This 2017 study—Migration induced by sea-level rise could reshape the US population landscape—found that 13 million Americans could be forced to move by 2100. According to a study by the National Oceanic and Atmospheric Administration—2022 Sea Level Rise Technical Report—many U.S. coastal cities will be drowned by 42 to 84 inches of rise by the end of the century if global average temperatures rise by 2° Celsius (3.6° Fahrenheit) above pre-industrial levels. Based on pledges countries have made to cut their greenhouse gas emissions, global warming now has us on a trajectory to hit 2.8°C (5°F) by 2100, according to the 2022 U.N. Emissions Gap Report. That, scientists say, would be horrific. And policies in most nations aren’t adequate to fulfill their emissions pledges.
Another study was published Monday—Modes of climate mobility under sea-level rise in the journal Environmental Research Letters. It found that sea-level rise could displace up to 56% of households in Miami-Dade County, with the 2.6 million residents in the region experiencing “climate gentrification.” Like gentrification that has nothing to do with cliimate, the situation in Miami will have a negative, disproportionate impact on already marginalized communities.
In an interview with Minho Kim at ClimateWire (paywall), Nadia Seeteram, the lead author of the study, said: “Markets are aligning with the idea that there is a higher flood risk in these lower lying areas. The areas that happened to be gentrifying also happened to be among some of the higher-elevated areas” and are “homes to historically marginalized communities.” For instance, many minority neighborhoods with lower income levels are situated at higher elevations than rich beachfront areas. Miami’s famous Little Haiti neighborhood, where nearly half the residents live below the poverty line, is 10 feet above sea level and has experienced a recent surge in development and property values.
If the sea rises 40 inches (102 centimeters), about 19% of Miami-Dade County residents will be “stable,” 7% will be “migrating,” 18% will be “trapped,” unable to relocate, with the remaining 56% “displaced” because of rising housing costs as people move out of flood-prone areas. If the sea rises 80 inches (2 meters) nearly half of the Miami-Dade population will be “trapped” and 25% will be “displaced,” the study found. Only 8% will remain “stable” and 18% will be “migrating.”
The map below shows flooding exposure in Miami-Dade County. Click below for more readable version:
Excerpt from the study:
Estimates of displacement induced by sea-level rise (SLR) range from 88 M to 1.4 B people globally by 2100, depending on whether the estimates assess permanent inundation or consequences for low-elevation coastal zones as a whole (Nicholls et al 2011, Neumann et al 2015, Hauer et al 2016, 2020, Kulp and Strauss 2019, Oppenheimer et al 2019). The definitions of who is 'at-risk' focus on exposure to SLR and related hazards (Hauer et al 2020, McMichael et al 2020), which in addition to permanent inundation of land can include flooding from tidal, precipitation, groundwater, coastal storm surges, and compound events (Oppenheimer et al 2019, Jane et al 2020, Kirezci et al 2020, Tellman et al 2021). However, social and economic risks may extend to communities substantially beyond flooded areas as the spatiotemporal dynamics of flood risks are realized through housing markets, insurance and risk-transfer mechanisms, and adaptation investments. Notably 'climate gentrification' (Keenan et al 2018, Robinson et al 2020) and affordable housing shortages (Buchanan et al 2020) can result from increasing demand for housing in safer areas. Furthermore, disaster-related displacement (Myers et al 2008, Gray and Mueller 2012) and declining property values and household wealth from SLR and extreme flooding have the potential to exacerbate existing social inequity. Our understanding of how SLR affects communities should therefore include direct impacts of coastal flooding and indirect impacts (e.g. the increased demand for housing in safer areas), both of which may contribute to climate-related movement, or climate mobilities, and are important in determining the scale and nature of SLR impacts (Boas et al 2019, Wiegel et al 2019, Wrathall et al 2019). Climate mobilities will occur where risks are intolerable and other adaptation options are inadequate across varying community needs.
Policies to facilitate movement away from high-risk coastal areas are emerging (McLeman and Smit 2006, Bardsley and Hugo 2010, Black et al 2011a), but have yet to be designed with a capacity to anticipate the indirect impacts from market forces that are particularly important from an equity perspective. [...]
Our municipal-level assessment highlights the degree to which municipalities may face risks of depopulation and insolvency in the future, as climate mobility pressures vary across MDC municipalities for present-day (figure 6(a)) and future SLR (figures 6(b)–(d)). Consistent with the county-wide results (figure 5), figure 6(a) shows most municipalities clustered in the Displaced quadrant (upper left) with only one municipality (Key Biscayne) with 50%or more of its total population exposed to flooding or inundation. By 1 m of SLR, 9 municipalities have 50% or more of their total populations exposed to flooding or inundation, including vulnerable populations in Aventura and Miami Beach (Trapped), and significant populations in lower vulnerability municipalities such as Bay Harbor Islands and Golden Beach (Migrating; figure 6(b)). However, by 2 m of SLR,27 out of the 34 municipalities in MDC, along with Unincorporated Miami-Dade, have 50% or more of their total populations exposed to flooding, with 17 municipalities categorized with primarily Trapped populations.
How we go about mitigating sea level rise’s impacts given the disproportionate effects they will present is yet to be decided. We can be sure that the government cannot afford to do for all of Miami Dade’s vulnerable population what the National Park Service recently did in the Outer Banks of North Carolina:
After spending more than $700,000 for [two] salt-sprayed vacation homes [in Rodanthe, N.C.], the federal government plans to promptly tear them down and turn the area into a public beach access.
The move marks a unique and possibly groundbreaking chapter in the deepening dilemma of what to do with imperiled coastal homes, which are becoming only more vulnerable amid rising seas, more intense storms and unceasing erosion.
Some other readings:
And we shouldn’t forget that humans are not the only species that will be displaced: