Droughts are worsening worldwide, but it’s not just rainfall that’s changing. The atmosphere itself is becoming thirstier. A new study shows that rising atmospheric evaporative demand (AED) caused 40% of drought severity increases since 1981.
AED measures how much water the air “wants” from the surface. Hotter, drier, sunnier, and windier air pulls more moisture from soils and plants, even when rainfall stays steady.
Imagine rainfall as income and AED as spending. If spending grows but income stays the same, the water balance runs a deficit. This worsens droughts in many regions.
RISING AED DRIVES DROUGHT SEVERITY AND SPREAD
In a new study published in Nature, the researchers reveal AED not only deepens droughts but also expands their reach. Between 2018 and 2022, global drought-affected land grew 74%, with 58% of that due to increased AED.
The year 2022 was the worst drought year in four decades. Over 30% of land faced moderate to extreme drought, driven by sharp AED rises.
REAL-WORLD IMPACTS: EUROPE, AFRICA, AND BEYOND
In Europe, widespread drying cut river flows, hurt hydropower, stressed crops, and caused water shortages in cities. This strained water, food, and energy sectors, threatening livelihoods. East Africa experienced similarly severe drought largely linked to rising AED.
UNDERSTANDING AND PREPARING FOR A THIRSTIER FUTURE
The research combined temperature, humidity, wind, and solar data to track AED globally. It highlights regions like western and eastern Africa, southwestern US, and parts of Australia as especially vulnerable.
Ignoring AED risks underestimating drought danger. As global temperatures climb, droughts will grow more frequent and severe. Preparing for this atmospheric thirst is urgent.
TAILORING DROUGHT SOLUTIONS TO THE DRIVERS
Knowing whether drought stems from rainfall drops or rising AED shapes responses. When rainfall declines, focus should be on water storage and conservation.
When AED dominates, strategies must address evaporative loss and plant stress. Solutions include drought-resistant crops, efficient irrigation, soil health improvements, and habitat restoration.
Ignoring the atmospheric demand misses a key piece of the drought puzzle. Our changing climate demands smarter, more comprehensive drought planning.
