For years, scientist have not only known that New Orleans is a sinking city but have judged its sink rate to be about 1/5 of an inch per year, on average. But now, new studies based on measurements taken from space suggest that 10 to 20 percent of the city is sinking as much as 1 full inch per year, which could prove disastrous if another large storm hits. No surprise, the causes include development and the destruction of marshland. Here’s the full story.