Miami and its surroundings are facing a calamity worthy of the Old Testament. Roughly a third of the U.S. population—more than 100 million people—live in coastal counties. Coastal states with large areas of low-lying land, including Louisiana, Florida, North Carolina, California, and South Carolina, are particularly vulnerable to rising seas and coastal storm surges. The risks to coastal states include: • Shoreline erosion and degradation. • Amplified storm surges. • Permanent inundation. What makes Miami exceptionally vulnerable to climate change is its unique geology. The city – and its satellite towns and resorts – is built on a dome of porous limestone which is soaking up the rising seawater, slowly filling up the city's foundations and then bubbling up through drains and pipes.