New research from the University of California Los Angeles announced on Apr. 28 finds that airborne desert dust in the atmosphere traps about twice as much heat as climate models have previously estimated. The study, led by UCLA atmospheric scientist Jasper Kok, shows that this effect is equal to roughly 10% of the warming caused by human-emitted carbon dioxide, compared to earlier estimates of only about 5%.
The findings could help improve both short-term weather forecasts and long-term climate projections by increasing the precision of current models. Atmospheric dust plays a complex role in Earth’s climate system because it can reflect sunlight back into space and also absorb and retain heat like an insulating blanket. While previous studies suggested dust has an overall cooling effect, this new research indicates its heat-trapping ability is stronger than thought.
“Improving how models represent warming caused by dust could therefore help improve both weather forecasts and climate projections,” said Kok, a professor in UCLA’s department of atmospheric and oceanic sciences. “Regions with more dust will be a little warmer, leading to higher surface temperatures and faster evaporation. This can alter atmospheric motions and shift where and when rainfall occurs — for example, by suppressing precipitation in some regions while enhancing it in others. Such effects are expected to be strongest in regions downwind of major deserts such as in the Sahara, the Middle East and East Asia.”
Kok explained that depending on factors like size, elevation, concentration, and other properties, atmospheric dust may cool or warm the planet through different mechanisms. His team’s new estimate found that “atmospheric dust traps about a quarter of a watt per square meter of heat by absorbing and scattering the heat radiation emitted by the Earth,” which he described as comparable to one-tenth of carbon dioxide’s warming effect from all human activities.
To reach their conclusions, researchers used satellite data on atmospheric dust abundance along with aircraft measurements for particle sizes; they also incorporated simulations from climate models showing spatial patterns for global distribution. Meteorological data provided information on temperature structures within Earth’s atmosphere.
The University of California Los Angeles has been associated with notable figures such as Nobel laureates and MacArthur Fellows according to the official website. The university also has a history of excellence across scholarship, arts and athletics according to its official website. Its academic environment fosters diverse perspectives through inclusive programs as reported by UCLA, supported on its 419-acre campus according to UCLA. The institution operates within the University of California system according to its official website.
Looking ahead, Kok said: “A lot of my work is about fine-tuning climate models… But that doesn’t mean the models are wildly wrong; they’re just not 100% perfect.” He added that understanding these complexities makes future predictions more reliable given ongoing changes observed worldwide.