[Op-Ed] Climate change is burning the hands that feed us

As California’s Central Valley continues to heat up, agriculture workers, like Lourdes Cardenas, face long working hours, hotter conditions, and increased risk of poor health. Farmworkers and researchers alike are calling for stronger protections and improved working conditions.

^{California farmworkers safely harvest seasonal crops using personal protective equipment.}

^{Photo by: Lance Cheung, Public Domain, U.S. Department of Agriculture}

3:00am. Lourdes Cardenas snoozes her blaring alarm. As she cracks open her eyes, the dark summer sky greets her, and she knows it’s time to get ready for another day out in the Fresno fields. Soon, she’ll be picking grapes and bell peppers, harvesting this season’s crops. Cardenas isn’t the only one. Farmworkers across California’s Central Valley have to wake up this early to beat the heat, and “if they don’t leave by 4am, they’re already late” says Linda Duran, Organizing Coordinator at the Fresno United Farm Workers Foundation office. June means that their season is in full swing, and they hope to work as much as they can before the sun begins scorching the rows of harvest – an unbearable heat that Cardenas says is only getting worse.

Climate change has shaken California’s agriculture industry in recent decades. With Fresno having its first heat advisory on May 30, 2025, these temperatures climbing above 100°F hint at yet another scorching summer.1,2 Already, farmworkers face long hours in the fields and they aren’t just uncomfortable due to the heat. Duran says they are facing health issues like lung problems and asthma as a direct result of the increased temperatures and air pollution. And as a secondary effect of climate change, Cardenas has noted that pesticide use has increased to keep up with unpredictable crop seasons. This, in turn, has caused rashes, says Duran. All mixed with a lack of personal protective equipment and breaks in the shade, farmworkers’ livelihoods and productivity are at even greater risk than ever before.

Luke Parsons, a climate scientist at The Nature Conservancy, studies how heat stress for workers has changed over time. Parsons says that using weather model data and agriculture worker population statistics, they’ve found “almost everywhere in the globe where it’s already hot, more days and hours every year are crossing thresholds where it becomes unsafe for people to work outside at a high intensity, like agriculture work, for extended periods.”

Fresno’s geography creates a perfect storm for both extreme heat and poor air quality. Sam Heft-Neal, a research fellow at Stanford’s Center on Food Security and the Environment,  explains that “much of the wildfire smoke from Northern California gets filtered down…and it’s also one of the hottest parts of the state.”

As the number of hot days and air pollution increases, the combination of these factors directly harms agriculture workers. Parsons explains that the human body operates best at certain temperatures, and working past them can cause “heart problems and long-term kidney problems,” alongside the risk of heat overexposure or even heat stroke. The physical tasks farmworkers have to complete are already straining, no matter the temperature. Parson notes that, “even if it’s very cool outside, you would start sweating.” Add in extreme heat, and workers are surely facing dangerous levels of heat exposure, he added.

The addition of air pollution further exacerbates these health issues. Although the combined effects of heat and air pollution are still being researched, Heft-Neal highlights research showing that “productivity goes way down during extreme pollution events…people just can’t function very well.”

Not only do these climate impacts have direct effects on the human body, but they affect the crops themselves, indirectly affecting farmworkers once again. Dr. Rodolfo Dirzo, Stanford biology professor and ecologist, explains that “Climate change has had the greatest effect on the uncertainty of the overall climatic conditions. It is now difficult to predict when it is the appropriate moment to harvest and the overall scheduling of agricultural practices.” Thus, climate change is creating an unpredictable harvest season, further disrupting farmworker schedules and working hours in the heat. This is particularly damaging for the Central Valley as it produces one fourth of the entire nation’s food supply, and an unstable season can be detrimental for production.3

Because of this uncertainty, Dirzo predicts that there will be an even greater increase in pesticide use to maintain yields. He describes how increased carbon in the atmosphere and decreased nitrogen in plants will cause “insects to eat more of the crops to compensate for the lack of nitrogen.” He believes this will “be a major issue because, what do farmers usually do? They try to control the pests.”

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Cardenas agrees. She sees that the land owners have been increasing their pesticide use because “the harvest is very slow. The harvests are smaller and lack flavor. The landowners want to continue production and make more money.” These pesticides are extremely harmful to the body as they contain toxic chemicals that can harm the respiratory system, cause skin irritation, and have even been linked to cancers like leukemia.4 

To protect workers from heat, air pollution, and pesticide exposures, their supervisors are legally required to provide personal protective equipment. They are also required to provide “two restrooms, two shade areas, and two big gallons of potable, fresh water with ice if there’s more than twelve people in the field,” says Duran. Heft-Neal highlights that these regulations have “seemed to have had a meaningful impact on injuries during extreme heat events…the relationship between temperature and worker injuries has gone down” as a result of these accommodations. 

However, these arrangements aren’t always provided. Duran says that protective gear often runs out and workers are being openly exposed to pesticides that have been sprayed just hours prior.  Cardenas says that she and her fellow frameworks are treated like “disposable rags,” as it is required that workers wait 24 hours after pesticides are sprayed prior to harvesting. She added that “if they cared about us, they would protect us and let us know not to continue to work” while pesticides are being sprayed or during extreme heat events.

Expanding beyond the fields, “labor protections and heat safety standards are essential to encourage both workers and employers to protect people when it’s too hot,” says Parsons. Heft-Neal also emphasizes that there need to be laws that not only “institute requirements to protect workers, but also enforce them. Just having them on the books is not sufficient.”

These are only the first steps, but they could protect farmworkers from the worst effects of climate change. “These outdoor workers are on the frontlines of climate change and their health and livelihoods are just at risk every day…this is a human issue,” says Parsons. Unlike a huge weather event like a hurricane or tornado that draws news coverage, Parsons calls farmworkers suffering from extreme heat “an invisible struggle.”

Cardenas urges American consumers to pay attention to the daily burdens that she and her fellow farmworkers face – ones that are only exacerbated by climate change. “We pick the food that goes to the tables of each and every one of you…Without our voices or yours, we aren’t heard. We’re invisible, and we don’t want to be invisible any longer.”

^{All notes from Lourdes Cardenas are in Spanish and have been translated by the author.}