Greenhouse gas might green up the desert

Missing: around 7 billion tons of carbon dioxide (CO2), the main greenhouse gas charged with global warming. Every year, industry releases about 22 billion tons of carbon dioxide into the atmosphere. And every year, when scientists measure the rise of carbon dioxide in the atmosphere, it doesn?t add up ? about half goes missing. Figuring in the amount that could be soaked up by oceans, some 7 billion tons still remain unaccounted for. Now, a study conducted at the edge of Israel?s Negev Desert has come up with what might be a piece of the puzzle.