At a Glance
- As climate change accelerates, scientists have found that the atmosphere is becoming “thirstier,” meaning it demands more water to evaporate, which impacts agriculture and water usage.
- A new study introduces the concept of “thirstwaves,” which are extended periods of extremely high evaporative demand that can harm crops and reduce agricultural productivity by focusing on land drying rather than temperature extremes.
- Thirstwaves occur when evapotranspiration exceeds the 90th percentile for at least three days, and these events have become more frequent, intense, and long-lasting in the contiguous United States from 1981 to 2021.
- The study revealed that thirstwaves have significantly increased in intensity, duration, and frequency, particularly in regions like the High Plains, Southwest, and West Coast. In contrast, the likelihood of no thirstwaves has decreased.
- Understanding and tracking thirst waves is crucial for improving agricultural practices and water management strategies. Farmers and regulators must adapt to increased atmospheric water demand to ensure food and water security.
As climate change continues to heat the planet, scientists have found that the atmosphere is becoming “thirstier,” meaning it demands more water to evaporate. This increased evaporative demand, which is the amount of water that could potentially evaporate from the surface, has major impacts on agriculture and water use. One key measure for tracking this demand is evapotranspiration, which estimates how much water would evaporate from crops like well-watered grass. While previous studies have shown that evaporative demand has been increasing, they have not fully explored the extreme demand spikes over long periods.
A new study led by Meetpal Kukal and Mike Hobbins has introduced the concept of “thirstwaves,” which are extended periods of extremely high evaporative demand. These events are similar to heatwaves, except that they focus on the drying out the land instead of extreme temperatures. Thirstwaves occur when the evaporative demand, measured by evapotranspiration, exceeds the 90th percentile for at least three days. This phenomenon can harm crops and reduce yields, making it a significant concern for agricultural productivity.
The study, published in Earth’s Future, analyzed data from the contiguous United States between 1981 and 2021, tracking thirstwave events during growing seasons from April to October. The researchers found that thirstwaves have become more frequent, intense, and long-lasting. Over the past four decades, these events’ intensity, duration, and frequency have increased significantly in many areas, particularly in regions like the High Plains, Southwest, and West Coast. The study also showed that the likelihood of a region experiencing no thirstwaves during the growing season has drastically decreased.
Understanding and tracking these thirstwaves is critical for managing water resources and crop production, especially as the climate warms. This research highlights the need for improved agricultural practices and water management strategies to cope with the increasing demand from the atmosphere. As temperatures rise and thirstwaves become more common, farmers and water regulators must adapt to these changing conditions to ensure stable food and water supplies for the future.
References
- Owen, R. & American Geophysical Union. (2025, April 7). ‘Thirstwaves’ are growing more common across the United States. Phys.Org; American Geophysical Union. https://phys.org/news/2025-04-thirstwaves-common-states.html
- Kukal, M. S., & Hobbins, M. (2025). Thirstwaves: Prolonged periods of agricultural exposure to extreme atmospheric evaporative demand for water. Earth’s Future, 13(3), e2024EF004870. https://doi.org/10.1029/2024EF004870
