Rising sea levels will be too much, too fast for Florida

It is amazing for me to see the very aggressive building boom underway in south Florida; on the beaches and barrier islands, throughout downtown and in the low western areas bordering the Everglades. They are building like there is no tomorrow. Unfortunately, they are right.

The U.S. National Oceanic and Atmospheric Administration (NOAA) published its assessment of sea level rise in 2012 as part of the National Climate Assessment. Including estimates based on limited and maximum melt of the Greenland and Antarctic ice sheets, it anticipated a raise of 4.1 to 6.6ft (1.25 to 2m) by 2100, reaching 2ft (0.6m) by around 2050 and 3ft (0.9m) by around 2075.

This degree of sea level rise would make nearly all the barrier islands of the world uninhabitable, inundate a major portion of the world’s deltas, upon which hundreds of millions of people live, and leave low-lying coastal zones like southeast Florida increasingly difficult to maintain infrastructure services for and increasingly vulnerable to hurricanes and storms.

Most models of projected sea level rise assume a gradual acceleration of sea level in line with gradually accelerating ice melt. But our knowledge of how sea level rose in the past paints a very different picture of response to climate change.

At the peak of the last ice age 18,000 years ago sea level was some 420ft (128m) lower due to the vast quantities of water locked away in continental ice sheets. Subsequent ice melt was not a gradual process, but rather a series of very rapid pulses of sea level rise interspersed with pauses in which coastal environments formed. During pulses the seas rose between 3-30ft (0.9-9m) fast enough to drown not just reefs, sandy barrier islands, tidal inlets and other coastal features, stranding their remnants across the continental shelf, now disappeared beneath the ocean.