USA: Anticipating sea level rise impacts on real estate investments

By Nik Steinberg, Director of Analytics at 427

What does the future hold?

New research on sea level rise emphasizes the potential for dire changes over the course of the century. Recent satellite data suggests that warming water is causing East Antarctica to melt more quickly than previously thought and a study released in early May found that almost a quarter of West Antarctica’s ice is thinning, with its largest glaciers shrinking five times faster than in 1992. A study based on expert opinion found that there is the possibility of sea levels rising by 2 meters (6.5ft) under an extreme scenario of 5˚C global temperature increase. This would mean an area of land as big as Libya would be lost, and up to 2.5% of the population globally could be displaced.

Extreme scenarios of sea level rise will have severe impacts on our cities and economies. Sea level rise is happening today to a lesser extent; however it is already having tangible impacts on real estate values. This means increasing costs for property owners and tenants, but it also has far-reaching market impacts on access to and cost of insurance, fluctuations in market values and potential increase in local taxes to fund adaptation efforts.

Of all U.S. states, Florida is expected to experience the greatest consequences of sea level rise. Between 1960 and 2015, sea levels along the Florida coast rose by 10-15 cm (4-6 in), and the range of projections vary wide looking a few decades out, with projections ranging from 33 to 122cm (13-48 in) by 2060.

Widespread flooding risk in Florida

65,000 homes in Florida worth $35 billion are expected to be underwater or impacted daily by high tides in 2040. From soaring insurance premiums and increasing risk of disclosure to declining property value and diminishing tax revenue, sea level rise is already challenging property owners, investors and banks. Among other impacts, the value of single-family homes in Miami-Dade County that are exposed to sea level rise declined by about $465 million between 2005 and 2016.

Furthermore, climate change is predicted to increase the number of strong hurricanes in the region. These stronger storms will combine with sea level rise to exacerbate the impacts of extreme floods. Storm surge flooding damages buildings and landscaping, destroys merchandise, and can also have wide-reaching economic impacts due to damaged power and transportation infrastructure.

Last but not least, tidal flooding, also called “nuisance” or “sunny day” flooding increased from 1.3 to 3 days per year in the Southeast from 2000-2015. By the end of the century tidal flooding could happen daily. Even with no rainfall, these floods have significant impacts – halting traffic, overburdening drainage systems and damaging infrastructure.

Investors and businesses have a responsibility to understand these risks: using best available science to measure exposure to sea level rise and other flood risks, getting informed on adaptation efforts by local governments, and engaging with local industry associations or other groups to promote further investments in resilience.