The amount of dust generated by desert windstorms has grown markedly since the mid-19th century, helping to offset the global rise in temperature, new research shows.
Airborne dust, which reflects a small measure of the sun’s light, has reduced warming by as much as 8 percent, the study found. The implications of the research are clear, authors say: If dust levels fail to keep growing, warming will ramp up even further.
For the study, researchers gauged the current level of dust in the air using satellite data and ground measurements, and they reconstructed past levels by evaluating dust in ice cores, ocean sediment, and peat bogs. The study revealed a consistent rise in dust levels, possibly due to drier weather, more powerful winds, or the building of irrigation channels that direct water away from lakes and wetlands. Since around 1850, the volume of dust in the atmosphere has grown by 55 percent, according to the study, which was published in the journal Nature Reviews Earth and Environment.
Over the same period, temperatures have risen 2.2 degrees F. Without the influence of dust, they would have risen another 0.1 degrees F, UCLA climate scientist Jasper Kok, the study’s lead author, said in a statement. This effect is currently unaccounted for in climate models, he said.
“By adding the increase in desert dust, which accounts for over half of the atmosphere’s mass of particulate matter, we can increase the accuracy of climate model predictions,” Kok said. “This is of tremendous importance because better predictions can inform better decisions of how to mitigate or adapt to climate change.”