Firefighters, farmers, construction workers, factory workers to feel greatest impact
Heat-stress related labour capacity losses will double globally by 2050 with a warming climate, according to a recent study by the National Oceanic and Atmospheric Administration (NOAA).
The impact will be felt the most by those who work outside or in hot environments, the study says, listing professions such as firefighters, bakery workers, farmers, construction workers and factory workers as the most vulnerable. Mid-latitude and tropical regions, which include South and East Asia, North America, and Australia also have increased vulnerability, according to the study.
The research uses existing occupational health and safety thresholds to establish a new metric to quantify a healthy, acclimated individual’s capacity to safely perform sustained labour under environmental heat stress. Heat stress can result in heat stroke, heat exhaustion, heat cramps, and can also increase the risk of injuries. Age, obesity, and medical conditions such as heart disease or high blood pressure can also put workers at greater risk of heat stress.
“Most studies of the direct impact of global warming on humans have focused on mortality under either extreme weather events or theoretical physiological limits,” said John Dunne, research oceanographer at NOAA Geophysical Fluid Dynamics Laboratory and lead author of the study. “We wanted instead to describe climate warming in practical terms that people commonly experience already.”
Peak summer months of heat stress currently reduce labour capacity to about 90 per cent of full potential. By 2050, labour capacity is predicted to drop to 80 per cent in peak months, even with reductions of greenhouse gas emissions, according to the study.
The findings indicate that, even with reductions of greenhouse gas emissions, heat stress would still force a doubling of labour capacity losses by the middle of this century, with more severe reductions under continued highest emissions scenarios out to 2200. If greenhouse gas emissions continue to rise under the higher projections, increased heat stress would reduce labour capacity to 39 per cent in peak months by 2200, the study says.
Humans have a range of temperature and humidity over which they can environmentally adapt and work safely and productively, according to NOAA. The thresholds come from guidelines established by the National Institute for Occupational Safety and Health and adopted operationally by many institutions and military organizations around the world.
The NOAA is a federal agency within the U.S. Department of Commerce. The Washington, D.C.-based administration monitors the condition of the oceans and the atmosphere to predict changes in climate, weather, oceans, and coasts.