1 Before Hurricane Sandy tore through New York and New Jersey, it stopped in Florida. Huge waves covered beaches, swept over Fort Lauderdale's concrete sea wall and spilled onto A1A, Florida's coastal highway. A month later another series of violent storms hit south Florida, severely eroding Fort Lauderdale's beaches and a section of A1A. Workers are building a new sea wall, mending the highway and adding a couple of pedestrian bridges. Beach erosion forced Fort Lauderdale to buy sand from an inland mine in central Florida; the mine's soft, white sand stands out against the darker, grittier native variety.
2 Hurricanes and storms are nothing new for Florida. But as the oceans warm, hurricanes are growing more intense. To make matters worse, this is happening against a backdrop of sharply rising sea levels, turning what has been a seasonal annoyance into an existential threat.
3 For around 2,000 years sea levels remained relatively constant. Between 1880 and 2011, however, they rose by an average of 0.07 inches (1.8mm) a year, and between 1993 and 2011 the average was between 0.11 and 0.13 inches a year. In 2007 the Intergovernmental Panel on Climate Change (IPCC) forecast that seas could rise by as much as 23 inches by 2100, though since then many scientists have called that forecast conservative. Seas are also expected to warm up, which may make hurricanes and tropical storms more intense.
4 Even as seas have risen over the past century, Americans have rushed to build homes near the beach. Storms that lash the modern American coastline cause more economic damage than their predecessors because there is more to destroy. The Great Miami Hurricane of 1926, a Category 4 storm, caused $1 billion-worth of damage in current dollars. Were it to strike today the insured losses would be $125 billion, reckons Air Worldwide, a catastrophe-modelling firm. In 1992 Hurricane Andrew, a Category 5 storm, caused $23 billion in damage; today it would be twice that
5 Most Floridians live in coastal counties. Buildings cluster on low ground; more people than in any other state live on land less than four feet (1.2 metres) above the high-tide line. Florida's limestone bedrock makes it easy for salt water from surging seas to contaminate its freshwater aquifers. And it relies heavily on canals for flood control, which a sea-level rise of just six inches would devastate.
Adapted from The Economist, June 15th , 2013