As rural masses migrate to urban areas, populations grow, and people work toward better living standards, global food system sustainability pays a high price, according to a new analysis spanning low- to high-income countries. The study, which was published April 3 in the scientific journal PLOS ONE, shows that only one major global driver - the increase in international trade flows - appears to have a net positive effect on global food systems sustainability. All other major drivers (population growth, urbanization, lifestyle change, and changes in land use) seem to have negative effects.
"Trade seems to be good for food systems - but only up to a point," said Steven Prager, a study co-author from the Alliance of Bioversity International and CIAT. "Beyond a certain level, the positive effect of trade tends to plateau. High-income countries simply don't continue to benefit."
In the context of the COVID-19 pandemic, the immediate focus of the research community is, correctly, on human health. But global disturbances sparked by the pandemic also reveal how fragile our global food systems are.
In those conditions, "Understanding what drives our food systems and how we can measure or monitor them becomes vital if we want to give policymakers better tools for making food systems more sustainable and more resilient to local or global shocks such as the extreme one we are experiencing today," said Christophe Béné, the study's lead author.
Helping policymakers "understand the dynamic of our food systems"
The study builds on a global map of food system sustainability published in November in Scientific Data, a Nature journal. That study showed that high-income countries tend to have a higher level of food system sustainability (despite all the junk food they consume) than lower-income countries. Those findings were one of the motivations behind the new study. Its authors wanted to understand what drives those different levels of sustainability and what can be done to improve the situation.
"Local and global food systems are simply reflecting the ways the world is evolving," said Jessica Fanzo, a co-author and Associate Professor of Global Food & Agricultural Policy and Ethics at the Johns Hopkins School of Advanced International Studies.
"Some of the key drivers of the global demographic transition that the world is experiencing right now are also heavily impacting our food systems," said Fanzo, who was also the team leader on the 2017 report by the High Level Panel of Experts on Food Security and Nutrition, an initiative of the Food and Agriculture Organization of the United Nations.
The problem is that all these drivers, so far, have had a negative impact on food systems and these drivers are very difficult to control.
"It would be very difficult to prevent people from migrating to cities or from embracing new lifestyles as their income rises," said Fanzo. "We need therefore to find very rapidly the way to reverse or mitigate the consequences of these trends."
Though the results of the study point to some serious challenges ahead, they also offer some initial indications for policymakers about where to direct effort and investment to improve the long-term sustainability of our food systems.