The socioeconomic effects of COVID-19 will likely cause another severe production crisis in the coffee industry, finds a new study co-authored by University of Arizona researchers.

Coffee is one of the most widely traded agricultural commodities in the world, supporting the livelihoods of about 100 million people globally, especially in low-income countries. But the industry has long struggled with many stresses, including institutional reforms, market price volatilities, extreme climate events, plant diseases and pests. Over the past year, COVID-19 has become a new threat to the coffee industry by acting as potential trigger for renewed epidemics of coffee leaf rust – the most severe coffee plant disease in the world.

"The coffee production system was teetering before COVID," said Zackry Guido, assistant research professor in the Arizona Institutes for Resilience and co-author of the new study, which is published in Proceedings of the National Academy of Sciences. "I fear that changes from COVID that do not address root causes of vulnerability will be one shock too many for many of the smallholders. A better understanding of the fragility of the production chain is needed."

"Any major impacts in the global coffee industry will have serious implications for millions of people across the globe, including the coffee retail market here in the United States," said lead study author Kevon Rhiney, an assistant professor in the Department of Geography at Rutgers University.

The researchers drew on recent studies of coffee leaf rust, a fungal disease that has severely impacted several countries across Latin America and the Caribbean over the last decade. They looked at how past outbreaks have been linked to poor crops and investment in coffee farms, and how COVID-19's impacts on labor, unemployment, stay-at-home orders and international border policies could affect investments in coffee plants and in turn create conditions favorable for future shocks.

The researchers concluded that COVID-19's socioeconomic disruptions are likely to drive the coffee industry into another severe production crisis.

"Our paper shows that coffee leaf rust outbreaks are complex socioeconomic phenomena, and that managing the disease also involves a blend of scientific and social solutions," Rhiney said. "There is no 'magic bullet' that will simply make this problem disappear. Addressing coffee leaf rust involves more than just getting outbreaks under control; it also involves safeguarding farmers' livelihoods in order to build resilience to future shocks."

The researchers said the challenges from coffee leaf rust reflect a trend in disease-driven collapses in recent years in major global commodity markets such as banana and cocoa, where large-scale farming of single crops and homogenization of plant traits make it easy for diseases to emerge and spread.

They conclude that the COVID-19 pandemic highlights the interconnectedness of the global coffee system as both a vulnerability and a source of strength.

"The spread of COVID-19 and coffee leaf rust both reveal the systemic weaknesses and inequalities of our social and economic systems," Rhiney said.

"Small-scale coffee farmers generate vast wealth across the globe, but are themselves are highly vulnerable. They exemplify an extreme imbalance," Guido added. "I feel incredibly fortunate to study coffee. The more I've learned about coffee and the more I've worked with people who involved in its production and scholarship, the more energized I am to play a small role in making it a more sustainable livelihood."

The study also included researchers from the University of Hawaii at Hilo, CIRAD, Santa Clara University, Purdue University West Lafayette and the University of Exeter.