feed 200 million people. The crops used for the study included maize, sugarcane, wheat, sugarbeet, and sorghum. For biodiesel, the study primarily looked at rapeseed, soybean, and palm oil and found that about 70 million people could be fed, looking at the top 29 consuming countries.
The research team determined the number of people who fed through per capita calorie requirements and the caloric content of the crop and concluded that while the direct impact of biodiesel on food security is similar to that of bioethanol, when evaluated in terms of the number of people who could be fed per unit of bioenergy, the impact of bioethanol on food security is greater.
So how were the calories per person determined and thus food security?
“When we look at biofuel crops being used in a diet, we want to see how many people can be fed by these crops, and this includes their use as both plant food and animal food,” D’Odorico explains. “Animal food requires plant food in order to be produced. We know that five calories of seed are required to produce one calorie of animal food, like milk, eggs, or meat. For the food and feed that turns into meat/animal products, we used a conversion ratio between calories of feed used and the calories of the final animal product. So if we have a 2,000 kilocalorie diet of which 600 kilocalories comes from animal products, we can get the total amount of food and feed together that corresponds to the value. And so this is what we replace with biofuels.”