Some coastal cities are sinking faster than the ocean is rising

Coastal communities are facing a hidden threat that is making rising seas far more dangerous: the land beneath them is sinking. New research shows that people in densely populated coastal regions experience an average relative sea-level rise of about 6 millimeters per year, nearly three times the global coastal average. Groundwater pumping, oil and gas extraction, heavy urban development, sediment compaction, and natural geological processes are all contributing to the problem.