The valley of Bodélé has unique geographical characteristics that make it the world’s largest dust supplier. Two mountain chains running nearly parallel to each other shape this natural “wind tunnel,” which becomes increasingly narrow as it approaches the Atlantic coast. As the wind penetrates the valley it picks up speed and more dust—it has been known to stir up dust clouds observable by satellite.
This narrow valley supplies 56 percent of the total dust arriving annually to the Amazon, at the same time contributing various mineral nutrients and fertilizing the soil. In the end, this means that 50 million tons of particles finer than sand make the more than 6,000-mile journey across the sea each year, feeding life on the other side of the world.
The dust not only enriches the forest soils but, incidentally, also is associated with the cycle of proliferation of plankton in the Atlantic Ocean through its contribution of nutrients required for the plankton’s breeding.
The ‘Bad Side’ of Dust
The valley of Chad doesn’t just stop at spreading its dust to the Brazilian jungle. Gusts often make it as far as the Gulf of Mexico, Cuba, and the Canary Islands—among other places. Furthermore, the Earth’s atmosphere gets loaded with this dust, adding more to what is already produced in other parts of the world.
According to some scientists, the world’s dust supply—which increases in volume between 2,000 and 3,000 million tons annually—intensifies respiratory problems, contributes to climate change, and is the primary cause for a phenomenon known as “red tide,” where plankton density becomes so great that it colors the sea red.
Dust is a born traveler. It can set off from the Sahara and make it to the United States, or it can start from China and go all the way to Europe. Everything depends on which direction the wind blows. When it is deposited in fresh soil, it can bring with it sicknesses; and when it ends up in the sea, it can alter the reproductive cycle of animals. The north and south poles also receive their share of punishment from the atmospheric dust, as it diminishes the refraction of light. This in turn increases one of the factors responsible for the greenhouse effect.
Storms of dust and sand can also swallow up entire cities and villages, sealing off the sky with a profound darkness that can last for hours. The quality of these ominous storms, coupled with the many lives they can claim, has prompted some people to see these storms as “divine warnings.”
Other Dust Origins
This massive daily production of nearly 700,000 tons of African dust has increased as much as10 times in the last 50 years. But as stated above, the world’s dust supply does not only come from Africa. Developments such as deforestation and an increase in draughts also add to the world’s growing dust. Other factors can also contribute a few extra tons—pollution from vehicles, the emissions of toxic smoke from factories, as well as other sources related to human technology.
