For example, dust may impact hurricanes, as Evan suggests, but dust has not been a major tool in storm predictions. There are just too many unanswered questions. And at a time when humans seem to be getting blamed for everything, it's really unclear just how much humans are contributing to the production of dust. In one recent study, scientists at the National Center for Atmospheric Research in Boulder concluded that the human contribution to dust from activities like cultivation and urbanization ranges from 60 to 24 percent of the dust present in the atmospheric. That's a huge gap, but at least we're not to blame for the rest of it.
It may seem logical that global warming would cause more land to dry out, and thus more dust could be blown across the Atlantic, diminishing hurricanes. But these researchers concluded just the opposite. Increased carbon dioxide, one of the principal drivers of global warming, should fuel more vegetation, thus retaining more dust in the soil. So if there's less dust with global warming, the Atlantic should grow even hotter, and the hurricane season more dreadful.
But even Evan isn't sure of that.
"This is just one study, so I wouldn't ring the alarm bells just yet," he said of the possible impact of global warming.
While there is some debate over the role of dust in big storms, there is much less debate about the fact that many conditions around the entire Earth are influenced by something as mundane as dust.
Scientists at NASA's Goddard Space Flight Center say about eight million tons of dust from the Sahara Desert reached as far west as Puerto Rico in one year alone. Or as one scientist put it, that's equivalent to eight million one-ton pickup trucks.
And all that dust does more than just modify the weather. Minerals in the dust, like iron, aluminum, calcium, magnesium and potassium, settles into the ocean to the benefit of some species and detriment of others. Tiny plants, like phytoplankton, should prosper, but that could lead to enormous growth in larger species that feed on the little guys, thus throwing off the balance of nature. And increased iron could cause red tides of toxic algae, killing birds and other wildlife.
Some scientists are very concerned about the possible presence of harmful bacteria in dust, and Florida, which gets about 4 percent of the dust that blows off the Sahara, isn't the only place where people need to worry. In recent years scientists have documented that dust from the great storms of China reach the west coast of North America, possibly carrying pathogens.
So it isn't just dust. It's a powerful, global force.
Lee Dye is a former science writer for the Los Angeles Times. He now lives in Juneau, Alaska.