Coastal Louisiana Is Sinking Faster Than Expected
The rich wetlands of southern Louisiana are sinking faster than previously thought, new data reveals, worsening a decades-long ecological disaster that authorities are struggling to reverse.
Periodic flooding of the Mississippi River used to dump fresh soil into those marshes, bolstering the wetlands. But the levees that now prevent those floods keep that soil straitjacketed in the river. The area is also home to a major oil and natural gas industry, and canals cut through the marshes allowed salt water to kill grasses that held the land in place.
Sea levels are currently rising around 3 mm a year, but that rate is believed to be accelerating because of climate change. Warmer water expands, while melting glaciers and ice sheets in Greenland and Antarctica are expected to contribute more to sea levels in coming decades.