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.

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• 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 Sea-level 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 Impactsin 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.

• 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.

AS SEA LEVEL RISES