Sea rise and development increase hurricane threat
Florida study based on damage from Irma
MIAMI— Sea rise and development have put more Florida property at risk to hurricane storm surge flooding — about 43 per cent more — according to a recent study that looked at Hurricane Irma’s effect with different sea levels. NOAA Tidal gauges in Key West show that South Florida has seen about 18 centimetres of sea level rise since the 1970s, which is part of the reason sunny-day flooding has worsened in recent decades.
But when a hurricane blows through, that extra water becomes an even greater liability. Storm winds whip the water into buildings, busting through doors and swirling the contents of homes (or washing them away altogether.) Storm surge from Hurricane Irma alone affected 133,000 homes across Florida as the storm crawled up the spine of the state.
According to an analysis by First Street Foundation, that 18 centimetres of sea rise, plus an explosion of coastal development over the past decades, led Irma to swamp 57,000 extra homes.
If development along the Florida coast had been frozen in 1970s, the 18 centimetres of additional sea rise would have affected 35,000 more homes.
That pace of development doesn’t appear to be slowing anytime soon, nor does the rate of sea rise. Projections by the Southeast Florida Climate Compact, on which four South Florida counties base some of their decision making, predict 28 to 50 centimetres of sea rise from 1992 levels by 2050.
First Street chose the higher end of the curve, which is about 38 centimetres higher than today’s sea levels. With that much sea rise, another 200,000 Florida homes would have been swamped by Hurricane Irma, and that doesn’t account for increased development.
Scientists are “very confident” that climate change will make storm surge and rainfall worse, said Brian Soden, a professor of atmospheric sciences at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science.