Climate Trivia: Earth’s Largest Dust Source
At any given time, there is about 22 million tons of dust suspended in the atmosphere around us. Dust has important effects on Earth’s climate. It absorbs and scatters incoming radiation, affecting how much sunlight reaches the Earth’s surface and how much is reflected back into space. How much sunlight reaches the Earth’s surface helps drive surface temperatures and rainfall patterns. Dust also serves as a fertilizer – dust from barren regions can travel thousands of miles and fertilize plants that grow in lush regions. The Amazon rainforest is one such lush region that is stimulated by fertilizing dust from afar.
Trivia Question: What region is Earth’s largest single source of atmospheric dust?
a. The Great Basin
b. The Gobi Desert
c. The Sahara Desert
d. The Atacama Desert
The correct answer is c. More dust comes out of Africa’s Sahara Desert than any other region on Earth. The Bodélé Depression in Chad (central Africa) may be Earth’s largest single dust “hot spot.” About half of the dust emitted from the Sahara comes from this 8650 square mile barren lake bed. Each year, about 100 dust plumes rise from the depression. Each plume contains about 700,000 tons of dust.
(Source: Grini, A et al. “Model simulations of dust sources and transport in the global atmosphere: Effects of soil erodibility and wind speed variability.”Journal of Geophysical Research – Atmospheres. 110 (2005): D02205 and Washington, R. et al. “Dust as a tipping element: The Bodélé Depression, Chad.” Proceedings of the National Academy of Sciences 49 (2009): 20564-20571)