About 12 percent of all the Earth’s surface is covered in a biological crust, where microorganisms, lichens and ordinary algae bind sand particles into a solid layer. Spanish scientists have now estimated the effect of this crust on the amount of dust in the atmosphere. This turns out to be a big deal, but extensive land use and climate change could affect the layer and thus create more dust, they wrote in the science journal on Monday. natural earth sciences†
Lichen on pink granite on the coast of Brittany, France. (Photo by afp/ Damien Meyer)
Almeria
Scientists combined climate models with experiments to investigate the effects of the biological crust on dust formation. Living organisms bind sand and other small parts in it, so that the wind, for example, can blow less dust. Calculations show that with this layer the amount of dust in the atmosphere is 55 percent less than without the biological crust. But extensive land use and global warming can affect the biological crust. Calculations show that by 2070 the amount of dust in the atmosphere will increase by 15 percent. Dust in the atmosphere has different effects on the climate. High up in the atmosphere, dust reflects incoming sunlight, creating…
