Extreme Heat Could Threaten $3.3 Billion Annually in California Outdoor Worker Earnings by Midcentury

Nation Lacks Mandatory Standards to Keep Workers Safe as US Extreme Heat Days Set to Quadruple

Published Aug 15, 2021

WASHINGTON—Between now and 2065, climate change is projected to quadruple U.S. outdoor workers’ exposure to hazardous heat conditions, jeopardizing their health and placing up to $55.4 billion of their earnings at risk annually if no action is taken to reduce global warming emissions, according to a new report released today by the Union of Concerned Scientists (UCS). This research is currently being reviewed for journal publication and is available on a preprint server. The last seven years have been the hottest on record. Without additional protections, the risks to workers will only grow in the decades ahead as climate change worsens, leaving the roughly 32 million outdoor workers in the United States to face a brutal choice: their health or their jobs.

The national press release, featuring nationwide findings and quotes from report authors, can be found here.

California currently has about 3.8 million outdoor workers, who comprise approximately 21 percent of the state’s total workforce. Below are the sobering results for California by midcentury, assuming no reduction in global warming emissions:

  • Outdoor workers are projected to face nearly $3.3 billion in total annual earnings at risk due to extreme heat. Riverside, San Bernardino and San Diego Counties would be hit hardest.
  • Outdoor workers in construction and extraction occupations are projected to face the highest total earnings at risk due to extreme heat at nearly $768 million annually, followed by those in protective service occupations at nearly $579 million annually.
  • The average outdoor worker risks losing about $740 in annual earnings due to extreme heat. Those in Imperial, Riverside and San Bernardino Counties are projected to be hit hardest.
  • The average outdoor worker in protective service occupations stands to lose the most annual income at roughly $1,300 due to extreme heat, followed by those in installation, maintenance and repair occupations at roughly $900 annually.
  • Outdoor workers risk losing six workdays on average annually due to extreme heat, up from one day historically. Those in Imperial, Riverside and San Bernardino Counties would be hit hardest.

The “Too Hot to Work” report combines county-level projections of dangerously hot days in the contiguous United States from the 2019 peer-reviewed UCS analysis “Killer Heat in the United States” with U.S. Census data on workers in the seven occupational categories with the highest proportion of outdoor jobs and U.S. Centers for Disease Control and Prevention (CDC) recommendations for keeping outdoor workers safe during extreme heat conditions. The number of workdays at risk is calculated by adding the partial days lost when the combined heat and humidity reach between 100 and 108 degrees Fahrenheit—a range in which the CDC recommends employers reduce work schedules—and entire days lost when such conditions exceed 108 degrees Fahrenheit, the threshold at which the CDC recommends employers stop work. The report does not project future changes in the number or distribution of outdoor workers. Midcentury results are determined by averaging the findings for the period between 2036 and 2065.

People of color have been and will continue to be hit especially hard by extreme heat for a number of reasons, including that they are disproportionately represented in many outdoor occupations. More than 40 percent of U.S. outdoor workers identify as African American, Black, Hispanic or Latino, despite these groups comprising about 32 percent of the general population. Outdoor workers who identify as African American, Black, Hispanic or Latino risk losing an estimated $23.5 billion in annual earnings by midcentury if no action is taken to reduce global heat-trapping emissions. Migrant and undocumented workers may be further constrained in their ability to seek safety protections from dangerous heat due to the threat of employer retaliation, which could even result in deportation.

About 20 percent of the U.S. labor force works outdoors, with significant numbers of outdoor workers located in urban areas and outdoor workers comprising a larger share of the local economy in rural communities. These workers are largely unprotected as federal guidelines are only recommendations. In addition to the CDC guidelines, the U.S. Occupational Safety and Health Administration (OSHA) merely suggests that employers implement safety precautions when the heat index, or “feels like” temperature, exceeds 90 degrees Fahrenheit. Only two states—California and Washington—have permanent heat standards to protect outdoor workers.

UCS experts found that workers could stay safe and continue to work most days if their schedules were adjusted to coincide with cooler hours and their workloads were reduced to light levels. Coupling these strategies would ensure most workers would lose fewer than seven days of work per year on average by midcentury. Report authors caution, though, that there are practical limits to how much workloads and schedules can be adapted, so reducing global warming emissions remains essential for limiting the number of extreme heat days workers will experience.

The analysis advises the United States to limit future extreme heat by urgently contributing to global efforts to effectively constrain heat-trapping emissions, investing in just and equitable solutions that get us to net-zero emissions no later than 2050. It also recommends that all levels of government take action now to better protect the nation’s essential outdoor workers.

The report urges Congress to adopt the “Asunción Valdivia Heat Illness and Fatality Prevention Act of 2021,” legislation named in remembrance of a California farmworker who died from preventable heat stroke after picking grapes for 10 hours straight in triple-digit temperatures. The bill would direct OSHA to set protective standards—such as mandating that employers provide adequate hydration, shade and rest breaks—for outdoor workers regularly exposed to heat.

Other worker safety recommendations include requiring employers to create science-informed heat safety plans that would be enforced by OSHA; implementing heat safety monitoring and reporting requirements; providing multilingual training to supervisors and workers so they can better recognize and respond to the dangers of extreme heat; and ensuring workers have access to fair wages, affordable health care, cool housing, and legal protections.

To view the report PDF, click here.

Spreadsheets with data are available by state and by county. National data results can be found here.

To use the interactive mapping tool, click here. The map, which becomes more detailed when you zoom in, allows you to learn more about outdoor workers’ exposure to extreme heat and the corresponding economic implications by county.

For all other materials, including state-specific press releases, corresponding blogs, a related “Got Science” podcast episode, and Spanish-language materials, click here.