Q. Who says the sea level is rising and affecting South Florida?
Most climate scientists, many South Florida government officials and even some business leaders. You also can check with your neighbors who are watching streets flood on sunny days and seeing water creep higher and higher into their yards during storms and king tides.
Ben Strauss writes this for Climate Central: “In South Florida, taxpayers are already paying the price for climate change as salt water pushes through porous bedrock into coastal drinking-water supplies, and rivers and canals choked by heavy rains have a harder time draining into the ocean.”
“A recent Florida Atlantic University study estimated that just 6 more inches of sea level rise — very plausible within two decades — would cripple about half of South Florida’s flood control capacity. It’s now, not later, for sea level rise in South Florida.”
Q. Is anyone addressing the problem?
South Florida governments in 2010 formed the Southeast Florida Regional Climate Change Compact to address the inevitable rise. Here is what the Compact’s experts say:
“Southeast Florida, along with the nation, is seeing multiple impacts of climate change firsthand, such as sunny-day flooding, extreme rain events, and record-breaking temperatures as sea levels rise by a projected 6-12 inches in the next 15 years.”
Q. Has the sea level been rising in recent years?
Yes. South Florida’s sea level rose about 8 inches during the 20th century. Scientists attribute most of that rise to the warming of the planet. With more greenhouse gases trapped in the atmosphere and more being released each day, scientists predict the rate of rise will accelerate.
Q. Why is the sea rising?
The planet is getting warmer. When that happens, the oceans get hotter. When water warms up, it expands.
Also, as the planet gets warmer, huge amounts of ice melt. As ice sheets and glaciers melt into the oceans, the water rises. An enormous amount of ice has melted into the oceans in recent years and it appears that trend will continue.
Finally, as the climate changes, the flow of the Gulf Stream slows. This slowing also causes the Atlantic Ocean along Florida’s coast to rise.
Q. Why is the planet getting warmer?
While it’s true global temperatures have gone up and down over the centuries, the world has never experienced a continuous increase like the one currently taking place. Most scientists who study this issue attribute the rapid warming to human activities that emit substantial amounts of carbon dioxide into the atmosphere. The CO2 and other greenhouse gases trap heat in the atmosphere that normally would dissipate. The captured heat warms the planet. Research shows that much of the carbon now trapped in the atmosphere comes from the burning of fossil fuels.
Q. Some federal and state government officials don’t believe that burning fossil fuels is a primary contributor to global warming. Why do they doubt this science?
There’s a spectrum of skepticism. Some say climate change is a “Chinese hoax.” Others say the science is unproven and more research is needed. Some acknowledge that the climate is warming, but say human activity is not the cause.
Critics of these politicians say many are simply trying to protect the fossil fuel industry. They dislike the regulations that governments have imposed on businesses to curb the emission of greenhouse gases. Those regulations, they claim, are hampering economic growth. Many complain that countries like China and India are burning more fossil fuels than ever and are doing little to curb their use.
“Scientists worldwide agree that global warming is happening and human activity causes it,” according to the Union of Concerned Scientists.
Q. If we stop putting any CO2 in the atmosphere right now, would that stop sea-level rise?
No. The authors of “Florida’s Climate,” published by the Florida Climate Institute, say, “…some people assume if we were to suddenly reduce emissions that the sea level would stop going up. We need to explain that if emissions are reduced to extremely small levels, it will still be a long time before the greenhouse gases already put into the atmosphere can be removed by natural processes.”
A 2017 report by the National Oceanic and Atmospheric Administration says: “…even if society sharply reduces emissions in the coming decades, sea level will most likely continue to rise for centuries.”
Q. Can we stop global warming or even reverse it?
Yes, in theory, if most of the world’s governments and companies get on board. Can we reverse it? That’s to be determined. Scientists are working on technology to remove CO2 from the air. [Here’s a story in the November issue of The New Yorker about technology that can take CO2 out of the air.]
There’s also been research on putting gas or other substances into the atmosphere to block some of the sun’s heat from reaching the earth.
What’s in development will take a lot of time and an enormous amount of money to implement, and there are also political and environmental concerns around tampering with the atmosphere. But potentially, geoengineering could be part of a solution to global warming.
Q. I just don’t believe that a place as large as Florida can sink under water. People have been living here a long time. Is there evidence that this can happen?
In geologic terms, Florida is a narrow piece of land surrounded by water. The state’s dry footprint has shrunk and expanded dramatically over that last 120,000 years. Here are details from a University of Florida study.
Q. How fast will the water rise in South Florida?
Officials with the Climate Compact – which is a collaboration of officials from Palm Beach, Broward, Miami-Dade and Monroe counties – provided this projection in 2015:
Sea level in South Florida will rise above the 1992 mean sea level this much:
- 6 to 10 inches by 2030
- 14 to 26 inches by 2060
- 31 to 61 inches by 2100
The Compact adopted the projections so that governments and businesses will have a common measuring stick when planning how to cope with the rising water.
Q. How reliable are those projections?
The Compact notes that projecting sea-level rise is an ongoing process that depends on whether the planet will continue to get hotter.
The Compact’s members are planning for more and quicker warming. The Compact’s report notes that ice sheets in Greenland and Antarctica “are more vulnerable to melting than previously realized.”
A study published Dec. 13, 2017 says that the melting of Antarctic ice shows that sea-level rise will double current projections “this century if global emissions of heat-trapping pollution remain high.”
Q. How should governments and businesses apply these estimates?
It depends on the project.
The Compact report recommends that anyone planning “high risk” projects should use the estimate produced by the National Oceanographic and Atmospheric Agency (NOAA). That agency projects the sea level to rise by 81 inches by 2100 – 20 inches higher than the consensus projection of 61 inches.
The report describes high-risk projects this way:
Projects “to be constructed after 2060 or projects which are not easily replaceable or removable, have a long design life (more than 50 years) or are critically interdependent with other infrastructure or services.”
Q. Will all this water cause any harm in South Florida?
Yes. Here is what the scientists who work for the Compact predict if the sea rises at the rate they predict:
- Coastal inundation of inland areas
- Increased frequency of flooding in vulnerable coastal areas
- Increased flooding in interior areas because the region’s stormwater infrastructure – gravity drainage systems and the region’s canals — will become less effective
- Saltwater intrusion into the aquifer and local water supply wells
- Contamination of the land and ocean with pollutants and debris and hazardous materials released by flooding
- People will move away
- Decrease in property values and tax base
- Higher insurance costs
- Loss of services and impaired access to infrastructure
Q. Does South Florida have strong flood infrastructure?
No. The region’s drainage system is 70 years old and many coastal flood-control structures won’t be able to handle a two-foot rise in sea level. In fact, some can’t cope with current high tides, according to the South Florida Water Management District.
Coastal floodgates have to stay closed when sea levels rise higher than the point where stormwater from drainage canals normally gets dumped into the sea.
Keeping those floodgates closed increases the flooding risk when drainage canals overflow. That will happen more and more.
When the SFWMD studied the problem in 2009, 20 flood control structures were deemed vulnerable if sea level rises just half a foot – which now is projected to happen in less than 15 years.
Q. Will people who live far from the coast be affected?
Yes. Overflowing canals can cause flooding in communities far from the coast. The vast system of levees, pumps and canals that keeps South Florida from flooding relies on draining water out to sea. If coastal floodgates can’t open, then canals inland will overflow.
Also, as saltwater moves inland, it’s pushing up the level of the freshwater table belowground. The freshwater seeps up through South Florida’s porous limestone, and leads to inland flooding in communities like Sweetwater.
Having a high water table also keeps rainwater from draining.
Q. What are “sunny day flooding” and “king tides”?
The effects of sea-level rise can be seen as coastal areas flood when there’s not a hurricane or even afternoon thunderstorm. This is “sunny day flooding” and it’s a fairly new phenomenon in South Florida.
Seasonal high tides, called king tides, occur in the fall when the moon comes closest to the earth and intensifies the usual gravitational push and pull on the ocean. These higher-than-usual high tides are rising, overwhelming seawalls and pushing ocean water onto streets, sidewalks and yards.
Miami Beach, the Lakes area in Hollywood, Las Olas Isles in Fort Lauderdale and the Marina district in Delray Beach are among the communities getting flooded by king tides.
Q. Are there any other flooding threats to South Florida?
Yes. Climate experts say that the same factors that are causing the seas to rise also are spawning larger and more frequent storms. A warmer atmosphere and seas provide storms with more energy. They say South Florida will have to cope with more hurricanes that will have higher winds and dump more water on the region.
Also, because the sea is higher, the storms will produce higher storm surge.
The Compact says: “Severe storms of the future will cause more damage than storms of equal intensity occurring at today’s sea level.”
Q. Will sea-level rise harm our supply of fresh water?
Yes. A recent Florida Atlantic University study says: “…increasing temperatures, and changing weather patterns threaten the quality and availability of South Florida’s drinking water sources.”
The rising seas “pose potential threats to human health” and will cause:
- Salt water intrusion to freshwater aquifers
- Septic tank leakage
- Soil saturation
Saltwater for decades has seeped in from the ocean and fouled South Florida’s underground drinking water supplies. Ninety percent of South Florida gets its drinking water from underground supplies, most from the Biscayne Aquifer.
Sea-level rise is expected to push saltwater intrusion farther inland. Water utilities will have to close more wellfields and spend millions finding new sources of drinking water.
That can include creating new wellfields farther inland or building water plants that can convert salt water into drinking water.
Hallandale Beach, Pompano Beach, Dania Beach, Lantana and Lake Worth are among cities that in recent years have had to close wells or curtail pumping because of saltwater intrusion.
The line of saltwater spreading inland already comes close to or reaches South Florida cities from Jupiter to Florida City, according to the U.S. Geological Survey.
Q. Will rising seas harm wildlife, the Everglades and other natural areas?
South Florida development and farming have already claimed half of the Everglades and now sea-level rise could wipe out the rest. Rising seas will increase coastal erosion on the southern end of the Everglades, reduce mangrove forests, scare away migrating wading birds, increase peat collapse and push more saltwater into freshwater marshes – killing fish and wildlife habitat.
This threat comes as the state and federal government are spending $16 billion on Everglades restoration.
Q. What effect will rising sea levels have on South Florida’s economy?
Right now, there’s very little effect. Tourism is strong. Housing prices continue to rise. Developers are building lots of commercial and residential projects. More and more people are moving here.
A March 2017 story in the Miami Herald reported that between 2010 and 2016, South Florida’s population grew by nearly 500,000, the 7th largest urban growth area in the country. The region now has more than 6 million residents and will have almost 9 million by 2050.
However, recent research from Harvard University and the University of Colorado suggests that in Miami-Dade County, “homes in lower elevations are selling for less and gaining value slower than similar ones at higher elevations,” according to the Miami Herald.
Q. Will my property values be affected?
Eventually, experts say. As flooding and storms worsen in the decades ahead, South Florida real estate will become less desirable. Also, insurance will become very expensive.
Right now, however, South Florida real estate is thriving. The Sun Sentinel reported this in July: “Home prices increased across South Florida in June and are inching ever closer to the peaks achieved before the market meltdown a decade ago.”
Q. Will the region be able to support 9 million people in 2050?
It depends, says Ben Kirtman, a professor of Atmospheric Sciences at the University of Miami. If governments and developers recognize the challenges of sea-level rise and build accordingly, then South Florida will be fairly dry and safe. If infrastructure is neglected and buildings poorly designed, the region will begin to decline, Kirtman says.
“If we aren’t careful, banks won’t loan the money to develop,” he said. “I worry what will happen if we make mistakes.”
Even if governments and developers do their best, Kirtman isn’t sure the region can accommodate 3 million more residents.
Q. How will sea-level rise affect flood insurance over the next 10 to 15 years?
Climate change and sea-level rise are increasing the risk of flooding. When risk increases, so does the cost of flood insurance, which is required if there is a mortgage on the property.
The National Flood Insurance Program is raising rates on all older pre-Flood Insurance Rate Map (FIRM) buildings to actuarial rates to reflect the increased risk of flooding. These buildings have enjoyed subsidized premium rates for more than 40 years.
At the current rate of increases, all pre-FIRM buildings that are not a primary residence will be at actuarial risk rating within 10 years. All pre-FIRM buildings that are primary residences will be at actuarial rates within 15 years.
Q. What happens after that?
It’s impossible to say. No one can accurately predict how much the sea will rise after 2060.
The Compact predicts the sea will rise 31 to 61 inches by 2100. If the sea rises 61 inches, much of South Florida will be under water. People will be living in buildings on stilts and using water-based transportation. With decades to adapt, some people may find living atop water a viable lifestyle.
But even if that’s the case, South Florida will be physically smaller and have fewer people.
Q. What is the South Florida Water Management District doing to respond to sea-level rise?
In 2008 the South Florida Water Management District agreed to take a harder look at sea-level rise in South Florida. District officials warned that if the sea level rose 2 feet, the vast system of canals that relies on gravity to drain water out to sea would not work.
A district plan outlined in 2010 called for buying more land for flood control and designing improvements for a 70-year-old drainage system.
The district determined that many flood-control structures needed upgrades to deal with rising seas. Work was supposed to begin by 2015, but has yet to get started.
Q. What is the Southeast Florida Climate Change Compact doing?
The Compact approved a plan that includes more than 100 recommendations for coping with rising seas, stronger storms and worsening flooding.
Measures in the plan include:
- Raising low-lying roads
- Restricting building in areas vulnerable to flooding
- Moving well fields farther inland.
- Promoting public transportation to reduce the pollution caused by motor vehicles
- Changing development guidelines to address the effects of climate change.
Q. Can South Florida survive – or even thrive – as the sea rises?
It depends on how high the water rises in the next 10, 40 and 80 years.
Let’s pick roughly 40 years. The Compact experts say the sea will rise 14 to 26 inches by 2060. If those estimates are correct, South Floridians have two choices: move away from chronically flooded areas or spend billions of dollars on pumps, pipes, canals and seawalls.
If residents and governments do nothing, then many parts of South Florida will be flooded regularly. The economy and property values will begin to collapse. People will move.
On the other hand, residents – through higher taxes and fees – could decide to pay to raise roads and improve drainage systems. Developers could raise the land they build on. Property owners could pay to raise their homes and seawalls.
Experts call these efforts “adaptation.” Most members of the Compact believe that if governments, businesses and residents spend the money to adapt, much of South Florida will be dry, comfortable and prosperous in 2060.
However, even the most aggressive adaptation won’t save every community. No matter how much governments spend to hold back the water, South Florida probably will have less habitable land by 2060 and fewer residents.