A new study by researchers from Norway, Austria, and Switzerland has found that while animal-based food production was responsible for almost 60% of the energy footprint of agriculture from 2015-2019, it provided just 18% of global caloric intake during the same period.
In addition, the energy generated by animal-based food production is largely driven by fossil fuels, the study noted, although moves are underway to adopt more green energy practices.
‘Hugely inefficient’
“But what’s the solution for agriculture?” commented Edgar Hertwich, professor of industrial ecology at Norwegian University of Science and Technology (NTNU). “Animal husbandry is hugely inefficient. We first produce edible products and then we feed these edible products to animals to get a much smaller fraction of the calories back.”
The study sought to determine the global food system’s energy efficiency by calculating the energy return on energy investment (EROI), which compares the energy invested in food production to the energy provided by the food in the form of calories.
Energy efficiency
While the energy efficiency of global food systems generally improved between 1995 and 2019 (from an EROI of 0.68 to 0.91), this still meant that for every calorie of food produced, 10% more energy was required.
Where food systems were less industrialised, such as in countries in East and West Africa and South and Southeast Asia, better energy returns were achieved (above 1), with West Africa being the top performer with an EROI of 2.70.
“That the energy efficiency of the food systems that high-income regions rely on has increased in the last couple of decades was a positive surprise,” noted Kajwan Rasul, a researcher at NTNU’s Industrial Ecology Programme, who led the research. “However, that could be due to a shift to a more calorie-intense diet or an increased reliance on imports from regions that have better conditions to produce food in a more energy-efficient way.”
Elsewhere, the researchers note that inefficiencies in food production are not only a climate issue but also present a potential food security concern – with agricultural systems heavily reliant on fossil fuels, international events, such as war or conflict, can threaten that security.
Agricultural systems that rely on fossil fuels “turn the question of food security into a question of energy security,” Rasul and his co-authors noted.
The full study was published in PNAS Nexus, a journal of the National Academy of Sciences. Read more here.
