Global Agriculture Loses Billions of Working Hours to Heat, Study Says

More than 675 bil­lion labor hours are lost every year because of exces­sive heat and humid­ity, accord­ing to a new study from the Institute of Physics, a non-profit.

The research con­firms pro­jec­tions of annual labor losses way higher than pre­vi­ously esti­mated, equal to 1.7 per­cent of global (GDP).

According to sci­en­tists, those losses mostly impact agri­cul­ture and con­struc­tion but affect many dif­fer­ent sec­tors.

Globally, the pro­duc­tiv­ity loss related to exces­sive heat tops 2.1 tril­lion in pur­chas­ing power – the value of cur­rency in terms of the num­ber of goods or ser­vices one unit of money can pur­chase. They added that 10 per­cent of the pro­duc­tion capac­ity is lost to unbear­able out­door work­ing con­di­tions.

According to researchers, about 30 per­cent of those losses could be recov­ered by shift­ing work hours and hav­ing them resched­uled dur­ing cooler hours of the day. Still, the effects of such adap­ta­tion mea­sures will reduce as global tem­per­a­tures con­tinue to rise.

In the last four decades, heat-related labor losses increased at least nine per­cent, a trend that demon­strates how even small changes, as low as a 0.5 ºC rise in aver­age global tem­per­a­tures, might impact labor pro­duc­tiv­ity.

Another study, pub­lished in Nature Communications, shows how lost pro­duc­tiv­ity is directly related to increased warm­ing and that fur­ther adap­ta­tion mea­sures are needed to cur­tail losses and ensure worker safety in essen­tial sec­tors of the econ­omy.

“The globe has warmed over the last sev­eral decades. Humid heat expo­sure has increased and labor has already been impacted,” Luke Parsons, a post-doc­toral asso­ciate and lec­turer at Duke University and co-author of both stud­ies, told Olive Oil Times.

“It is pos­si­ble to esti­mate labor losses due to humid heat expo­sure over about the last 40 years, and how these losses have changed in var­i­ous regions,” he added.

Heat and humid heat rep­re­sent poten­tially dan­ger­ous con­di­tions for out­door work­ers as high tem­per­a­tures cou­pled with high humid­ity ham­per the body’s abil­ity to cool through sweat­ing.

That means that farm­ers and many other work­ers must often slow down their work and hydrate, or even stop work­ing and move to cooler loca­tions to allow the body tem­per­a­ture to grad­u­ally come down.

More than 70 per­cent of the global work­ing-age pop­u­la­tion – about four bil­lion peo­ple, accord­ing to researchers’ esti­mates – cur­rently live in envi­ron­ments where heavy labor losses due to humid heat exceed 100 hours per per­son per year.

“Our labor loss esti­mates are lim­ited to work­ers in agri­cul­ture, fish­eries, forestry and con­struc­tion, but these sec­tors rep­re­sent a sig­nif­i­cant pro­por­tion of the over­all work­force in many regions, with approx­i­mately 69 per­cent of work­ers in low-income coun­tries work­ing in agri­cul­tural and other pri­mary-sec­tor occu­pa­tions,” the researchers wrote.

“Workers in many loca­tions are already stop­ping labor in the hottest part of the day because it is too uncom­fort­able to work or local reg­u­la­tions require work to halt if it becomes too hot,” Parsons added.

“Rescheduling labor to the cooler parts of the day is one poten­tial adap­ta­tion strat­egy,” he said. ​“However, we show that as the globe warms, the coolest hours of the day also get warmer, so this adap­ta­tion strat­egy becomes less effec­tive with each degree of global warm­ing.”

“The focus of our research was not on other adap­ta­tion meth­ods, but [those] can include ade­quate worker hydra­tion, rest breaks in the shade, dif­fer­ent types of cloth­ing that pro­tect work­ers from the sun or allow them to cool them­selves more effi­ciently, mech­a­niza­tion of labor, move­ment of the most inten­sive tasks to cooler hours of the day, mov­ing work that exposes work­ers to direct sun to the shade and acclima­ti­za­tion to heat,” he con­tin­ued.

According to the researchers, labor pro­duc­tiv­ity losses due to work rate reduc­tions might amount to €250 bil­lion to €275 bil­lion per year glob­ally.

Most of these losses occur in low to mid­dle-income coun­tries, at lat­i­tudes where agri­cul­ture and con­struc­tion work­ers often find them­selves work­ing in unsafe con­di­tions.

“In the com­ing cen­tury, human-dri­ven warm­ing of the planet will push many low-lat­i­tude regions even fur­ther into uncom­fort­able and unsafe con­di­tions for out­door labor, with heat expo­sure increas­ing rel­a­tively lin­early as a func­tion of global tem­per­a­tures,” the researchers wrote.

The research shows how the largest per-capita labor losses occur in Qatar, with 354 hours lost per per­son com­pared with the global aver­age of 81 hours lost per per­son from 2001 to 2020.

The study pro­jected that losses in Qatar will con­tinue increas­ing more quickly than the global aver­age for each degree Celsius of tem­per­a­ture rise. With an increase of just 1 ºC, the global aver­age would grow to 134 hours per per­son with Qatar’s losses spik­ing to 530 hours per per­son.

“Humid heat expo­sure and asso­ci­ated poten­tial heavy labor losses have increased across south­ern North America, much of Central and equa­to­r­ial South America, equa­to­r­ial Africa, Southwest Asia, South Asia, Southeast Asia, and parts of Oceania,” Parsons said.

The research shows how the global aver­age loss would reach 212 hours per per­son with a 2 °C rise and 457 hours with a 4 °C rise.

To bet­ter under­stand new chal­lenges asso­ci­ated with the impacts of heat on labor loss, the sci­en­tists said more research needs to be done.

“Although humid heat expo­sure and its impacts on worker pro­duc­tiv­ity are impor­tant, our knowl­edge of how work­ers in spe­cific loca­tions and sit­u­a­tions respond to heat expo­sure is lim­ited,” Parsons said.

The Duke University researcher also stressed how cur­rent data used by many researchers ​“rely on past stud­ies of agri­cul­tural work­ers and min­ers that mea­sured how much work pro­duc­tiv­ity was lost when work­ers were exposed to var­i­ous lev­els of heat and humid­ity.”

“The scale and dis­tri­b­u­tion of the impacts of humid heat on labor loss indi­cate sig­nif­i­cant risks to the resilience and well-being of out­door work­ers, as well as the fam­i­lies that rely on these work­ers for their liveli­hood,” the sci­en­tists con­cluded. ​“The abil­ity of work­ers to earn incomes in safe work envi­ron­ments is impor­tant for tack­ling global poverty, address­ing house­hold cli­mate resilience and for national eco­nomic devel­op­ment.”

• Nature
• Institute of Physics