Sea levels have been rising for thousands of years, but today, they are swelling at an unprecedented rate. By the end of the century, modest projections predict that seas will rise at least another 0.5 meter—the same amount as over the last two millennia. The year 2100 is often perceived as a tipping point for when rising seas will set a “new normal” where frequent floods occur along coasts. However, according to the work of Sweet and Park that tipping point may arrive even sooner.
As rising waters swallow up more and more land, flooding has become a significant problem in coastal communities. Nuisance flooding—floods between 0.3 and 0.6 meter—is 5 to 10 times more likely today than it was 50 years ago. The authors combined climate projections of global sea level rise, based on data from National Oceanic and Atmospheric Administration tidal stations with at least 60 years of records, with regional factors such as land subsidence and interannual variability in El Niño to show that the frequency of nuisance flooding events in the United States is rising much faster than average sea levels.
If the trend continues, the authors say that by 2050, many cities along the Mid-Atlantic, Gulf, and West coasts will experience 30 or more days with nuisance flooding a year. By the end of the century, nearly all the locations the study examined may face minor flood events on a daily basis. This “new normal” has major implications for local governments and organizations responsible for building resilient coastal communities. The projected minor, nuisance floods may not be catastrophic, but they can still be damaging and costly. (Earth’s Future, doi:10.1002/2014EF000272, 2014)
—Kate Wheeling, Freelance Writer
Citation: Wheeling, K. (2015), Tipping point for nuisance coastal flooding may come by 2050, Eos, 96, doi:10.1029/2015EO027807. Published on 10 April 2015.