“At the heart of the story is the fact that the Louisiana coastline loses land at a rate equivalent to a football field each hour. That comes to 16 square miles per year. The land south of New Orleans has always been low-lying, but since the Army Corps of Engineers built levees along the Mississippi after the huge 1927 floods, the delta has been losing ground. Previously, the river carried sediment down and deposited it to gradually build up dry land throughout the delta. The same levees that protect upstream communities also block that sediment from reaching the upstream river and floating down to become Louisiana coastline. Environmental researchers say that the energy industry’s canal-dredging and well-drilling have accelerated natural erosion. Together, the constricted river and the oil extraction have exacerbated the effect of sea level rises from climate change. The loss of ground endangers people: The dry land used to provide protection to New Orleans’ people and businesses, because when storms like Hurricane Katrina sweep in from the Gulf Coast, they lose power as they move from the water to land. It’s therefore crucial to have a wide buffer between the sea and the city. Now, with 2,000 fewer acres of protective land, the state will have to spend more money building tougher, higher walls, flood insurance will be more costly, infrastructure could break and the people inside those walls risk death and injury at much higher rates. If the land-loss isn’t slowed the costs will get higher.”