EPA-430-F-02-007
March 2002
B See the U.S. Environmental Protection
Agency's Global Warming Site at
www.epa.gov/globalwarming.
I! For specific information about sea level
rise, see www.epa.gov/globalwairming/
sealevelrise.
B Contact the Florida Coastal Management
Program at 850-922-5438, or Florida Sea
Grant (Miami-Dade County) at 305-361-4017
or visit www.dca.state.fl.us/ffcm/.
B For information on flood insurance, call
800-480-2520 and ask for a booklet titled
"Answers to Questions About the National
Flood Insurance Program."
H Miami-Dade County Department of
Environmental Resources Management:
www.co.niiami-dade.fl.us/derm/
globalwarming.
WQH&QE COUNTY
Growth Management Division
3101 Overseas Hvvy.
Marathon, FL 33050
MIAfVII-DADE COUNTY
Department of Environmental
Resources Management
33 S.W. 2nd Avenue, Suite 1200
Miami, FL 33130
FLORIDA DEPARTMENT OF
COMMUNITY AFFAIRS
2555 Shumard Oak Boulevard
Tallahassee, FL 32399-2100
U.S. ENVIRONMENTAL .
PROTECTION AGENCY
Office of Air and Radiation (6205J)
120° Pennsylvania Avenue, NW
Washington, DC 20460
Printed on paper that contains at .
least 30 percent post-consumer fiber.
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I ost beaches along the Atlantic and Gulf
I Coasts of the United States are eroding
I a few feet per year. In Florida, beach
erosion has been attributed .partially to the con-
struction and maintenance of inlets, but rising sea
level is the primary reason that most shores
erode. Rising global temperatures and gradually
sinking land contribute to the higher water levels.
Along the Florida shore, the *sea level is rising .
1 inch every 11-14 years. Approximately 328 . .••;
miles of sandy beaches are eroding :enough to '..'•".;-.
threaten existing developments arid: recreation : '
areas. That's about 40 percent of Florida beaches.
In some other coastal'states, homeowners are
removing their oceanftont houses along eroding
shores. The beach survives, but the building is
lost. Along bay-shores in most states, owners
often protect their homes from erosion by
replacing the natural beach with wooden walls
(bulkheads) or piles of rock (revetments). The
property survives, but the beach Is lost. A few
states have implemented "rolling easements,"
which protect private property rights but also
ensure that beaches are not replaced with bulk-
heads and revetments.
In Florida, people want to keep the beach and
their homes, so you may see dump trucks releas-
ing sand and bulldozers spreading it to rebuild'a
beach, or a dredge pumping sand from the sea ~
floor through a pipe to the beach, or homeown-
ers putting up fencing and planting grasses to
hold the dunes. Without these activities, com-
munities will lose beaches, shorefront homes,
condominiums, hotels, and other buildings.
The Coast
f arbon dioxide and other gases in the
atmosphere transmit sunlight to the Earth's
^surface but retain heat that would otherwise
escape into space. This mechanism is called the
"greenhouse effect" because it is somewhat like
the way that the glass in a greenhouse traps heat.
The atmosphere's greenhouse effect keeps the Earth
60° Fahrenheit warmer than it would be otherwise.
But human activities, such as burning oil, coal,
and natural gas in everything from power plants
to cars and boats, are increasing the concentration
of greenhouse gases. As a result,, the Earth has
•warmed almost 1° Fahrenheit in the last century.::,
Warmer temperatures increase the intensity of
storms. Higher temperatures 'also raise the sea.
level by.expanding ocean water and melting'.
mountain- glaciers; Rising sea level erpdes'beach-
es, increases flooding, threatens'coastal^habitat,
and eventually would threaten the.water.supply
of South Florida. • "•''. ;-.O - ••
Sea Level Trends 1900 - 2000 . ,
Mayport
St. Petersburg
Cedar Key
• 1940 1960
Year
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Much of the Florida shore is developed. As
the sea rises, the beach is squeezed between
the sea and the first row of buildings.
Aiong ocean shores, this means less room
for vacationers and ioca! residents to sun-,
bathe, play volleyball, or build sandeas-
tles. Likewise, there is less room for sand-
pipers, terns, sea turtles, and other wildlife
that feed and breed in the sandy habitat.
Aiong the coast of Florida, sea level has
risen 7 to 9 inches in the last century. Rising
global temperatures contributed 1 to 4
inches to sea level in the last century, bjat
they could raise the sea another 1 to 3
feet in the next century, in addition to the
rise caused fay other factors. A 1-foot rise
would erode most Florida beaches 100-
200 feet unless measures were taken to
hold back the sea. A 3-foot rise would
require the state to spend $4 to 3 billion
Just to replace the sand that would be lost
to beach erosion.
Since 1886, Florida has been hit by 150 hurricanes
and more than 250 tropical storms. More than
60 percent of Florida's population lives within 10
miles of the coast, in the areas most susceptible
to hurricane damage.
Hurricanes and other tropical storms can temporarily
raise the sea 5 to 10 feet—or more. Higher sea level
brings higher floods, which might block evacuation
routes unless roads are elevated. Narrowing beaches
could enable storm waves to reach oceanfront build-
ings, roads, and boardwalks. Increased rainfall from
global warming would further intensify flooding,
and the higher water levels in the canals would slow
the rate at which low-lying areas drain.
The Federal Emergency Management Agency
estimates that a 1-foot rise in the sea level would
increase flood insurance premiums by 35 to 60
percent. Hotels and landlords generally will pass
these costs on to visitors.
The Everglades already are stressed by water
diversions, invading species of plants and animals,
and natural droughts, floods, and storms. Sea level
rise adds to these pressures, by enabling salt water
to advance inland, which can kill sawgrass in the
Everglades and cypress trees in freshwater swamps.
Florida's beaches, small islands, marshes, mangroves,
and cypress swamps provide habitat for species
such as key deer, manatees, storks, snail kites, sea
turtles, panthers, alligators, and crocodiles. Sea
level rise could threaten many of these ecosystems.
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M The state dedicates $30 million per year for
beach replenishment.
B The state's Coastal Construction Control Line
program protects beaches and dunes from
construction that could weaken, damage, or
destroy the .integrity of beach and dune systems.
;
H Florida's Long-Term Redevelopment Program
helps communities plan for and complete
projects that will reduce their vulnerability
to catastrophic storms.
• The State of Florida, Miami-Dade County, and
the South Florida Water Management District are
, working with the U.S. Army Corps of Engineers
and other federal agencies to reduce saltwater
intrusion into the Everglades.
B Broward, Miami-Dade, Hillsborough, Orange,
and Sarasota counties participate in the Cities
for Climate Protection Campaign to reduce
their emissions of greenhouse gases.
II More than 150 Florida companies participate
in voluntary programs to reduce greenhouse
gas emissions. For example, five Florida electric
utilities have set targets for carbon dioxide
emissions reductions.
H Florida's Local Mitigation Strategy program
supports efforts by communities to develop
their own hazard-reduction strategies.
Background photo: Miami Beach, Courtesy of
Greater Miami Convention and Visitors Bureau
Use mass transit, carpool with friends, or ride a
bike whenever possible.
Haul in sand or plant vegetation to hold back
the sea rather than building a seawall, if you
own a shorefront home threatened by erosion.
Enjoy the sea breeze, listen to the waves, and
turn off the air conditioner.
Consider replacing your car with one that gets
more miles per gallon. •
Avoid walking on sand dunes and destroying
their ability to protect the shorelines from
storms and erosion.
Look for the ENERGY STAR® label identifying
energy-efficient models, when it's time to
replace an appliance.
Talk to your insurance agent about federal flood
insurance, if your home is at risk. Homeowners
insurance does not cover flood damages.
Buy products that feature reusable, recyclable,
or reduced packaging to save the energy
required to manufacture new containers.
If you choose to live in a high-risk area, build
your home behind a dune and make sure that
the structure is designed to withstand a severe
hurricane.
Big Pine Key, Provided by Monroe County,To.urht
lit Couna^
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lorida has 4,500 square miles pf land within 4.5 feet of sea
level. Although that land is only 8 percent of the state, it is
concentrated in South Floridaj. Mangrove swamps comprise
i
most of the land within 1-2 feet above: sea level, while areas between
2 and 4.5 feet are mostly freshwater wetlands. The high water mark
and the inland extent of both mangroves and brackish water tend to
be about 1-2 feet above sea level. Therefore, the red represents the area
that could be subjected to tidal flooding or saltwater intrusion, and
where mangroves might be found if the sea rises 2.5 feet.
The Biscayne Aquifer provides almost all of the freshwater for the
Keys, Miami, and the lower East Coast of Florida. Although a small
part of the aquifer is beneath the salty mangrove area, most of it is
recharged by the freshwater Everglades. If sea level rises a few feet,
however, then saltwater could invade part of the Everglades, threatening
both that ecosystem and the aquifer that lies beneath it. Ongoing
efforts by the South Florida Water Management District and other
water management districts to prevent saltwater intrusion will almost
certainly have to be strengthened as the sea rises.
Fortunately, very little development is less than 4.5 feet above sea
level. The 4,500 square miles between 4.5 and 11 feet, however, are
extensively developed, especially in the Keys, the bay sides of barrier
islands, and the areas around Biscayne Bay and Charlotte Harbor.
Those' areas will not be submerged by the tides for a long time, but
they are likely to experience increased flooding from both the higher
sea and increased storm intensity. Recognizing these risks, the
Southwest Florida Regional Planning Council currently is working
with the counties around Charlotte Harbor to determine the most
appropriate response.
v V
5 l ,
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Tampa
rsburg
i Jacksonville',
1 I * t f
Daytona Beach
below 4.5 feet
4.5 -11 feet
above 11 feet
Biscayne Aquifer
Mangroves
50 miles
W
Source: Titus, J.G. and C. Richman. 2001. Maps of Lands
Vulnerable to Sea Level Rise: Modeled Elevations along
the U.S. Atlantic and Gulf Coasts. Climate Research.
18:205-228. This map is based on modeled elevations,
and it is a fair and unbiased graphical representation of
the total amount of land within 4.5 and 11 feet of sea level.
However, up to 10 percent of the elevations shown in this
map may differ from the true elevations by more than 5 feet.
Those interested in precise elevations of specific locations
should 'consult a topographic map or obtain a survey.
mtusyll e|33ilt:
, Palm Beach
Lake ^;
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