Over the past decade, climate change has gone from being a distant concern to a reality that affects everyone in multiple ways. As extreme weather events become more frequent and intense, one aspect of particular concern stands out: the impact on workers' health. For instance, farmers working in the sun are experiencing higher rates of heatstroke and dehydration, while first responders facing increasingly powerful wildfires are at risk of respiratory issues due to the smoke. These are just a few examples of how the effects of climate change manifest themselves acutely in work environments. This text will review these and other health impacts in more detail.
The average land surface temperature in 2023 was the warmest on record. Between 2011 and 2020, the average land surface temperature was 1.1 °C warmer than the average temperature at the end of the 19th century. It has caused widespread and rapid changes in the atmosphere, land, oceans and polar regions. Global warming has resulted in climatic extremes on all continents, as evidenced by the increased frequency and severity of heat waves, intense precipitation, forest fires, droughts and tropical cyclones.
Natural disasters magnified by the climate crisis have profound effects on human health and, thus, on health systems. The impacts encompass direct and indirect consequences of these disasters, some of which may manifest themselves months or years later. Immediate impacts include deaths, physical injuries, malnutrition, as well as respiratory and cardiovascular diseases. In addition, exposure to infectious diseases such as cholera, dysentery and typhoid results from consuming contaminated food or water. On the other hand, stress, trauma and homelessness caused by natural events can contribute to the development of mental health disorders such as anxiety, depression and post-traumatic stress disorder.
Six climatic events have an influence on health, such as people's physical environment, as well as social and economic well-being. These events include floods, droughts, heat waves, tropical storms, forest fires, and sea level rises. At present, these phenomena have a particularly damaging effect on air and water purity, as well as on food availability. Long-term effects could include stunted child growth due to malnutrition, as well as respiratory or cardiovascular diseases triggered by poor air quality due to forest fires or prolonged heat waves.
Workers, especially those who work outdoors, are often the first to face the impacts of climate change, often for more extended periods and with greater intensity than the rest of the population. This vulnerability, which affects approximately 1.2 billion workers and results in more than 860,000 deaths annually, underscores the urgent need for updated occupational health and safety policies.
Sectors with a high employment rate are also among the most susceptible to the effects of climate change. Today, around 1.2 billion jobs depend directly on the effective management and sustainability of a healthy environment, especially in agriculture, fisheries and forestry sectors. As ecosystems are affected and essential resources become scarcer, many jobs in these and other sectors are at risk, underscoring the need for immediate action.
Maintaining a body temperature around 37°C is crucial for the proper functioning of the human body. If the temperature exceeds 38°C, physical and cognitive functions deteriorate. When it exceeds 40.6°C, the risk of organ damage, loss of consciousness and, in extreme cases, death increases considerably. A worker may face heat stress at work, which refers to the excess heat load. Several factors may act alone or in combination. These factors include environmental conditions, such as air temperature and humidity, and heat sources in industrial environments, such as heat emitters and machinery. The duration and intensity of physical exertion are also contributing factors, as are occupational health and safety requirements.
According to the International Labour Organisation, around 23 million occupational injuries and 18,970 deaths occur each year due to exposure to high temperatures at work. In addition, by 2020, an estimated 26.2 million people were suffering from chronic kidney disease attributable to this same exposure to heat during their working hours. Workers of all ages are susceptible to the harmful effects of excessive heat, even the youngest workers. However, older adults are particularly affected due to lower tolerance to high temperatures and poorer aerobic capacity.
The impact of extreme heat varies by sector, but those most at risk are outdoor employees in physically demanding jobs and those working indoors in poorly ventilated, temperature-unregulated locations. These jobs include agriculture, environmental goods and services (natural resource management), construction, manufacturing, rubbish collection, emergency repair work, transportation, tourism and sports, and a large part of the informal sector, such as street vending.
Different adverse health impacts are associated with heat stress in the workplace. Acute effects range from mild to severe and include heat stroke, exhaustion, cramps, rashes, rhabdomyolysis (breakdown of muscle tissues releasing a harmful protein into the blood) and even death. Long-term impacts of exposure to high temperatures include cardiovascular disease, acute kidney injury and chronic kidney disease, all of which are associated with hot work environments. Extreme heat can also increase the risk of workplace accidents and injuries due to problems such as sweaty hands, fogged safety glasses, dizziness and decreased brain function. It may also aggravate these risks by causing disorientation, impaired judgement, loss of concentration, reduced alertness and fatigue. Female workers may face increased risks due to their occupational roles, such as those in subsistence farming, and their vulnerability during different life stages. These risks are particularly pronounced during pregnancy, where complications can include hypertension, miscarriages, and stillbirths. The physical demands of their jobs, combined with the added stress and health challenges of pregnancy, make these women especially susceptible to these serious health issues.
The significant economic costs associated with workplace accidents and illnesses represent a loss of resources on both national and global levels. Employers will face potential reductions in labor productivity and workforce availability. Additionally, financial losses due to increased production costs, accidents and injuries, and absenteeism must be considered. Even if global warming is limited to 1.5°C above pre-industrial levels by the end of the century, cumulative financial losses from heat-related illnesses alone are expected to reach $2.4 trillion by 2030.
Climate change poses a significant threat to ecosystems and, consequently, to the 1.2 billion jobs that rely on them, including those in agriculture, forestry, and fishing. Entire regions may become unproductive, and many work environments could become too hot to safely work in. Additionally, natural disasters will damage essential workplace infrastructure and result in loss of life. This will likely lead to increased climate-induced migration, a rise in informal employment, and higher unemployment rates. For instance, if the global temperature rises by 2 degrees Celsius by the end of the century, the number of asylum applications to the European Union (EU) is expected to double.
As we can see from the table, the effects caused by climate events require specific determinants to affect the natural environment, health and the economy. In addition to the direct impacts on human health already mentioned (both physical and mental), climate events also have severe economic repercussions. For instance, crop damage and food insecurity lead to higher prices for primary commodities, contributing to inflation and widespread financial instability. This chain of impacts culminates in increased poverty and vulnerability of affected populations, exacerbating existing social and economic inequalities. These economic consequences further underscore the need for comprehensive policy changes to address the health impacts of climate change on workers.
A comprehensive global, multisectoral response is necessary to address the impacts of climate change through both mitigation and adaptation strategies. Multilateral climate agreements, are key mitigation strategies for combating climate change. These agreements should be complemented by national and workplace-level mitigation policies. Climate adaptation efforts are preventive measures aimed at protecting workers, economies, and communities from the impacts of climate change. Since it is unlikely that climate mitigation measures will yield immediate effects, it is crucial to have effective and targeted adaptation policies in place to ensure safe and healthy working environments.
With rising temperatures and extreme weather events, climate change significantly affects the health of workers forced to work in the high temperatures that are now the new normal. Every year, billions of workers face increased risks due to climate change, and these numbers will likely continue to rise unless measures are taken. The real urgency, however, is to lower greenhouse gas emissions to halt the rapid advance of climate deterioration. Adapting and mitigating these effects becomes crucial to preserving the health and lives of millions of workers worldwide, emphasizing the shared responsibility we all have in this global issue.
