Jun 4, 2025 06:07 PM
https://www.eurekalert.org/news-releases/1086237
INTRO: Hot air holds more moisture. That’s why you can blow your hair dry even after a steamy shower. It’s also what dumps rain in the tropics and sucks water from desert soils.
A new study, published in Nature, shows that the atmosphere’s growing thirst for water is making droughts more severe, even in places where rainfall has stayed the same. The paper details how this “thirst” has made droughts 40% more severe across the globe over the course of the past 40 years.
“Drought is based on the difference between water supply (from precipitation) and atmospheric water demand. Including the latter reveals substantial increases in drought as the atmosphere warms,” said co-author Chris Funk, director of the Climate Hazards Center at UC Santa Barbara.
Droughts are usually blamed on a dearth of rain. But scientists have discovered another factor at work: warming air is increasing the atmosphere’s evaporative demand. Atmospheric evaporative demand (AED) acts like a sponge, soaking up moisture faster than it can be replaced. This can pull more water out of soils, rivers and plants.
It’s not clear whether a warmer atmosphere will make droughts more or less intense, frequent and widespread. “As the atmosphere warms, air at a constant relative humidity will hold more water vapor, so rainfall may increase,” Funk explained. “But at the same time, atmospheric evaporative demand is also expected to increase. So which is increasing more quickly?”
Funk joined an international team of scientists to examine the role AED is playing in exacerbating droughts around the world... (MORE - details, no ads)
INTRO: Hot air holds more moisture. That’s why you can blow your hair dry even after a steamy shower. It’s also what dumps rain in the tropics and sucks water from desert soils.
A new study, published in Nature, shows that the atmosphere’s growing thirst for water is making droughts more severe, even in places where rainfall has stayed the same. The paper details how this “thirst” has made droughts 40% more severe across the globe over the course of the past 40 years.
“Drought is based on the difference between water supply (from precipitation) and atmospheric water demand. Including the latter reveals substantial increases in drought as the atmosphere warms,” said co-author Chris Funk, director of the Climate Hazards Center at UC Santa Barbara.
Droughts are usually blamed on a dearth of rain. But scientists have discovered another factor at work: warming air is increasing the atmosphere’s evaporative demand. Atmospheric evaporative demand (AED) acts like a sponge, soaking up moisture faster than it can be replaced. This can pull more water out of soils, rivers and plants.
It’s not clear whether a warmer atmosphere will make droughts more or less intense, frequent and widespread. “As the atmosphere warms, air at a constant relative humidity will hold more water vapor, so rainfall may increase,” Funk explained. “But at the same time, atmospheric evaporative demand is also expected to increase. So which is increasing more quickly?”
Funk joined an international team of scientists to examine the role AED is playing in exacerbating droughts around the world... (MORE - details, no ads)