Climate Change and Sea Level Rise in South Florida


This week on Waterways; Global climate change and rising sea levels in south Florida. Florida’s coastline beckons people from all over the country, and the world. A beachfront home in Florida; a vacation spot on a Key West canal; a Miami waterfront condominium; Being close to the water is very desirable for many people. The closer to the water, the more valuable the property. But Florida is disappearing. Sea level rise is submerging the coastal communities of Florida, and jeopardizing investments and the state economy. Along with the personal and financial loss of property, comes a loss of habitat and wildlife. Climate change is real and is impacting the people and the landscape of south Florida. In the past there were some fairly dramatic periods of sea level rise that caused the native Americans and other indigenous people around the world to rapidly and dramatically change where they lived and move inland and upslope. But again, for the last 3 thousand years or so, the sea level has been quite stable and we have moved into the shore and invested and built our homes started our businesses and built all this infrastructure, everything from roads to bridges and power lines and everything else which makes our modern society possible.

But relatively recently, the trend in sea level rise has been a rapid acceleration. Between 1000 BC and the year 1900 sea level rose about one-and-a-half inches every 100 years. In Florida, in the past 100 years alone, sea level has risen more than 8 inches. The National Oceanic and Atmospheric Administration, or “NOAA” the leading U.S. agency studying climate change and sea level rise estimates global sea level will rise between 8 to 80 inches by 2100. The exact amount will be determined by the amount of ice sheet losses and increases in ocean warming. Under the worst case scenario, by the year 2100, 56% of developed area in south Florida could be under water at high tide. Early in the morning of Monday, October 24th, 2005, the people of south Florida huddled inside homes and hurricane shelters, bracing themselves for the thirteenth hurricane in a record-breaking storm season.

Hurricane Wilma had reached Category 5 strength winds, but by the time it passed the Florida Keys, the storm was downgraded to a category 3. Wind gusts up to 120 mph wreaked havoc in the Keys, but it was the flooding after the storm that caused the most damage. Not since Hurricane Betsy in 1965 had the Keys faced such drastic flooding. We got interested in sea level rise, when hurricane Wilma in 2005 flooded almost the entire Florida Keys with seawater. And Big Pine Key, where we’re now sitting was no exception. In fact, my yard was under water by about 2 feet, and we were able to see what and visualize what sea level rise would look like, for the first time. Though the eye of Hurricane Wilma passed just north of the Keys, sparing the island chain from the highest winds and heaviest rains, the ocean surrounding the islands rose quickly, inundating many island communities in two to three feet of water in less than 15 minutes. Coastal flooding in Key West typically occurs when water levels reach 3 ft above mean sea level. When storm tides for Wilma reached up to 6.5 ft above sea level, almost the entire eastern half of Key West was under water.

In 2007, Chris Bergh of The Nature Conservancy initiated a research project to identify impacts of sea level rise in the Florida Keys. They created digital models illustrating sea level rise scenarios from 7 inches to 4.6 feet to reflect the best available range of sea level rise for the year 2100. We got very concerned about it and we decided we should take a look at the elevation of the islands in the Florida Keys and then use what is called “Bathtub Modeling” to digitally using computer simulations, artificially raise the elevation of the ocean by different increments. Since more than ninety percent of the Keys’ land area is less than five feet above sea level, scenario mapping tools helps illustrate the potential dangers facing our communities from rising sea levels. The Conservancy’s online mapping tool available at enables web users to simulate what Big Pine Key, in the middle Florida Keys, would look like with a sea level rise of one to four feet, or simulate a storm surge such as the one from Hurricane Wilma, or a combination of both rise and surge. The mapping tool uses real world elevation data, along with infrastructure locations, facilities like hospitals and the habitat ranges of protected species.

You look at South Florida or anywhere else, you say, “Oh, we’ll move inland.” Well, maybe some places you can move inland, South Florida, we have the Everglades. The farther inland we get, the lower it gets, so we’re going to lose, we’re going to lose it all this century. Sea level is rising because the atmosphere and the ocean are warming. The Earth is warming because of greenhouse gases. In 1824, French mathematician and physicist, Joseph Fourier, discovered that some gases trap heat within the earth’s atmosphere. These gases, like methane and carbon dioxide, are called “green-house” gases. Without greenhouse gases, life on Earth would be far too cold. Greenhouse gases keep the sun’s heat from bouncing back into space.

But through human activity, the amount of greenhouse gases in our atmosphere has soared. Through the burning of fossil fuels- such as coal, oil and natural gas- approximately ten billion tons of CO2 are added to the atmosphere every year. However, only six to seven billion tons of CO2 are removed from the atmosphere by plants and oceans. More CO2 is entering the atmosphere than is being removed. This imbalance is the fundamental cause of our accelerated climate change. For more than 100 years, NOAA has been monitoring rising sea levels with tidal gauges that pepper America’s coastline. NOAA also operates environmental satellites that perpetually monitor the planet. Data from these satellites is used to measure numerous environmental factors including the sea surface temperature of the ocean, an indicator of climate change. According to NOAA data, 2012 was the warmest year ever recorded in the US since record keeping began in 1895. The latest climate projections call for the globe to warm between 3.2°F and 7.

2°F by 2100, depending on the amount of future greenhouse gas emissions. As the atmosphere gets hotter, ocean temperatures also increase, and warmer water has a greater volume than cooler water. So as the ocean heats up, it gets larger, and sea level rises. The warming of the ocean will maybe add nearly another foot this century. The melting of the Alpine Glaciers, which is dramatic, that may add another 8 or 9 inches this century. But the huge potential for the sea level rise is the melting of the ice sheet. Greenland has enough ice, that if it all melted, it could raise sea level by 23-24 feet. The West Antarctic ice sheet alone has enough ice to raise sea level by 25 feet. While the world’s ice sheets won’t totally disappear by the end of the century, they are melting at an alarming pace. Single weather events can’t be directly linked to climate change. A study published by the Proceedings of the National Academy of Sciences, estimates that for every 1.8°F increase in global temperatures, there could be up to a seven-fold increase in the risk of extreme storm surge events.

There’s a common misperception about differences between “climate” and “weather”, so weather is what’s happening now. Right now, it’s a little bit windy and it’s a little bit cool and not a cloud in the sky that’s the conditions at the moment. And “climate” is the trend over decades or centuries. So, in order for me to say that the climate has changed here, I would have to have these relatively windy, relatively cool, relatively dry conditions for many, many, many days, weeks, months, and years on end before I could say that the climate is trending towards cool and dry and windy. You know, one snowstorm or one hurricane or one windy day does not make climate change. But when those things multiply themselves and the trends change, that’s climate. The crisis we face was once called Global Warming”. And while the atmosphere and oceans are warming, it’s more accurate to call the phenomenon “Global Climate Change”. Some places may get more rain and floods.

While other places may see more heat waves and droughts. But everywhere, the waters will be rising. Cape Sable is the southernmost point in the United States mainland and covers the western portion of Everglades National Park. Scientists have been studying Cape Sable for years and tracking the changes caused by climate change. Since the 1930’s, we have been measuring and studying what’s happening at Cape Sable. And it is a really awesome place, not only for science but to visit. The scientists love Cape Sable because it is an undeveloped part of Florida, which you can compare directly to developed parts of Miami. What we have seen happening at Cape Sable since the 1930’s, is sea level is rising and up to 80 times a year now, high tides are pushing over the marl ridge line and salt water is now pushing into what used to be a fresh water lagoon. Fifty to sixty percent of land-based Everglades National Park is below 3 feet in elevation. This wild place where plants and animals rely on healthy freshwater flow for survival is facing an inundation of salt water. When we think about the animals and the plants that will be affected by the sea level rise along Cape Sable, we’re going to be thinking a lot about some of the plants that are unable to migrate or move.

Birds, perhaps, can move somewhere else, as long as they can still find habitat and food, and perhaps that’s saving grace for the endangered Cape Sable Seaside Sparrow. But there’re gonna be plants that are unable to migrate quicker than the sea level is rising. We already see the mangroves are marching inland; and that’s because the sea level is rising, the salt water is overtopping some of the natural barriers. The mangroves are moving inland as the sea level rises. If mangroves are moving in, they’re obviously displacing some habitat. So the salt water tolerant mangroves, they’re displacing the fresh water habitats, like the pinelands, the Cypress areas, and the fresh water sawgrass prairie. One thing that might slow this salt water intrusion into the freshwater Everglades is the implementation of Comprehensive Everglades Restoration Plan, or CERP, which is a 30-year project to restore a more natural water flow across central and south Florida and throughout the Everglades.

So, there’s a lot less fresh water pushing south and if we can restore the flow of clean, fresh water from the north part of the Everglades through Lake Okeechobee, down the Florida Bay and the other southern estuaries, that fresh water will actually help push back the encroachment of salt water into the southern Everglades, into the saw grass marshes and low-lying areas of the southern Everglades. So the more fresh water there is flowing south, the longer the Everglades will persist as we know it. Achieving the right timing, quantity, quality and distribution of freshwater through the Everglades is essential for the survival of this national park and the flora and fauna that call the whole Everglades region home. The pulse of fresh water coming into the Everglades for half of the year, means that the entire ecosystem is dependent on the timing and the quality of this fresh water.

If there is changes in the arrival of this fresh water through the dry season or there’s changes in the wet season, that will have a direct impact on the environment. Changes in precipita;tion patterns are projected due to climate change; also predicted, greater swings in the weather. Highs may become higher, and lows become lower, andthese extremes may last longer. There may be longer periods between rain events, and more intense storms when they finally arrive. We are seeing things like significant cold spells that do affect the wild life, the fish in Florida Bay and the fish kills. We’re also seeing the flip side of that, warmer, excessive warm temperatures in areas, we saw algal blooms and some fish kills that resulted from higher than normal temperatures. Rising sea levels and more extreme weather events are not the only dangers; warmer waters can cause widespread coral bleaching or die-offs,; changes in ocean chemistry can impede coral skeleton and shell development in marine life; some areas will see larger and more frequent wildfires; and mountains could lose their snow packs. Some plants are expanding or shifting their habitat range, and others are flowering earlier in the year because of warming.

This may lead to migrating birds arriving out of synch with vital food supplies. Some people point out that the earth has a history of natural heating and cooling even before modern humans existed. It’s true that there are natural cycles; but the speed at which the environment is changing is what challenges the vitality and even the existence of many plant and animal species. It makes you think, long term, about conservation strategies like land acquisition. It makes you think about instead of just trying to buy all the land that is important for wild life to buying corridors that would allow wildlife to move from the low lying areas to the highest ground. And it fundamentally made us rethink everything about our conservation strategies in the Florida Keys. There are two approaches to dealing with the effects of climate change: mitigation and adaptation.

Both approaches will be necessary for dealing with our changing world. There may be technology developed in the future that could remove carbon dioxide and other greenhouse gases from the atmosphere, but we cannot wait for a “silver bullet”. We must protect and restore the natural systems that remove carbon dioxide from the atmosphere and oceans. Coral reefs, mangroves, marshes, seagrass beds, forests and grasslands all absorb carbon dioxide. Conservation of these areas contributes to slowing down the changes ahead and directly benefits all of us. Everything’s happening faster, and, you know, back in 2000, I wasn’t sure how much I would see of global warming in my lifetime. But NOW, I’m wondering if I should be living where I am because I’m in beautiful Coral Gables at 11 feet above sea level, far from the ocean but not far from the effect of sea level rise. We will see sea level rise, we will have to adapt.

So, everybody needs to get informed about this issue and make decisions today with an eye to the future. Sea level rise will affect roads, railroads, airports, seaports, and pipelines. The cost for rebuilding will reach hundreds of billions of dollars if we cannot find a way to adapt. Can we be smarter when we rebuild? Can we adapt our cities? What can we do to our house or an apartment building so that the generators aren’t on the bottom floor. Can we be putting more gardens on a rooftop instead of a heat-absorbing black top? These are engineering questions. These are questions for the community and for individuals. For the Florida Keys, adaptation will be more difficult than other places. A lot of people think that the solution to sea level rise is relatively straightforward. They say: “Hey, just do what Holland did, or do what New Orleans did, and put up a dike around the Florida Keys to keep the sea out.

The problem with that is that sea is not only surrounding the Florida Keys, it’s actually under the Keys as well. And the rock that our island are made of is like a Swiss cheese or a sponge. It’s full of holes, even if you put up a dike around the islands, the water would still rise from underneath our very feet through that porous limestone rock that we all live on. Scientists with NOAA and other agencies are collecting data to quantify and assess how and where climate conditions have changed. This information will help predict future changes, and improve climate models for regional and local decision making. What we’re trying to do more of is to be more is to be more predictive and so we are working with a lot of our other scientists and collaborators to develop predictive models and some other tools that help us to understand what we might be faced with in the next 20 years, 50 years so we can start incorporating that information into our planning process. Our ability to collect information to see what’s happening out there on the landscape at any point in time, and then make appropriate changes in our management strategies to address our resources in the conservation, is going to be critical to insure that we can fulfill our mission and really protect all these great resources that we have.

What is happening here in south Florida is happening everywhere on the planet. Half the world’s population lives within 60 miles of the coast; just about 3 to 6 feet above sea level. The most important lesson to remember is that we can all make a difference. One of the things the Park Service is trying to do is instill the realization that it is a human caused issue and climate change will have human solutions. And that is where individuals have the opportunity to make a difference. An individual can make changes in his or her lifestyle. A small step can go a long way when a lot of people are doing it. I think the simplest thing to do is to just to start to learn about the issue; think of ways that you can act and be a part of the solution. A lot of people that I know are thinking about and are actively trying to reduce their carbon footprint. We car pool; we make decisions about what vehicles we buy; we buy carbon off-sets if we go for a flight somewhere. Solar panels; insulation; turning off lights when leaving a room.

There are hundreds of seemingly trivial ways we can reduce our carbon footprint. Am I optimistic? I’m optimistic when I talk to the kids. I have faith. Absolutely! It’s a human caused problem; there will be a human solution. For more information on climate change and how you can help do your part, visit, and