Extreme heatwaves pose a severe and growing threat to global dairy production, with scientists warning of significant declines in milk yields. An Israel-based study, drawing on 12 years of records from over 130,000 cows, found that extreme heat reduces a dairy cow’s milk-producing ability by 10%. Even a single hour of wet-bulb temperature above 26$^\circ$C can decrease a cow’s daily milk output by 0.5%, with lingering effects persisting for up to 10 days post-exposure. This stark reality signals a critical challenge for the international dairy community as climate change intensifies.

Projections for mid-century paint a concerning picture: by 2050, average daily milk production could see a global reduction of 4% due to worsening heat stress. Researchers from the Universities of Jerusalem, Tel Aviv, and Chicago emphasize that this decline will disproportionately impact the 150 million households worldwide that rely directly on milk production for their livelihoods. The most severe consequences of heat stress on dairy farms are expected in South Asia, a region projected to account for over half of the global growth in milk production in the coming decade, making it highly vulnerable to debilitating heatwaves.

While the dairy industry contributes to climate change—cattle are responsible for approximately a third of human-caused methane emissions—farmers are proactively implementing adaptation strategies to mitigate heat stress. In Israel, where the study was conducted, nearly all farms utilize various technologies, including providing access to shade and direct cooling methods such as ventilation and sprinklers. These efforts are crucial for animal welfare and maintaining productivity in increasingly challenging environmental conditions.