The $27 Billion Question
Can the Florida Keys adapt to sea level rise?
In a Nature Conservancy study on sea level rise, areas of Big Pine Key will be under water in a matter of decades. The second largest of the Florida Keys, Big Pine is best known as home to the Key deer.
Hurricanes Sandy and Irma demonstrated clearly how serious the risks of rising seas and storm surges are for land near sea level. Here in Florida, the Florida Keys tell the story of rising seas better than most places, with 90 percent of the land mass at five feet above sea level or less.
Homes, businesses, infrastructure and people, as well as natural areas and native species are affected by sea level rise today and may be impacted by storm surge at any time.
The Nature Conservancy recognizes this risk and has taken action, working with academics and federal, state, county and local government land managers, planners and elected officials on recommendations to address the problems.
Now the new coastal resilience map for Southeast Florida provides all the latest information to allow anyone to see it. Users select a base map or satellite photo and features of interest to see how they relate to sea level rise and a simulated storm surge using a future scenarios mapper.
“The Nature Conservancy wants nature and people to continue to coexist in the Keys for as long as possible,” says Chris Bergh, the Conservancy’s South Florida program manager based at the organization’s office on Big Pine Key. “This tool will help us do that by making it easier to visualize the risks involved and develop concrete plans to actively reduce those risks.”
Hurricane Irma in 2017 gave the Keys a painful taste of the future. “With Irma,” notes Bergh, “there was so much flooding from storm surge – so much property damage and impact on natural areas – that it was like a sudden preview of what sea level rise could do to the Keys. It got people thinking.”
To find out how much or how little margin there really might be for adapting to rising seas, a team of researchers in the Keys, led by Bergh, collected high-resolution elevation data of Big Pine Key and the best-available elevation data for the remainder of the Keys and combined that with the various projections of sea level rise prepared by the UN’s Intergovernmental Panel on Climate Change and others.
The results were startling: Even the most conservative scenario of a seven-inch rise in sea level by 2100 would equate to dramatic changes in habitat for plants and animals.
“It’s worth repeating that the projected sea level rise of seven inches is actually the most conservative scenario under the IPCC,” says Bergh.
Further refinement of the research in 2011 with even more detailed elevation data, led by Florida International University, shows the property value of the land at risk of inundation from 5 feet of sea level rise is about $27 billion with 56,000 residents and 76,000 acres impacted.
Bergh cites several studies, including the empirical evidence of the tide gauge at Key West, one of the longest continuous records of its kind in the U.S. Its collected data indicate that from 1913 to 2006, the sea rose about nine inches. Considering how quickly the world’s glaciers and ice sheets are melting, it seems, notes Bergh, “far more likely that sea level rise in the Keys –and around the globe - will be significantly higher in this century than the last.”
The Conservancy is particularly focused on making use of “green infrastructure” to minimize erosion and flooding.
“Coral reefs, mangroves, beaches and marshes help protect the islands and our communities at a fraction of the cost of seawalls, breakwaters and engineered stormwater management systems and with added benefits for fishing, diving and our tourism economy in general,” Bergh says. “We need to recognize the value of these natural features and continue to protect and restore them, and even move into actively creating them in some cases, so they can provide for us.”
This new tool will help people understand the individual and combined impacts of sea level rise and storm surge in the Keys by seeing it with their own eyes in map form.
For the coastalresilience.org future scenarios mapper, the Conservancy used the best available elevation data and added other features of interest, such as the ranges of protected species, infrastructure locations and critical facilities like hospitals. Users can model sea level rise of one foot to four feet, a simulated surge from a storm like Hurricane Wilma, or combinations of rise and surge. Practical plans can be developed with the help of the tool.
“We can move from the excellent general plans developed to date into the specifics, and identify exactly which stretches of road or which patch of Key deer habitat needs help, how much that help is going to cost, and how we are going to pay for it,” Bergh says.
Time to call the moving truck?
“Well, not quite,” says Bergh, who lives on Big Pine Key with his family. “These studies are about hope, not fear. Experience has shown that we can bounce back from hurricanes with the help of good planning, professional emergency managers, proactive elected officials and informed citizens who know what to do and when to do it in order to stay safe and recover quickly.”
The point is to make people aware of the magnitude of the challenge and encourage them to action while we still have time to act to reduce global greenhouse gas emissions and deforestation which would limit the amount of sea level rise and to develop and implement local plans to help nature and people resist and adapt to sea level rise.
“By using our community’s storm preparedness and response experience as a blueprint and The Nature Conservancy's coastalresilience.org website and future scenarios mapper to help fill in the details, we can show the world that the Florida Keys are ready for the challenge of sea level rise,” Bergh says.
“I’m optimistic,” he adds. “I'm putting an addition on my house so you can tell that I don’t think of this as impending doomsday for the Keys. We still have a chance to address climate change. We still have time to make changes. Nature – and people are part of nature – is very resilient. We can plan for change, and we can adapt if we want to and if we work hard enough.”