Global food production at risk as rising temperatures threaten farmers’ physical ability to work, new study finds

The future of global food production is under threat as rising temperatures will impact farmers’ physical ability to work, a new study has found.

The study, which brings together Loughborough University and universities in Australia and the United States, predicts that by the end of the century, labor productivity could fall by up to 40% in key food-producing regions such as Pakistan and India.

While other important agricultural regions of Southeast and South Asia, West and Central Africa as well as northern South America are expected to see their physical labor capacity reduced to 70%.

“Assessments consistently conclude that climate change will reduce crop yields, thereby worsening food security problems,” says study leader Professor Gerald Nelson of the University of Illinois.

“But it’s not just crops and livestock that are affected. The agricultural workers who plant, plow and harvest much of the food we need will also suffer from heat exposure, reducing their ability to undertake work in the fields.”

Published in the journal Biology of global changeThe study, titled “Global reductions in manual agricultural labor capacity due to climate change”, involved the use of computer models to predict physical labor capacity (PWC) – defined as “the work capacity of a individual compared to an environment without any heat stress” – according to different predicted climate change scenarios.

The models, developed by Loughborough University, are based on data from more than 700 heat stress tests, which involved observing people working in a wide range of temperatures and humidity, and in different weather conditions, particularly sunshine and wind.

The maximum work capacity achievable by individuals in a cool climate was used as a reference for the study, representing 100% physical work capacity.

Capacity reductions mean people are limited in what they can physically do, even if they are motivated to work. This may result in farmers needing additional workers to do the same work or, if these are not available, reducing the size of their crops.

Agricultural workers are already feeling the pressure, the study finds, with half of the world’s cropland farmers working below 86% capacity under climatic conditions of the “recent past” (1991-2010).

As a next step, the study examined potential adaptations to mitigate the impact of climate change on agricultural workers.

Shifting to working at night or in the shade to reduce direct solar radiation has been shown to result in a 5-10% improvement in worker productivity.

A second option being explored is increasing the global use of machinery and mechanical equipment, particularly in sub-Saharan Africa, where agricultural practices largely involve heavy physical labor.

Commenting on the importance of the study, Professor George Havenith from Loughborough University said: “This research once again demonstrates the significant impact that climate change will have on life in various parts of the world and quantifies the effects on agricultural productivity.

“Understanding the full impact of climate change on worker productivity allows us to predict the economic impact of climate change and guide mitigation efforts that keep workers safe while limiting productivity losses.

“We hope the suggested adaptations can help guide investments to support farmworkers and food security as climate change makes the outdoor working environment increasingly inhospitable.”