Dust influences climate by altering the radiation budget of the atmosphere, and influences marine biogeochemistry by providing a source of essential micronutrients such as iron.
In something as tiny as a speck of dust lies the potential to change earth’s climate. When winds blow iron-rich dust off the continents, they give the plant-like algae floating on the surface of the oceans added nutrients to grow faster. Large algal blooms can draw down carbon from the atmosphere, and in extreme cases, cool earth’s climate. Researchers are trying to understand to what extent dust, by providing extra food for algae, or phytoplankton, may have helped to tip the planet into a deep freeze starting about 30,000 years ago. From the onset of the last ice age to its peak, about 18,000 years ago, carbon dioxide levels fell by about 100 parts per million. As much as 25 percent of that drop can be attributed to the effect of dust.