Florida
While most of the world’s landmasses are millions, if not billions of years old, the ephemeral Florida Keys emerged from the waves only a few thousand years ago. If projections of rising sea levels are borne out, the island chain could disappear again within the next century.
In aerial views, the Keys are distinctive, swinging in a gentle arc for 120 miles south and west of the southern tip of Florida. Today there are 882 charted islands in the chain, but only a few dozen are inhabited, connected by the wave top–skimming Overseas Highway that runs from Key Largo in the northeast to Key West in the southwest.
The story of the Florida Keys begins in the Pleistocene Epoch, after enough marine sediment had accumulated on the seafloor south of Florida to result in a platform sufficiently high for sunlight to reach. Sunlight was the main ingredient needed for corals to colonize the underwater platform and create a reef out of their calcium carbonate skeletons. The Keys’ coral reefs were built up by elkhorn, staghorn, and star corals until around 100,000 years ago, when the planet’s ice caps began expanding, taking up seawater and lowering sea levels by as much as 300 feet. The Keys have remained above the waves ever since, gradually accumulating soil, plants, and animals, such as the diminutive Key deer, which lives only in this unique island setting.
Nearly 80,000 people live in the Keys (the Conch Republic to locals). About a third of the population lives in Key West, the largest town and last inhabited island in the chain. The Conch Republic may not be around for much longer, though. Sea levels have been rising since the Last Glacial Maximum (when glacial ice sheets were at their greatest extension) around 10,000 years ago, by an average of about twenty-four inches every 1000 years. Largely as a result of climate change, rates have been accelerating in the last century; some tide gauges in the Keys have recorded an alarming rise of just over a tenth of an inch per year.
A multitude of small islands make up the Keys island chain, including more than 850 that are uninhabited.
In 2013, the Intergovernmental Panel on Climate Change projected that sea levels would rise between ten and thirty-two inches by 2100. Other studies have projected an even more dramatic rise. According to the Nature Conservancy, even a conservative sea level rise estimate of seven inches by 2100 would mean the loss of about ninety of the Keys’ 240 square miles of land, while the more extreme projections of sea level rise would put all the Florida Keys underwater in the next century.
You might fly over the Florida Keys en route to Miami or Fort Lauderdale, Florida. Look for an island chain arcing off the southern tip of Florida.
