Population growth and sea-level rise on a collision course in Florida: Consequences for biodiversity and ecosystem services

Background/Question/Methods

The threat of sea-level rise to people and nature in Florida is compounded by rapid growth of the human population and associated urban development. The vast majority (80%) of Floridians live or work in coastal counties. The National Climate Assessment (2014) concluded that Florida cities such as Miami, Tampa, and Fort Lauderdale are particularly vulnerable to sea-level rise, which has already resulted in extreme high tides and flooding, beach erosion, loss of coastal vegetation that buffers human communities from storms, and storm damage costing hundreds of millions to billions of dollars. Insurance analysts predict that portions of Florida could become uninsurable by 2100. Yet Florida’s population keeps growing. In 2014 Florida surpassed New York to become the nation’s third most populous state. We assessed potential combined impacts of sea-level rise and urbanization to imperiled species and natural communities in Florida to the years 2060 and 2100. We evaluated vulnerability and conservation priority of >300 species considering sea-level rise and interacting threats (especially urbanization), using multiple criteria. We projected human population growth and distribution to year 2060 with 1 meter of sea-level rise, with population displaced by sea-level rise reallocated statewide.

Results/Conclusions

Change in population in Florida is strongly and positively associated with change in GDP, with economic growth fueling population growth and vice versa. Population growth is resurging in Florida, with much of it concentrated in coastal counties. Many of Florida’s imperiled species are coastal in distribution and highly vulnerable to sea-level rise and “coastal squeeze,” the reduction of land area trapped between rising sea levels and urban development. The species most vulnerable to sea-level rise and urbanization are primarily endemic taxa on islands; for most of these species, the only alternative to extinction may be ex situ conservation. Many mainland coastal taxa are also highly vulnerable, especially on urbanized coastlines. Coastal ecosystems, such as salt marsh and mangroves, threatened by sea-level rise offer benefits to human communities by providing ecosystem services such as storm surge buffering. Loss of these ecosystems compounds the risk to human communities. As Florida’s population ultimately relocates inland, natural communities there will be more threatened by development. Any solution to the problems posed by urbanization and sea-level rise in Florida must involve policies to reduce population growth and to protect and restore coastal ecosystems for the benefit of people, property, and the natural ecosystems themselves.