SEA LEVEL RISE
By: Virginia Beam, Lyn Buchanan, Justin
Heter, Chandler Madray and Ronnie Smith
OUTLINE
• Introduction – Lyn
• Global Impacts – Justin
• Local Impacts – Ronnie
• Economic Impacts – Virginia
• What Needs To Be Done – Chandler
• Conclusion - Lyn
GLOBAL WARMING
 Many scientists believe
that sea level will rise
as a result of global
warming caused by
human activities.
 However, the complex
nature of earth’s climate
patterns makes it hard
to predict the future.
THE EARTH’S CLIMATE IS CHANGING
• Earth’s climate has been
stable since the last ice age
– less than 1 C in the past
10,000 years
• Earth’s surface is warmer
than any century during the
last thousand years
• Three warmest years during
last one hundred years have
all occurred in the 1990’s
• Twelve warmest years during
last one hundred years have
occurred since 1983
FINDINGS ON THE IPCC 2001
ASSESSMENT – 20th century

Global mean surface temperature has increased by about
0.6 C°

Sea level has risen between 0.1 and 0.2 meters

The increase in temperature is likely to have been the largest of any
century during the past 1,000 years

Concentration of atmospheric greenhouse gases have continued to
rise as a result of human activities
PROJECTIONS FROM THE IPCC
ASSESSMENT – 2001
• The projected rate of warming is much
larger than observed changes during
the 20th century and is likely to be
without precedent during at least the
last 10,000 years.
• The global mean sea level is projected
to rise by 0.09 to 0.88 meters between
1990 and 2100.
HUMAN INDUCED WARMING EFFECT?
• Fact: CO2 in
atmosphere traps heat
• For the last 10,000 yrs.
there has been a
constant level of CO2
(about 280 ppm)
• 100 years ago CO2
began increasing – now
360 ppm (last seen
400,000 yrs. ago)
OR…NATURAL PHENOMENON?
• The planet’s temperature is constantly rising and
falling.
• Current interglacial period – the Holocene Period –
there have been seven major warming and cooling
trends.
• Temperature variation averaged as much as 1.8 F.
(.3 F. more than the temperature increase of the last
150 years)
• Also, of the 6 temperature variations, 3 produced
temperatures warmer than the present average
temperature of 59 F.
-
• What ever the
cause, one of the
major consequences
of global warming
will be sea level rise.
• Low-lying coastal
areas throughout
the world will be
effected.
Global Impacts of Sealevel Rise
By: Justin Heter
Major case studies are being conducted in areas were
flooding is common due to low-lying, river deltas, where
sea-level rise is a great risk. Deaths are related to severe
flooding in these areas.
Mississippi Delta
East coast of South America
Tees Estuary and the Wash in England
North Norfolk Coast
The Netherlands
Egypt
Bangladesh
Hong Kong
Limestone reefs in the Red Sea, near Sharm Abhur, in the west coast
of Saudi Arabia, as well as other coral reefs around the world, are
being affected by sea level rise.
•
•
Salt water intrusion on raised reefs
is eroding reefs
Higher sea level means less sunlight
to the reefs can receive
Barrier islands are being eroded due to rising sea
level.
Greenland and Antarctica are experiencing
isostatic rebound.
Estuaries, very dynamic and sensitive areas where
fresh water mixes with saltwater,
suffer as salinity levels increase with rising
waters.
Coastal aquifers are experiencing saltwater
intrusion with rising waters.
New England, the West Coast, and other areas
around the world are dealing with massive cliff
erosion problems associated with wave damage.
Many coastal areas are building infrastructures to protect the coast.
These structures are expensive, damage the marine habitats, create
problems for sand migration, and create rip tides. Hong Kong:
Many island states are at serious risk of being engulfed by the rising sea. The
Caribbean Islands, the Pacific Ocean Isles-Federated States of Micronesia, Tonga,
South Pacific Island Nations, Yap Islands, Indian Ocean-Mauritius, Sri Lanka are all
under study for this environmental problem.
Local Effects
Eastern North Carolina
by: Ronnie Smith
Map of Vulnerable Lands
• Over past century,
sea level has risen
approximately 2mm
a year in the Cape
Fear area.
• By 2100, sea level is
likely to rise 12
inches in NC
Wetlands
•
•
•
•
Support diverse food webs
Filter out pollutants
Provide storm and flood protection
Serve as groundwater recharge areas
Wetlands - Tidal Marsh
• Tidal marshes are
located within the tide
ranges and are
dependant upon
periodic flooding.
• These and other
wetlands in the
transition zone naturally
adapt to rises in sea
level.
• When marsh becomes
inundated, high marsh
becomes low marsh,
and upland areas
become high marsh.
Natural Impacts
• If the land has a constant gradual slope
throughout the lowlands and the uplands,
then there would be no loss of wetlands
• In most areas, the slope above the marsh is
steeper than the than the marsh, so a loss in
wetlands would occur.
• Usually the sedimentation of wet areas allow
the marsh to keep up with the rising sea, but
a 1 cm/year rise in sea level would not allow
the wetlands to build upward.
Human Impacts
• Development and
bulkheads can
prevent the wetland
from retreating.
• Dams reduce the
amount of sediment
coming from inland.
Setbacks
• 75 feet landward from estuarine
shorelines
• 575 feet landward of estuarine
shorelines adjacent to outstanding
water resources (OWR)
• 30 feet from the high water level for
public trust waters which are further
inland in freshwater.
Barrier Islands
• As sea level rises,
barrier islands tend to
migrate landward by
washing over.
• The overwash process
naturally allows the
island to keep pace with
rises in sea level.
• The sediment in the ebb
tidal deltas and behind
the islands would allow
the marsh to increase.
Barrier Islands
• If islands were to be
breached, waves
would wipe out the
marshes.
• Outer Banks, Topsail
and others
Development
• On developed islands,
beach renourishment
protection will almost
guarantee that an island
will not break apart,
therefore protecting the
wetlands from
inundation.
• However, development
also interferes with the
overwash process that
supplies the wetlands
with sediment.
Beach Renourishment
• Sea level is likely to rise 12 inches by
2100.
• With a 20 inch increase in sea level rise,
the cost of renourishing NC’s coasts
would cost 660 million to 3.6 billion.
• It may not be cost effective in some
areas of the state.
Flooding
• Elevated water
would make storm
surges higher
• A decrease in
wetlands would
increase floodwater
inland
Local Areas Effected
• The cost of beach
renourishment on
the barrier islands in
Outer Banks and
New Hanover Co.
will increase.
• The land below 1.5
meters can
experience a loss in
freshwater wetlands
from salt water
intrusion.
Economic Impacts
in North Carolina
• The cost of coastal protection would
increase.
• Important fish populations could
decrease due to a loss in wetlands
• Tourism revenue could be decreased if
islands were to be lost.
What needs to be done to reduce the rate
of Sea Level Rise by chandler
• Reduce the dependency of fossil fuels
• Curb deforestation
• Curb building in zones that will be
affected by Sea Level rise
Reduce fossil fuel use
• Increase fuel economy for cars and
trucks
• Alternate forms of transporation,ie mass
transportation, bike paths and side
walks
• Alternate energy sources other then
coal and crude oil
Curb deforestation
• Natures way of using CO2
• Plant more trees
Plan building
• Land use planning in zones that are
deemed hazardous
CONCLUSION
• Maryland – Sea Level Rise Response
Strategy
• Policy and implementation framework
for reducing the state’s over-all
vulnerability to sea level rise
–
–
–
–
Shore erosion taskforce
Shore erosion control program
Local hazard mitigation plans
State wetlands conservation plan
Australia – Planning for Sea Level Rise
• Planning for SLR has been incorporated into state
strategic planning documents.
• Queensland, a new state Coastal Management Plan
prescribes the inclusion of climate change issues,
including SLR into local planning.
• Guidelines for SLR planning are incorporated into the
plans of all local councils in New South Wales.
• Funding for plans is a problem.
AS SEA LEVEL RISES
• Many who inhabit the
world’s populated coastal
regions will suffer economic
and social upheaval.
• Developed nations will
spend billions to prevent
flooding and protect water
supplies, but the poorer
nations cannot afford these
protections.
• Coastal ecology will be
compromised and coastal
livelihoods threatened.