Heat Stress Threatens Global Cheese Production

Heat Stress Threatens Global Cheese Production

We all know climate change is wreaking havoc on the planet, but now it’s threatening something much closer to home: our favorite cheeses. From creamy Italian Parmigiano-Reggiano to rich Israeli labneh, heat waves are hitting dairy farms hard, and cheesemakers are starting to feel the pinch.

When the Cow Feels the Heat, Cheese Feels It Too

Recent reports reveal that rising summer temperatures are taking a serious toll on milk production worldwide. In Italy, government data analyzed by the Modena-based dairy research center CLAL showed that between 2022 and 2024, milk output from Italian cows dropped by an average of 17% during the summer months (March through September). That’s nearly a fifth of milk lost—just when demand for cheese peaks.

But it’s not just Italy. Studies in Israel show that even a single day of extreme heat can slash milk output by up to 10%, with lingering effects lasting over a week. As Eyal Frank, assistant professor at the Harris School of Public Policy and coauthor of the Israeli study, noted, her team tracked more than 130,000 cows over a decade and surveyed 300+ farmers. They found that “even the most high-tech, well-resourced farms are deploying adaptation strategies that may be an insufficient match to climate change.”

The problem isn’t only the quantity of milk—it’s the quality. Heat-stressed cows produce milk that curdles more slowly and sets less predictably, creating a headache for cheesemakers whose recipes depend on precise consistency. As Agro Review points out, this makes the already delicate art of cheese production even trickier.

Humidity: The Silent Milk Killer

It turns out, it’s not just high temperatures but high humidity that does the real damage. Researchers measuring “wet-bulb” temperatures—a metric combining heat and humidity—found that production drops sharply when cows experience 78.8°F or higher. Those humid, “steam bath” conditions can disrupt milk yields for more than a week after just a single day in the sun.

Farmers aren’t sitting idle. Many Israeli dairies rely on misters, fans, and other cooling technologies. But the results are limited. The same study showed these methods offset only about half the losses on moderately hot days and 40% on the hottest ones. “The hotter it gets, the less they help,” the researchers concluded.

Ayal Kimhi, associate professor at the Hebrew University of Jerusalem and coauthor of the study, added: “Dairy farmers are well aware of the negative impacts that heat stress has on their herds, and they use multiple forms of adaptation. Adaptation is costly, and farmers need to carefully balance the benefits they obtain versus the costs.” In other words, fully insulating cows from heat is economically unrealistic for most farms.

A Global Challenge

This isn’t just an Italian or Israeli problem. Without effective cooling methods, the top 10 milk-producing countries could see global dairy output drop by 4%, with major players like India, Pakistan, and Brazil facing even steeper losses.

The U.S. is already seeing the effects. Researchers at the University of Illinois published a study that found that heat stress has already shaved about 1% off total annual milk yield in the Midwest and East—equivalent to 1.4 billion pounds of milk and $245 million in lost revenue over five years. By 2050, these losses could rise 30% under certain climate scenarios.

As Marin Skidmore, assistant professor at Illinois, explained: “Cows are mammals like us, and they experience heat stress just like we do… For dairy producers, the heat impact is a direct hit on their revenue.” Solutions likely require a mix of financial incentives for farmers and research into better heat mitigation strategies.

Cheese lovers may not notice the difference in their favorite Brie or Pecorino just yet, but the writing is on the wall: heat waves are changing the game for dairies around the world. From milk yields to curd texture, climate-driven disruptions are rippling all the way from farm to table.

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References:

Food & Wine Farmers Are Struggling to Keep Cows Cool — and Cheese on Shelves

Agro Review Extreme Heat Threatens Italy’s Beloved Cheese Varieties

New York Times The Climate Is Changing, Cows Are Stressed and Italy’s Cheesemakers Are Worried – The New York Times

Science Advances High-frequency data reveal limits of adaptation to heat in animal agriculture | Science Advances