Stretching across northern Africa from the Atlantic to the Red Sea, it is the world's largest hot desert and covers about 9 million km².
Every year, about 27 million tons of dust blows from the Saharadesert across the Atlantic to the Amazon rainforest. The roughly 22,000 tons of phosphorus in this dust nearly matches what the Amazon loses to rain, making the world's driest place the fertilizer for its most lush.