**1998 Year of the Ocean**

**IMPACTS OF GLOBAL CLIMATE CHANGE---**

**WITH EMPHASIS ON U.S. COASTAL AREAS**

**Contents**

1\. EXECUTIVE SUMMARY G-2

2\. INTRODUCTION G-6

3\. SEASONAL TO INTERANNUAL CLIMATE IMPACTS G-8

4\. DECADAL TO CENTENIAL CLIMATE IMPACTS G-17

5\. GLOBAL CLIMATE CHANGE IMPACTS ON U.S. COASTAL AREAS G-24

6\. REFERENCES G-43

7.  DOMESTIC LEGAL REGIME G-47

8.  LIST OF ACRONYMS G-52

This Year of the Ocean document was prepared as a background discussion
paper and does not necessarily reflect the policies of the U.S.
Government or the U.S. Government agencies that participated in its
preparation.

**EXECUTIVE SUMMARY**

The Earth's weather and climate are the result of the redistribution of
heat. The major source of heat to the surface of the Earth is the sun,
principally through incoming visible radiation most of which is absorbed
by the Earth's surface. This radiation is redistributed by the ocean and
the atmosphere with the excess radiated back into space as longer
wavelength, infrared radiation. Clouds and other gases, primarily water
vapor and carbon dioxide, absorb the infrared radiation emitted by the
Earth's surface and remit their own heat at much lower temperatures.
This "traps" the Earth's radiation and makes the Earth much warmer than
it would be otherwise.

Most of the incoming solar radiation is received in tropical regions
while very little is received in polar regions especially during winter
months. Over time, energy absorbed near the equator spreads to the
colder regions of the globe, carried by winds in the atmosphere and by
currents in the ocean. Compared to the atmosphere, the ocean is much
denser and has a much greater ability to store heat. The ocean also
moves much more slowly than the atmosphere. Thus, the ocean and the
atmosphere interact on different time scales. The ocean moderates
seasonal and longer variations by storing and transporting, via ocean
currents, large amounts of heat around the globe, eventually resulting
in changing weather patterns.

The ocean also plays an important role in climate change. Long-term
impacts of climate change in coastal areas, such as sea level rise or
storm surges, could result in the increased erosion of shores and
associated habitat, increased salinity of estuaries and freshwater
aquifers, altered tidal ranges in rivers and bays, changes in sediment
and nutrient transport, and increased coastal flooding. Such changes
have considerable implications for U.S. coastal areas where the majority
of the country\'s population and significant economic activity is
concentrated.

The purpose of this document is to consider how the ocean influences
weather and climate and how climatic changes could impact valuable
coastal areas. It also addresses the barriers to progress and the
opportunities presented by the 1998 Year of the Ocean to better
understand and predict weather and climate variability and to address
the coastal impacts of global climate change. This topic spans such a
broad array of considerations that it will be split into three parts:
seasonal to interannual climate impacts, decadal to centennial climate
impacts, and coastal global climate change impacts. Options for
consideration to further advance efforts in each topical area are
included.

**Seasonal to Interannual Climate Impacts**

The global atmosphere and world ocean are an interactive system. The
most important air-sea interaction signal comes from the El
Niño/Southern Oscillation (ENSO) which originates in the tropical
Pacific. In a warm episode (El Niño), the pool of warm water that is
normally found in the western Pacific expands eastward, carrying with it
portions of the precipitation normally found in the far western Pacific.
This shift in the distribution of tropical convection leads to shifts in
jet stream tracks, resulting in climatic anomalies around the world. The
ENSO cycle is rooted in the instability of the coupled atmosphere-ocean
system and occurs over an irregular, quasi-periodic cycle which varies
between three and seven years.

Seasonal to interannual forecasts of the climate variability from ENSO
can now predict climate changes for up to a year. The improved skill and
lead time of these forecasts can result in savings of hundreds of
millions of dollars a year both in the U.S. economy and abroad. Advanced
knowledge of ENSO allows farmers to make decisions to maximize
agricultural yields. ENSO forecasts will also improve fisheries
management because ENSO episodes strongly influence marine catches from
Chile to Alaska. In addition, the benefits of improved predictions to
the water resources and energy sectors of the economy are potentially as
large as those for agriculture and fishing.

To produce useful seasonal to interannual climate forecasts, it is
necessary to both implement an operational climate forecasting system
and to continue to invest in process and modeling research that leads to
improved predictability. In addition, enhanced global observation and
data processing systems will continue to be required to support the
research and to initialize and validate model predictions.

The National Oceanic and Atmospheric Administration (NOAA) currently
provides operational seasonal forecasts based on a combination of
dynamical model and statistical predictions for up to one year in
advance for the United States. Although NOAA actively coordinates its
efforts with other federal agencies, the global nature of the climate
signal requires involvement with universities and international
agencies. These partnerships are necessary so that societies from around
the world can benefit from the enhanced predictability and learn to use
the information for broad-based environmental and economic gain.

**Decadal to Centennial Climate Impacts**

The ocean has a huge capacity to transport and store heat and carbon
dioxide (CO~2~), and exchange huge quantities of water and CO~2~ with
the atmosphere at the sea surface. Ocean transports play a large role in
the present climate and its variability. Coupled ocean-atmospheric
models used to predict global temperature changes have shown that the
ocean has the potential to delay the impact of greenhouse gas emissions
and thus affect changes in atmospheric conditions. Models complemented
by observations provide the means to distinguish between natural
variability on decadal to centennial time-scales and anthropogenic
(human influenced) climate change. For example, a recent modeling study,
which looked at a long term record of observed and simulated atmospheric
temperature, suggests that the recent increases could be related to
CO~2~ changes.

Observations describe variations in the climate system while models
provide the mechanism to understand why such variations occur, and to
predict future evolution of the climate system. To improve our
understanding of the climate system, an integrated research program has
been established to improve models to better represent climate processes
and to collect long-term instrumental and proxy observations in the
ocean. The benefits to society of this approach are: (1) improved
detection of climate change signals in the ocean; (2) improved models of
natural and anthropogenic climate variability; (3) quantification of the
predictability of long-time scale climate variability; and (4) reduced
uncertainties in CO~2~ warming scenarios.

**Global Climate Change Impacts on U.S. Coastal Areas**

The United States' coastline stretches for approximately 158,000
kilometers (93,600 miles), bounding some of the most valuable and
heavily used areas in the nation that could be affected by climate
change. Within these coastal areas lie natural and human resources of
tremendous value. These include about 38,900 square kilometers (15,000
square miles) of coastal wetlands, which provide crucial wildlife
habitat and filter toxins from rivers, and 6,500 square kilometers
(2,500 square miles) of developed barrier islands, which support
recreational communities. U.S. coastal areas also support a variety of
important economic activities, including fisheries and aquaculture,
tourism, recreation, industry, and transportation.

U.S. coastal areas are experiencing greatly increased pressures as a
result of rapid population growth and accompanying development. Nutrient
and bacteria pollution from urban and agricultural runoff, changes in
hydrology and salinity to naturally balanced systems, shore erosion, and
over-development all currently stress our coasts. The effects of climate
change would only add to these stresses.

While global climate has fluctuated throughout time, a global warming
scenario could speed this process possibly causing accelerated sea-level
rise (ASLR), alterations of rainfall patterns and storm frequency or
intensity, and increased siltation. The Intergovernmental Panel on
Climate Change (IPCC) has forecasted a rise in global sea level of 5
mm/yr, within the range of uncertainty of 2‑9 mm/yr; or 20, 49, or 86 cm
by 2100. Climate change and a rise in sea level or changes in storms or
storm surges could result in the increased erosion of shores and
associated habitat, increased salinity of estuaries and freshwater
aquifers, altered tidal ranges in rivers and bays, changes in sediment
and nutrient transport, a change in the pattern of chemical and
microbiological contamination in coastal areas, and increased coastal
flooding.

Some coastal ecosystems are particularly at risk, including saltwater
marshes, coastal wetlands, coral reefs, coral atolls, and river deltas.
Other critical coastal resources, such as mangroves and sea-grass beds,
submerged systems including submerged aquatic vegetation and mudflats,
are at risk from climate change impacts, and exacerbated by
anthropogenic factors. Changes in these ecosystems could have major
negative effects on tourism, freshwater supplies, fisheries, and
biodiversity that could make coastal impacts an important economic
concern. Coastal structures, including homes would also be more
vulnerable to increased sea-levels. FEMA has estimated that the number
of homes in the coastal floodplain would more than double under the
highest of sea-level rise scenarios. This growth will be the result of
the increase in the area of the coastal floodplain due to sea-level
rise, as well as the growth of coastal population, which will increase
the number of homes built in the coastal floodplain.

Management strategies in coastal areas can be divided into three
categories: accommodate, protect, and retreat. The successful
implementation of these planned management strategies will depend to a
large measure on the extent of their integration into the implementation
of other national and sectoral management plans, including integrated
coastal management plans. However, because of scientific uncertainties,
the long-term nature of the problem and large investments required,
state and local governments have hesitated to effectively address the
issues relating to climate change. Consequently, management responses to
climate change impacts have been gradual since the early 1980s, but
pioneering efforts have been important for U.S. policy makers. A major
educational challenge is to convince the public of the urgency for
taking measures now, through integrated coastal management, to deal with
long-term coastal climate change impacts.

**INTRODUCTION**

Developing an understanding of both weather and climate means developing
an understanding of the Earth's heat budget, i.e., how the energy from
incoming solar radiation is redistributed around the globe. The major
source of heat to the surface of the earth is the Sun, principally
through incoming visible radiation. Heat is generated in the Earth's
interior, for example through the decay of radioisotopes; however, this
contribution to the heat balance of the surface of the Earth, where most
life exists, is small compared to the solar flux. Clouds, ice caps and
snow make the Earth a relatively bright planet such that about 30
percent of the incoming solar radiation received at the top of the
atmosphere is reflected back into space. A very small fraction is
absorbed directly by gases and aerosols as it passes through the
atmosphere. Most of it is absorbed by the Earth's surface. This
radiation is redistributed by the ocean and the atmosphere and the
excess is radiated back into the atmosphere and space as longer
wavelength, infrared radiation.

If our atmosphere consisted of just nitrogen and oxygen, the global
average surface temperature of the planet would be about 33°C (60°F )
colder than it is now and the Earth would be a frozen wasteland. This is
not the case because of the presence of clouds and small quantities of
other gases, primarily water vapor and carbon dioxide, that absorb much
of the infrared radiation emitted by the Earth's surface and reemit
their own heat, as radiation, at much lower temperatures. This "traps"
the Earth's radiation and is the mechanism for planetary warming, "the
greenhouse effect" (Figure 1).

Aside from the gases in the atmosphere, clouds also play a major role in
climate. By reflecting solar radiation away from Earth, some clouds act
to cool the planet while other types of clouds warm the Earth by
trapping heat near the surface. For years, it was not known whether
clouds warmed or cooled the planet. Recent satellite measurements have
proven that clouds exert an overall powerful cooling effect on the
Earth. In some areas, however, such as the tropics, heavy clouds may
markedly warm the regional climate.

Clouds and greenhouse gases fit into a global radiation budget, a budget
that must balance itself. Most of the incoming solar radiation is
received in tropical regions while very little is received in polar
regions especially during winter months. Over time, energy absorbed near
the equator spreads to the colder regions of the globe, carried by winds
in the atmosphere and by currents in the ocean. The small amount of
energy retained in the atmosphere is redistributed, basically, by winds.
The time it takes for the atmosphere to mix around the globe is
approximately one month. In its simplest form, an understanding of
weather is an attempt to understand winds. Compared to the atmosphere,
the ocean is much denser and has a much greater ability to store heat.
The ocean also moves much more slowly than the atmosphere and
distributes heat at a much slower rate. Because the ocean covers nearly
two-thirds of the surface of the earth, the combined effect of the
ocean's heat capacity and its coverage of the Earth's surface means that
much of the heat received from the sun that is retained within the
biosphere is stored in the ocean.

![](media/image1.emf){width="6.260416666666667in" height="5.53125in"}

The ocean and the atmosphere interact on different time scales. As the
time scales change from weather time scales (minutes to weeks) to the
longer time scales of climate, the interaction between the ocean and the
atmosphere changes as more of the ocean becomes involved. Thus, on
weather time scales generally only sea surface temperatures (SST) are
involved. At time scales of seasons to years, the upper layers of the
ocean (a few hundred meters) have an influence, while at time scales of
decades and longer the entire ocean plays a role. The transport of heat
by surface ocean currents, for example, modifies mid-latitude
temperatures across ocean basins so that land areas on the eastern
boundaries of ocean basins are generally warmer than areas at the same
latitude on the western boundary.

The purpose of this document is to consider how the ocean influences
weather and climate and to address the barriers to progress and the
opportunities presented by the 1998 Year of the Ocean to better
understand and predict weather and climate variability. This topic
includes seasonal to interannual forecasts, as well as prediction of
long term climate change such as temperature and sea level. Because this
paper spans such a broad array of considerations, it will be split into
three parts: seasonal to interannual climate impacts, decadal to
centennial climate impacts, and coastal global climate change impacts.
The ocean's influence on weather has its largest economic and social
impact on coastal areas and will be considered in the coastal section.

**SEASONAL TO INTERANNUAL CLIMATE IMPACTS**

**Introductory Considerations**

The ocean's influence on climate can be split into normal seasonal cycle
influences and departures from normal. Commerce, agriculture, and
industry have all evolved to operate best with normal seasonal changes.
However, changes from the seasonal normal, for example floods and
droughts, can lead to economic disruptions and human suffering. Thus,
predictions of climate differences from the expected or normal pattern
on seasonal and longer time scales can be of great importance to
society.

The best understood, strongest, and somewhat consistent interannual
air-sea climate signal comes from the El Niño/Southern Oscillation
(ENSO) which originates in the tropical Pacific. Under normal
conditions, the prevailing trade winds blow from east to west and thus
contribute to higher ocean temperatures in the west. Associated with
these temperatures are a higher sea level and deeper thermocline in the
west than the east. (The thermocline is the boundary between warmer
surface waters and the colder water below.) In addition, convective
rainfall is located in the far western Pacific Ocean over the warmer sea
surface temperatures (see the upper panel of Figure 2). In a warm
episode (El Niño), the trade winds weaken and warmer water expands
eastward, carrying with it portions of the precipitation. This change
includes a reduction of the sea level and thermocline depth in the west
and an increase in the east (see the lower panel of Figure 2). There are
also cold episodes which are generally the inverses of the warm episode
shown in the figure. The term ENSO will be used to refer to both a warm
and a cold episode; El Niño will be used to specify a warm episode, and
La Niña will be used to specify a cold episode.

The shift in the distribution of winds, surface temperatures, and
tropical convection leads to changes in the atmospheric circulation with
the possibility of regional droughts, floods, and temperature changes in
areas well beyond the tropical Pacific. The typical dependence for El
Niño is shown in Figure 3 for Northern Hemisphere winter and summer. In
northern middle latitudes, the strongest relationship occurs in the
Northern Hemisphere winter when the atmospheric circulation is
strongest. The figure shows that El Niño tends to cause warmer than
normal winter temperatures in the U.S. Pacific northwest and higher than
normal winter precipitation along the U.S. Gulf Coast. La Niña generally
impacts the same areas as El Niño but with opposite effects. The ENSO
cycle is rooted in the instability of the coupled atmosphere-ocean
system. The instability produces repetition of an irregular,
quasi-periodic cycle which varies between three and seven years.

The ENSO research effort includes studies on the evolution of sea
surface temperatures (SST) as part of the oceanic response to
atmospheric forcing and meteorological studies on regional and
large-scale air-sea interactions. Thus, monitoring and prediction of sea
surface temperatures is an important part of monitoring and predicting
ENSO. SST anomalies for 1950 to present are shown for a region with
strong ENSO variability (10°N-10°S, 150°W-90°W) in Figure 4. The
anomalous SSTs shown here are computed as the difference between
measured monthly SSTs and the normal expected monthly SSTs for the
period 1950-79. The figure shows positive and negative SST anomalies.
Although the distinction between normal, El Niño, and La Niña is not
rigorously defined, SSTs which persist for at least six months above
roughly 0.75°C can be considered to indicate El Niño, while those that
persist below -0.75°C can be considered to indicate La Niña. The figure
also shows an overall warming of the tropical ocean by 0.5°C in the
decades of the 1980s and 90s with stronger El Niño episodes occurring in
the latter part of the record. The strongest complete El Niño occurred
in 1982-83. However, if current predictions are validated, the present
El Niño episode may become even larger and persist into 1998, which has
been designated the Year of the Ocean.

ENSO (El Niño and La Niña) episodes cause changes in the normal global
atmospheric circulation. The changes lead to changes in precipitation
and temperature which strongly depend on season and location as shown in
Figure 3. Areas that are strongly impacted during Northern Hemisphere
fall and winter are the south of Africa, Australia, South America, and
the U.S. The occurrence of El Niño or La Niña does not guarantee a
specific precipitation or temperature response, but only increases the
likelihood that a deviation from normal will occur.

Although crop yields depend on many factors, rainfall during part of the
growth cycle is often critical. Despite the uncertainties, links between
both El Niño and La Niña and crop yields have been established in a
number of regions. As an example, winter crop yields in Texas, Oklahoma,
Kansas, and Colorado show that the presence of El Niño, with its
likelihood of increased rainfall, can increase yields by 15 percent,
while La Niña, with its likelihood of decreased rainfall, can decrease
yields by 15 percent.

![](media/image2.emf){width="6.260416666666667in" height="8.46875in"}

![](media/image3.emf){width="6.25in" height="8.489583333333334in"}

During normal years, winds along the equator and along the coast of Peru
and the west coast of North America, push surface waters offshore
bringing cold, nutrient rich waters from below to the surface a process
known as upwelling. These cold, nutrient rich waters stimulate plant
growth resulting in well-established plankton populations and the
species which feed on them that include fish, birds, and marine mammals.
During El Niño periods, the winds change, upwelling decreases, and the
normal plankton population decreases. The animals which feed on the
plankton either move elsewhere or die. For example, the 1972-73 El Niño
coupled with overfishing caused a collapse of the anchovy fishery off
Peru. In addition, in the Pacific northwest, El Niño leads to changes in
the salmon fisheries. This is linked to more northward migration of
mackerel which prey on juvenile salmon.

ENSO episodes can now be predicted to a level of skill and with enough
lead time that hundreds of millions of dollars a year can be saved both
in the U.S. economy and abroad. A recent interdisciplinary study
estimated the value of improved ENSO forecasts to U.S. agriculture to be
between \$240 and \$325 million per year. A draft study estimates the
benefits of a perfect forecast in crop storage to be \$240 million
annually for corn alone. Advanced knowledge of ENSO will allow farmers
to make decisions to maximize agriculture yields. ENSO forecasts have
the potential to improve fisheries management because ENSO episodes
strongly influence marine catches from Chile to Alaska. In addition,
ENSO-induced changes in precipitation can lead to increases in the
threat of mosquito-borne diseases such as malaria. The U.S. Centers for
Disease Control and Prevention and the World Health Organization are
building programs to utilize climate forecasts for enhanced health
surveillance and early-warning systems.

Benefits to the water resources and energy sectors are potentially
large. The availability of fresh water for irrigation and household use
is fundamental to economic well being and varies dramatically during
ENSO episodes. ENSO episodes have been linked to regional droughts and
an increase in the number of forest fires due to decreased
precipitation. Decisions on the purchase and distribution of fuels could
be made more cost effective, or estimates of fuel demand based on
anticipated climate trends could contribute to more efficient decisions
regarding options for purchasing different energy supplies.

To produce useful seasonal to interannual climate forecasts, it is
necessary to implement an operational climate forecasting system. It is
also necessary to continue to invest in process and modeling research
that leads to improved predictability of temperature and precipitation.
In addition, enhanced global observing and data processing systems will
continue to be required to support the research and to initialize and
validate model predictions.

**Status of the Relevant Science and Technical Base**

Because of limited observational capabilities before the 1980s, it was
not even possible to know if an El Niño episode was underway until
several months after the episode began. Progress in climate prediction
in the 1980s and early 1990s has been stimulated by the development of
models used for ENSO prediction, by empirical and theoretical studies to
better understand the global impact of ENSO studies, and by the
establishment of an ocean observing system (primarily in the Pacific)
for initializing and verifying models for ENSO prediction.

The in situ observing system in the Pacific Ocean improved dramatically
during the 1985-94 Tropical Ocean Global Atmosphere (TOGA) period (see
Figure 5). The most important component of this system is the National
Oceanic and Atmospheric Administration (NOAA) Pacific Marine
Environmental Laboratory (PMEL) Tropical Atmosphere Ocean (TAO) moored
buoy array which provides basin-wide real-time measurements of surface
and subsurface ocean temperature and surface atmospheric winds. These
data are augmented by other in situ observations of these same
quantities plus additional variables such as upper level atmospheric
winds, sea level, and sea level pressure. In addition, remotely sensed
observations systems from geostationary and polar environmental
satellites give true global coverage of many atmospheric and oceanic
variables. The present observing system is a fully multinational effort
which is supported by more than two dozen countries.

Models used in ENSO prediction range from purely statistical models to
fully coupled dynamic ocean-atmosphere models. Most of the experience in
dynamical forecasting is based on an intermediate class of models which
simulate only climate differences from normal in order to avoid problems
with model climate drift. Some of the simpler models do not make full
utilization of all the available data. The more complex coupled general
circulation models make better use of the available data and are
producing superior ENSO forecasts.

Many developing countries are strongly affected by ENSO episodes because
their economies are dependent upon agricultural sectors as a major
source of food supply, employment, and foreign exports. In these
countries, droughts predicted up to several months in advance, coupled
with the response of local farmers, have already contributed to
maintenance of food supplies. For example in the Brazilian state of
Ceara, agricultural officials used the predictions of the 1991-92 EL
Niño to change the timing and types of crops planted. That year Ceara
had harvests at near normal levels compared to the massive crop failures
experienced during the 1986-87 El Niño.

For procedures such as these to work, it is desirable to have full and
open access to data and analysis products among all participating
nations, organizations, and institutions. In some cases, national
security interests restrict the exchange of information. Moreover, a
weakness of ENSO investigations is the limited cooperation among
interdisciplinary groups. For example, coupled ocean-atmosphere models
include analyses of ocean temperature, salinity, and currents. These
data fields would be useful to biologists who wish to understand impacts
of ENSO on the distribution of marine species.

The Tropical Ocean Global Atmosphere Program concentrated on ENSO with
great success. However, other interannual signals in other tropical
oceans and at high latitudes were ignored. For example, changes in the
tropical Pacific account for only part of the variability observed over
North America in temperature and precipitation. There are also emerging
efforts to understand the variability and predictability of the American
and the Asian-Australian monsoon

![](media/image4.emf){width="6.260416666666667in"
height="8.666666666666666in"}

systems, the predictive air-sea interactive signal in the Atlantic known
as the North Atlantic Oscillation, and decadal and longer climate
variability.

**Techniques and Arrangements for Managing Seasonal to Interannual
Climate Impacts**

NOAA, through the Climate Prediction Center of the National Centers for
Environmental Prediction, currently provides operational seasonal
forecasts based on a combination of dynamical model and statistical
predictions for the U.S. for up to one year. NOAA actively coordinates
its efforts with other federal agencies, principally NSF, NASA, and DOE.
In addition to the federal agencies, the global nature of the climate
signal requires involvement with universities and international
agencies. These partnerships remain essential to develop the practical
benefits of ENSO forecasts, and to move toward the understanding and
prediction of other forms of climate variability.

Research programs are being developed to extend the predictability of
ENSO and the accompanying oceanic and meteorological effects. These
programs include the Global Ocean Atmosphere Land System Program which
extends the original research effort begun by the Tropical Ocean Global
Atmosphere Program, and the Global Energy and Water Cycle Experiment
Program which improves the parameterization of water and energy fluxes
in coupled air-ocean-land models.

A multinational Seasonal-to-Interannual Climate Prediction Program
(SCPP) was designed to provide reliable forecasts and analyses of
climate variations on seasonal to interannual time scales, and to
develop the infrastructure by which this information can be used. The
goal of SCPP is to take the next step toward reliable forecasts and
analyses of climate variations on seasonal and interannual time scales,
and to develop the infrastructure by which this can be used for social
and economic benefit by all countries of the world. The program would
initially focus on forecasting ENSO and the related climate impacts
(atmospheric circulation, precipitation, and surface temperature), and
will expand based on the results of continuing research.

A key component of the SCPP plan is the development of an end-to-end
forecasting system to develop, improve, and transfer climate modeling
technology from research centers to other centers which routinely
produce and disseminate climate forecasts to affected local communities
and local decision makers. This includes the establishment of an
International Research Institute for Climate Prediction. This institute
has the responsibility for generating and distributing experimental
forecasts multinationally. The forecast information will be tailored to
the specific area and take into account climate conditions, forecast
needs, and interests as indicated by local decision makers and managers.

**Issues Pertaining to Education and Human Resources**

A major focus of climate research is the development of an informed and
responsible citizenry who are knowledgeable about climate variability.
This includes assessing the impacts of climate variability on human
activity and economic potential, and improving public education so
climate forecasts are understood and used.

Societies from around the world could benefit by participating in a
shared multinational mechanism to maintain and enhance predictability,
and learn how to incorporate the information into decision making for
broad based environmental and economic gain. Note that on a basic level,
activities such as agriculture, fishing, water management, and fuel
distribution must take into account the climatological mean annual cycle
crops are planted in anticipation of the optimal growing season,
fishing vessels in Peru and Oregon are readied for the seasons when
wind-driven upwelling provides nutrients for the food chain; reservoir
levels are lowered in anticipation of spring flooding; fuel oil is
distributed in anticipation of wintertime heating needs.

**Options for Consideration**

The best understood and strongest interannual air-sea climate signal
comes from ENSO which originates in the tropical Pacific and leads to
changes in the atmospheric circulation well beyond the tropical Pacific.
ENSO episodes can now be predicted to a level of skill and with enough
lead time that hundreds of millions of dollars a year can be saved both
in the U.S. economy and abroad.

NOAA currently provides operational seasonal forecasts based on a
combination of dynamical model and statistical predictions for the U.S.
An International Research Institute has been established to provide
forecasts to other nations. For these efforts to succeed, it is
necessary to continue to invest in process and modeling research and to
enhance the global observing and data processing systems. It is also
necessary to continue to study other interannual signals in the tropics
and in higher latitudes. In addition, institutionalized systems, such as
the International Research Institute, must continue to be supported so
that national and international forecasts, as well as other climate
services, can be continued and expanded as predictability of ENSO and
other interannual signals improves. The development of new forecasting
products that can be used for economic, disaster preparedness, and other
planning purposes would also be very beneficial to the nation.

**DECADAL TO CENTENNIAL CLIMATE IMPACTS**

**Introductory Considerations**

Both the atmosphere and the ocean act together as a giant heat engine
with the ocean also playing the role of a flywheel in the system. It
takes approximately 4 years for the surface currents of the world's
ocean bodies to circulate around the globe. As they do so, they give up
their heat to their surroundings and cool. These relatively warm
currents also tend to have a slightly higher salt content than the
waters they circulate through. This is due to increased evaporation at
low latitudes resulting in a small increase in the concentration of
salt. In certain parts of the globe, these waters can cool sufficiently
such that the colder temperatures combined with this higher salt content
make them denser than the surrounding fresh waters. When this happens,
this cold, dense water sinks and enters into the circulation of the deep
ocean. The deep currents of the ocean eventually surface, primarily in
the North Pacific, where they enter into the surface circulation again.
It takes on the order of 700-1,000 years to complete a single circuit of
the global ocean (see Figure 6, the "Conveyor Belt").

The ocean is not only an immense reservoir of heat and water but also of
carbon dioxide (CO~2~). On geological time scales, marine biological
processes act through the uptake of dissolved CO~2~ (photosynthesis) and
its conversion to inorganic carbonate (which is precipitated as
carbonate rock (limestone)) as the major control on CO~2~ distributions
in the Earth's biogeochemical system. On time scales of years, marine
biological systems, as with faster growing terrestrial systems,
equilibrate fairly rapidly with carbon dioxide in the atmosphere. On

longer time scales, transfer of CO~2~ to woody vegetation, soils, and
transfer to the deep ocean removes CO~2~ from the atmospheric system.
The oceanic sink of CO~2~ is considerably larger than the terrestrial
sink. While 10-20 percent of the CO~2~ emitted to the atmosphere by
man's activities has been sequestered by terrestrial processes, some 40
percent of the total CO~2~ emitted by man has been removed from the
atmosphere relatively permanently by oceanic processes.

Increased confidence in understanding climate variability, and potential
impacts by man on climate can only be obtained through improved
representation of ocean climate processes in models, and systematic
collection of long-term instrumental observations of climate system
variables in the ocean. Key uncertainties limit our ability to detect
and project future climate change. In particular, the IPCC 1995 report
lists the following as priority topics:

-   "Representation of climate processes in models, especially feedbacks
    associated with clouds, oceans, sea ice and vegetation, in order to
    improve projections of rates and regional patterns of climate
    change."

-   "Systematic collection of long-term instrumental and proxy
    observations of climate system variables (e.g., solar output,
    atmospheric energy balance components, hydrological cycles, ocean
    characteristics, and ecosystem changes) for the purpose of model
    testing, assessment of temporal and regional variability, and for
    detection and attribution studies."

    These priorities recognize that predicting climate change resulting
    from emissions of greenhouse species and formulating future
    decisions on the possible regulation of these emissions require more
    accurate models, models which have been adequately tested against a
    well-designed network of observations. Observations also serve other
    purposes. Of paramount importance, only observations can detect
    climate change. In addition, observations can provide increased
    understanding of climatically important ocean processes. Finally,
    chemical and physical oceanographic observations provide data needed
    to separate anthropogenic from natural variability.

    ![](media/image5.emf){width="6.260416666666667in"
    height="4.395833333333333in"}

    **Status of the Relevant Science and Technical Base**

    The ocean interior has a huge capacity to transport and sequester
    heat, fresh water, and CO~2~ exchanged with the atmosphere at the
    sea surface. Ocean transports of these play a large role in the
    present climate and its variability. Coupled ocean-atmospheric
    models used to predict global temperature changes have shown that
    the ocean sequestration has the potential to delay the impact of
    greenhouse gas emissions and thus affect changes in atmospheric
    conditions. These latter changes occur both directly by the oceanic
    uptake of 30-60 percent of the anthropogenic CO~2~ currently
    produced, thereby attenuating the atmospheric CO~2~ increase, and
    indirectly by buffering the atmospheric temperature increase due to
    the ocean\'s large thermal mass.

    The present state of models and sparse observations are factors that
    lead to uncertainties in estimates of oceanic transport, uptake and
    sequestration. For example, the current coupled General Circulation
    Models (GCMs) used to simulate climate change fail to produce
    long-term trends in Pacific sea-surface temperature.
    Observationally, three estimates of the transport of heat from south
    to north at 24°N in the Atlantic show a steady rise from 1957
    through 1992. Available data can not resolve if these changes
    represent a natural or an anthropogenic induced trend and/or whether
    they are biased by an unresolved annual signal. Furthermore, the
    uncertainty in ocean dissolve inorganic carbon uptake is 40 percent
    of the total (2.0 billion metric tons of carbon per year). These
    uncertainties must be reduced if confidence in CO~2~ warming
    scenarios is to increase.

    Models complemented by observations provide the means to distinguish
    between natural variability on decadal to centennial time-scales and
    anthropogenic climate change. For example, a recent modeling study
    looked at a long term record of observed and simulated atmospheric
    temperature and found the rates of recent increases in temperature
    in both data sets to be similar. These rates are unprecedented in
    terms of the longer model record suggesting that the recent
    increases could be related to CO~2~ effects.

    An effective approach to improve the representation of climatically
    important ocean processes in models is to test hypotheses on the
    dynamics of naturally occurring, coupled air-sea interactions that
    are found in models and observations. Several candidate hypotheses
    exist. For example, a model forced only by seasonally varying solar
    radiation at the top of the atmosphere includes coupling on decadal
    time scales between two atmospheric patternsa connection between
    the Pacific and North America known as the PNA pattern and a North
    Atlantic pattern known as the North Atlantic Oscillation (NAO) and
    the upper layers of the northern hemisphere middle latitude ocean.
    The NAO is a seesaw pattern in sea-level pressure with nodes over
    the Bermuda High and Icelandic Low. Both atmospheric features have
    been shown to have significant impact on U.S. and European climate
    on many time scales. On decadal time scales this could mean multiple
    years of weather regimes, like drought in the Southwestern United
    States or floods in the South Atlantic states. Observational studies
    of coupled air-sea interactions using recently collected data find
    similarities between the measurements and the coupled model results
    on decadal time scales in both the North Atlantic and Pacific
    basins. However, the comparison studies are still at an early stage
    and validation of this coupled mode requires additional effort.

    Results from another numerical model suggest that on multidecadal
    time scales, the NAO is coupled to the thermohaline circulation of
    the Atlantic. (Thermohaline circulation refers to circulation driven
    by density differences in the water with density being determined by
    temperature and salt content.) Recent observations also show that
    the decadal signal in upper layer temperature and NAO index are both
    superimposed on longer term trends. In addition, analysis of
    historical atmospheric data indicates that a strong decadal signal
    in NAO variability is limited to the past 30 to 40 years.

    Recent model results from the Geophysical Fluid Dynamics Laboratory
    (GFDL) suggest the existence of a mode of climate variability on a
    multidecadal time series involving interactions between the Arctic
    and North Atlantic. This mode is characterized by variations in the
    export of fresh water and sea ice from the Arctic. It has
    substantial impacts on the atmospheric circulation and climate over
    parts of Europe, as well as on the intensity of the thermohaline
    circulation and associated meridional heat transport in the North
    Atlantic. Analyses of observations and various model runs with and
    without CO~2~ increases provide data for: (1) increased
    understanding of the dynamics of the coupled ocean atmosphere
    system; (2) identification of climatically important oceanic
    features to monitor; (3) model validation; (4) predictability
    studies; and (5) separation of natural and anthropogenic climate
    change. For example, observations can be used to benchmark decadal
    and multidecadal variability from model simulations. If the models
    provide realistic results of recent variability, this will offer
    confidence to conduct long simulations and assess the role of CO~2~
    on the air-sea system.

    Recent observations in the Atlantic argue for hypothesis driven
    climate studies in this basin. After decadal increases in the NAO
    index, a significant decrease in this pattern has just occurred
    (with expected changes in European weather). Concurrent with the
    increase in the NAO index, extrema in several properties of the
    thermohaline circulation in the Atlantic have been observed (e.g.,
    convection in the Labrador Sea and lack of convection in the
    Greenland Sea, increased subsurface temperatures in the subtropical
    Atlantic, and recently ventilated waters observed in the deep
    currents along the western boundary of the North Atlantic Ocean).

    Several data-sets have been collected and several observing networks
    are in place that provide a critical foundation for detection of
    climate change. The NOAA/DOE/NSF supported World Ocean Circulation
    Experiment hydrographic program and global carbon survey have
    provided an accurate benchmark for the ocean inventory of CO~2~ and
    other properties. Comparisons of these data with historical records
    are revealing large-scale variability in ocean properties over
    decadal time scales. Synthesis of these data will greatly improve
    estimates of interior ocean fluxes. Analysis of the CO~2~ survey
    data will yield robust estimates of the oceanic uptake of CO~2~ to
    date thereby offering critical constraints on partitioning of
    anthropogenic CO~2~ between the atmosphere, ocean, and terrestrial
    biosphere. Continued direct measurements are needed next to: (1)
    track the rate of change of oceanic CO~2~ and estimate CO~2~ fluxes
    (e.g., GCM\'s suggest that ocean sequestration of CO~2~ decreases in
    response to climate warming); (2) track changes in the storage and
    fluxes of heat and freshwater; and (3) provide data for model
    validation studies.

    Upper layer temperature data are collected, in part, by a global
    Volunteer Observing Ship network. This network provides over 100
    years of surface data including SST and about 30 years of subsurface
    temperature data. Analysis of these data provided the
    characteristics of many of the decadal signals described above.
    There are, however, large areas, particularly in the central and
    eastern northern oceans and all of the southern oceans, where little
    or no data are available. Data sparsity in the northern hemisphere
    precludes validation of several of the theories described above. In
    the southern hemisphere, variability in water properties as large as
    those associated with the PNA pattern and NAO have been observed.
    Possible aliasing and other problems resulting from the sparse
    sampling in the region has made establishing dynamical mechanisms
    and air-sea feedback difficult. Trade-offs between in situ and
    remote sampling of upper layer characteristics in data poor regions
    must be evaluated to develop cost-effective network designs.
    Combinations of modeling and empirical network design efforts are an
    integral part of developing detection/attribution capabilities.

    NOAA/OAR/ERL (Environmental Research Laboratories) are active in
    long term climate research ranging from data collection to data
    synthesis, and from model development to model validation. For
    example, the Atlantic Oceanographic and Meteorological Laboratory
    and the Pacific Marine Environmental Laboratory) are engaged in
    completing the global carbon survey directed at obtaining an
    accurate benchmark inventory of CO~2~, anthropogenic CO~2~ and other
    properties. In addition, the Atlantic Oceanographic and
    Meteorological Laboratory, the Climate Diagnostics Center, and the
    Pacific Marine Environmental Laboratory are involved in the Atlantic
    Climate Change Experiment, the last field phase of the World Ocean
    Circulation Experiment. This NSF/NOAA program is concerned with
    increased understanding of the role of the Atlantic Ocean in global
    atmospheric climate. ERL scientists are also involved in the
    synthesis of these data, bringing the diverse World Ocean
    Circulation Experiment and other data-sets into a comprehensive
    picture of the present state of the ocean. Attention is directed at
    air-sea and meridional ocean fluxes of carbon, heat, and freshwater,
    and the amount of anthropogenic CO~2~ sequestered in the ocean.

    GFDL scientists are constantly improving coupled GCMs to study
    natural decadal to centennial climate variability and the effects of
    different CO~2~ scenarios. Recent activities have included: (1) The
    development of coupled models with higher computational resolution,
    leading to substantial improvements in the simulation of interannual
    to decadal climate variability; (2) fundamental improvements in the
    representation of sub-grid scale processes in ocean models; and (3)
    the simulation of the climate response to estimates of the
    time-varying radiative forcing of the Earth over the last 200 years.
    GFDL model results and results from other modeling centers are being
    compared to observations by all four ERL groups. The model-data
    comparisons are not only leading to GCM improvements but also to
    increased understanding of both the coupled air-sea system and the
    predictability of this system.

    **Issues Pertaining to Education and Human Resources**

    The Earth's climate system is extremely intricate. Clouds, ocean
    currents, solar radiation and other elements interact in a complex
    way to determine our climate. Mathematical models allow us to study
    parts of the climate system and how those parts interact. Even
    though these models include many aspects of the climate system (air,
    oceans, land, biology) partitioned into many small grid boxes, and
    may require weeks of powerful computer time to run, they are
    relatively simple when compared to the natural system. The models
    indicate that temperature could rise considerably over some areas of
    the globe due to increased emissions of greenhouse species. The
    issue is one of how accurate are these predictions.

    Despite their complexity, current models do not adequately represent
    the roles of the ocean and clouds in the climate system. These
    models do provide useful insights into the climate system. When
    attempting to make conclusions regarding long-term climate
    variability, these models require decades of precise observations to
    verify. Only now are we approaching possessing a long enough record
    of precise data to make some preliminary assessments regarding model
    predictions. Unfortunately, the long periods involved in the oceanic
    response and the large inertia of the ocean mean that any actions
    taken to reverse impacts of man on long-term climate will require
    decades to centuries before significant impacts could occur.

    **Summary**

    Observations describe variations in the climate system, whereas
    models provide a mechanism for understanding why such variations
    occur and for predicting the future evolution of the climate system.
    A three-pronged program of integrated research has been used to
    improve representation of climate processes in models and to collect
    long-term instrumental and proxy observations in the oceans: (1)
    retrieval and analysis of instrumental and paleoclimate data to
    develop the long data-sets needed for detection studies and to test
    hypotheses and develop sampling strategies; (2) collection of new
    data for continued detection efforts based on analyses and
    weaknesses of the historical data; and (3) model studies using
    historical and new data to validate and initialize simulations and
    perform attribution studies. The benefits to society of this
    approach are: (1) improved detection of climate change signals in
    the ocean; (2) improved models of natural and anthropogenic climate
    variability; (3) quantification of the predictability of long-time
    scale climate variability; and (4) reduced uncertainties in CO~2~
    warming scenarios.

    **Options for Consideration**

    In order to better understand the changes in the earth's climate and
    what types of impacts would occur, the following suggestions are
    offered:

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-   Conduct the research necessary to develop improved models of the
    coupled ocean-atmosphere system for long-term climate prediction
    purposes, including the use of proxy and paleo-indicators,
    continuation and enhancements of long-term observing programs, as
    well as conducting process research.

-   Development of programs to more effectively utilize the data and
    observations we have available now through such mechanisms as
    improved data assimilation by models and more effective merging of
    in situ and remote sensing technologies.

-   Conduct the research necessary to understand the global carbon cycle
    on a high temporal resolution (i.e., on the order of a decade)
    scale.

**GLOBAL CLIMATE CHANGE IMPACTS ON U.S. COASTAL AREAS**

**Introductory Considerations**

The United States has one of the longest and most diverse coastlines in
the world---about 158,000 kilometers (95,439 miles) of tidal shoreline
in coastal areas and the Great Lakes---and with characteristics as
different as the locations of Alaska, Florida, California, and American
Samoa. About 94,400 kilometers (59,000 miles) of this shoreline lie
around the conterminous United States, bounding some of the most
valuable and heavily used coastal areas in the world that could be
affected by climate change. Within these coastal areas lie about 38,900
square kilometers (15,000 square miles) of coastal wet­lands and 6,500
square kilometers (2,500 square miles) of developed barrier islands. The
wetlands provide habitat for numerous species of birds, are a nursery
ground for many commercial fish and shellfish; play a vital role in
extracting nutrients and toxic chemicals from water; and provide a
buffer against coastal storms. The developed barrier islands are
primarily recreational communities.

U.S. coastal areas support a variety of important economic activities,
including fisheries and aquaculture, tourism, recreation, industry, and
transportation. Coastal fisheries, for example, produce about \$3
billion in revenue to fishermen and generate \$38 billion in economic
activity nationally per annum. Seventeen million Americans who enjoy
recreational fishing, generate an estimated \$18 billion in economic
activity. Over 85 percent of travel and tourism revenues are generated
in coastal states. In Hawaii, seven million tourists generate \$9.1
billion in revenue, and in Florida, 21.6 million tourists spend \$7.9
billion and generate over 360,000 jobs mainly due to the attraction of
Florida's coasts.

**Current Stresses on Coastal Resources**

U.S. coastal areas are experiencing greatly increased pressures as a
result of rapid population growth and accompanying development.
Population growth in U.S. coastal areas is higher than anywhere else in
the country. At present, more than 50 percent of the population lives
within 130 kilometers (80 miles) of an ocean or Great Lake and
population densities within U.S. coastal areas are five times the
national average.

The effects of climate change would add to stresses that already affect
coastal areas. An estimated 40 percent of estuarine and coastal waters
is not "fishable or swimmable," primarily because of nutrients and
bacteria from urban and agricultural runoff and municipal wastewater
treatment discharges. About 40 percent of over 20 million acres of
shellfish-growing waters in estuaries are "harvest-restricted," i.e.,
commercial harvest is either prohibited or limited, due primarily to
bacterial contamination from urban and agricultural runoff and septic
systems. In addition, the effects of pollution, as well as changes in
salinity and hydrology have contributed to the loss of traditional
shellfish acreage that can no longer support shellfish along U.S.
coasts. These changes would be exacerbated by climate change. During
1996, at U.S. ocean, bay, and Great Lakes beaches, there were at least
2,596 individual closings and advisories, 16 extended (6-12 weeks)
closings and advisories, and 20 permanent (over 12 weeks) closings and
advisories. Including the days of extended closings, the total comes to
over 3,685 closings and advisories (NRDC, 1997). U.S. shorelines are
undergoing erosion from sea-level rise, natural retreat of headlands,
coastal structures, and modifications to the natural flow of rivers.

Human activities from further inland can also have a deleterious impact
on coastal resources. Effluent discharges from sewage and industrial
plants, as well as agricultural run-off, have caused significant
nutrient over-enrichment in many coastal waters. Sewage and siltation
can be significant causes of coral reef and other coastal system
degradation in Hawaii and Florida. Dams, irrigation projects, and other
water control efforts have affected coastal environments by diverting or
altering the supply of water, sediment, or nutrients to a naturally
balanced ecosystem.

Intensive residential and commercial development of coastal areas,
particularly dynamic, storm-prone areas such as barrier islands, puts
life and property at risk and creates substantial financial liabilities.
For example, there are currently an estimated 276,000 households located
in high-hazard areas threatened by storm surge, and an additional 2.4
million households located in the flood plain adjacent to this high-risk
zone. In addition, between 1970-89, almost half of all new residential,
commercial, and industrial construction occurred in coastal counties and
was not always built to standards to withstand major storms. Infrequent,
yet high intensity storms that impact coastal areas, in conjunction with
poor construction, can result in billions of dollars of damages,
particularly where development occurs in low-lying areas. The cost of
damage from Hurricane Andrew (in Florida and Louisiana) was \$25
billion, and the combined costs for Hurricanes Hugo (South Carolina),
Opal (Florida), and Fran (North Carolina) totaled \$3 billion. While a
majority of damage from these storms was due to poor construction of
infrastructure and buildings, costs from coastal storms could be reduced
or prevented by making better decisions about the location and type of
development in coastal areas.

**Key Strategic Issues Concerning Coastal Areas and Climate Change**

Throughout time, climate change has affected the coastal environment and
will continue to do so in the future. However, human activities and
alterations have rendered coastal resources more vulnerable to climate
change-induced processes, such as accelerated sea-level rise,
alterations of rainfall patterns and storm frequency or intensity, and
increased siltation. Climate change and a rise in sea level or changes
in storms or storm surges could result in the increased erosion of
shores and associated habitat, increased salinity of estuaries and
freshwater aquifers, altered tidal ranges in rivers and bays, changes in
sediment and nutrient transport, a change in the pattern of chemical and
microbiological contamination in coastal areas, and increased coastal
flooding.

Some coastal ecosystems are particularly at risk, including saltwater
marshes, coastal wetlands, coral reefs, coral atolls, and river deltas.
Other critical coastal resources, such as mangroves and sea-grass beds,
submerged systems including submerged aquatic vegetation , and mudflats,
are at risk from climate change impacts, and exacerbated by
anthropogenic factors. Changes in these ecosystems could have major
negative effects on tourism, freshwater supplies, fisheries, and
biodiversity that could make coastal impacts an important economic
concern. These impacts would add to modifications in the functioning of
coastal oceans and inland waters that already have resulted from
pollution, physical modification, and material inputs due to human
activities. Secondary impacts associated with climate change, such as
inundation of waste disposal sites and landfills that in turn will
reintroduce toxic materials and increased siltation into the
environment, also pose threats to the health of coastal populations and
ecosystems.

Global sea levels have been rising since the conclusion of the last Ice
Age approximately 15,000 years ago. During the last 100 years, sea-level
rise has occurred at approximately 1-2.5 mm/yr. This figure represents
eustatic sea level (the absolute elevation of the Earth's ocean) that
has been determined from tidal stations around the globe. However, there
are large regional variations due to: subsidence, isostatic (glacial)
rebound, tectonic uplift, etc., that contribute to a "relative"
sea-level rise. For example, within the U.S., portions of the Gulf Coast
are experiencing a relative sea-level rise of 10 mm/year. Concurrently,
the coast of Alaska is experiencing a negative relative sea-level fall
of up to 8 mm/year; i.e. sea level is receding. Figure 7 illustrates the
change in sea level along U.S. coasts as determined from historical
tidal data. If this historical rate of sea-level rise is projected to
2100, sea level would rise 10-27 cm globally. A recent EPA study
assessed the probability of sea level rise along various U.S. coastal
towns and estimated that there is a one percent change of a 120 cm rise
and a 50 percent chance of a 55 cm rise in sea level by the year 2100
along the New York coast.

Rising global temperatures could further raise sea level by expanding
ocean water, melting alpine and other small glaciers, and perhaps
eventually causing the polar ice sheets of Greenland and Antarctica to
melt into the oceans. The most recent IPCC assessment (1995)

forecasts a rise in global sea level of 5 mm/year, within a range of
uncertainty of 2−9 mm/year with almost all of the contribution resulting
from thermal expansion and melting small glaciers. The IPCC predicts
low, mid, and high estimates of 20, 49, and 86 cm. This current best
forecast represents a rate of sea-level rise that is still about two to
five times the rate experienced over the last 100 years. Furthermore,
even if greenhouse-gas concentrations are stabilized, model projections
show that sea level will continue to rise beyond the year 2100 due to
lags in response to climate change. Figure 8 indicates the potential
impact of a 50 cm sea-level rise, or approximately the mid-range IPCC
estimate, in South Florida.

The IPCC estimates are based on the effects of thermal expansion of the
ocean. They do not include the possible contribution that the melting of
the Greenland and Antarctic ice sheets

![](media/image6.emf){width="6.260416666666667in" height="5.25in"}

![](media/image7.emf){width="6.260416666666667in"
height="5.229166666666667in"}

would have on sea-level rise. While still debated and somewhat
speculative, such melting would provide a much greater contribution to
global sea-level rise.

Coastal land, including buildings, transportation infrastructure, and
recreational and agricultural areas, is vulnerable to inundation and
increased erosion as a result of climate change. All lowlands are
threatened by a rise in sea level. Estuaries are also threatened by
potential

hydrologic changes that could increase the range of saltwater intrusion
as well as alter the amount of freshwater reaching an estuary. If a
one-meter rise in sea level occurs during the next century, the
worst-case IPCC scenario, thousands of square miles could be lost,
particularly in low-lying areas such as the Mississippi delta, where
land is also subsiding at a rate of approximately one meter per century.
Table 1 indicates the estimated land loss for seven regions of the
United States. Storm damage is expected to also increase, particularly
along the well-developed and low-lying Atlantic and Gulf of Mexico
coasts.

Assessing total economic impacts from sea-level rise on coastal areas
and on a national scale is still somewhat speculative. Nevertheless, a
recent study has quantified the present value of the economic costs
(protection plus abandonment) to coastal structures with a 1-meter
sea-level rise as \$6.4 billion between 1996 and the year 2100. However,
this figure represents only market-valued estimates which are derived
from property-value appreciation, market adaptation, and protection
costs. Thus, it is a minimum cost estimate which does not include the
lost service value of non-market resources, such as tidal wetlands.
Estimates of impact on such resources are more difficult to quantify
because they lie outside the traditional market and have not yet been
thoroughly measured. Natural systems, like a tidal wetland, can provide
flood control, storm protection, and waste recycling and have tremendous
value when measured economically.

Coastal erosion is already a widespread problem in the United States.
For example, in Oahu, Hawaii, over the past 50 years a quarter of the
beaches have been lost or significantly degraded due to causes that are
poorly understood. Heightened storm surge could increase the rate of
erosion. The highest-risk areas are those with very low relief and
currently experiencing rapid erosion rates, such as the southeastern
United States and the Gulf Coast (see Figure 9). Coastal areas would
also be more vulnerable to hurricanes, as well as to increased or
decreased freshwater and sediment flux from river systems.

Rising sea-level will, in general, increase storm surge flooding by the
level of sea-level rise, making every coastal storm appear more intense.
However, some areas will experience dramatic changes---going from no
flooding to extensive flooding. Many coastal features, such as levees,
seawalls, and naturally occurring sand dunes and ridge lines effectively
block storm surges for most storms. Whenever one of these features is
overtopped by storm surge from either a hurricane or an extratropical
storm, the areas inland will flood. Numerical modeling has shown that
large amounts of water can move over such barriers, flooding over the
marshland or bay behind the barrier, and sweeping over mainland areas.

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height="3.7604166666666665in"}

![](media/image9.emf){width="6.260416666666667in"
height="4.458333333333333in"}

Many coastal structures were designed with the 100-year flood as their
basis. This flooding level determines the elevations to which the
federal projects (such as U.S. Army's Corps of Engineers levees that
protect New Orleans) are built. It is also the level to which coastal
structures must be built to qualify for flood insurance through FEMA's
Flood Insurance Program. If sea level rises, the statistics used to
design these structures change. A 50-year flood may become as severe as
(or even more severe than) a 100-year flood before sea-level rise.
Coastal insurance rates would be adjusted to reflect such increased
risk. Furthermore, FEMA estimates that with a sea-level rise of one
meter, the number of households in the coastal floodplain would increase
from 2.7 million to 6.6 million by 2100. This growth will be the result
of sea-level rise as well as the increase of coastal population. In some
areas however, structures will be upgraded as sea level rises so that
flood risks will not increase.

Coastal wetlands are already eroding in most states (see Table 2),
particularly Louisiana and Maryland. For example, Louisiana's coastal
area lost an estimated 3,950 square kilometers of wetlands from 1930 to
1990. This loss of wetlands resulted, for the most part, from
flood-protection levees along the Mississippi and artificial bank
stabilization efforts to confine the flow of the river and prevent the
flooding, sedimentation, and freshwater supplies that occurred
naturally. Many wetland losses elsewhere result from draining or
filling. In addition, large areas of brackish and freshwater wetlands
have become progressively more saline as salt water has increasingly
invaded the deteriorating coastal zone. Because 40 percent of U.S.
coastal wetlands are found in Louisiana, this loss constitutes about 80
percent of the total national coastal wetland loss. Louisiana coastal
wetlands are exceptionally valuable in terms of coastal fisheries and
migratory waterfowl, protection of low-lying population centers from
hurricanes and other

storms, and oil and gas production. Furthermore, the greatly accelerated
rates of coastal wetland loss appear to be the unintended result of
massive human disturbances of these wetlands and intervention (for
purposes of flood protection, water supply, maritime commerce, energy
production, and wildlife management) in the processes that sustain
coastal wetlands.

Wetlands require a delicate balance of sediment, fresh and salt water
and are particularly vulnerable to inundation and erosion as a result of
sea-level rise. Coastal wetlands are also vulnerable to changes in the
source or decreased flux of fresh water and sediment, if upstream areas
become more arid. Wetlands naturally migrate as land subsides and
sediment supply changes, but migration has been limited in several areas
by the encroachment of urban areas which utilize sea walls and other
protective structures. In addition, the possible rate of sea-level rise
predicted by some climate change models is more rapid than the natural
rate of wetland migration, thus wetland losses will likely increase.

Estuarine beaches are also at particular risk to sea-level rise. They
are much more vulnerable than ocean beaches because they tend to be
narrower and policies against shoreline armoring generally apply to
oceans but not to bays. Also, they are more vulnerable than vegetated
wetlands because the wetland protection programs tend to focus on the
total area of wetlands protected and because beaches are narrow, they do
not represent much acreage. The loss of these beaches would effect
species such as horseshoe crabs and the birds that feed on them, as well
as terrapins, least terns, and tiger beetles.

**Table 2.** Regional and National Wetland Losses for the Trend and 1.0
Meter Sea Level Rise Scenarios (percent loss of current area) (from
Titus, et al., 1991).

Trend 1.0 Meter

Current \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Region Wetland Area (sq mi) Standard(**a**) Total(**a**) Standard(**a**)
None(**a**)

Mid-Atlantic 746 -5 70 46 38

South-Atlantic 3814 -2 64 44 40

South/Gulf

Coast of Florida 1869 -8 44 8(**b**) 7(**b**)

Louisiana (**c)** 4835 52 85 85 85

FL Panhandle,

AL, MS, and TX 1218 22 85 77 75

West (**d)** 64 -111 56 -688 -809

United States 13,145 17 66 49 50

Confidence Intervals:

95% Low \-- 9 50 29 26

95% High \-- 25 82 69 66

Note. A negative number indicates a gain in wetlands.

**a** Total protection refers to all shores being diked or bulkheaded;
standard protection refers to only currently developed areas being
protected.

**b** Results are not statistically significant; sampling error exceeds
estimate of wetland lost.

**c** An evaluation of the management options currently contemplated for
Louisiana (e.g. restoring natural deltaic processes) was outside the
scope of this study.

**d** This anomalous result is from small sample size. The impact on the
nationwide results is negligible.

Climate change also has the potential to significantly affect coastal
biological diversity. It could cause changes in the population sizes and
distributions of species, alter the species composition and geographical
extent of habitats and ecosystems, and increase the rate of species
extinction. Fragile systems such as coral reefs are highly susceptible
to temperature increases. Short-term increases in water temperatures on
the order of only 1-2°C, combined with other environmental stresses
(such as pollution or siltation from human activities), can cause
"bleaching," leading to significant reef destruction. Reefs in many
parts of the world, including the United States, have undergone episodes
of bleaching, particularly in the 1980s. Sustained increases of 3-4°C
above long-term average seasonal maximums can cause significant coral
mortality. Biologists suggest that full regeneration of these coral
communities could require several centuries.

Fisheries in estuaries and the coastal ocean are also vulnerable to
changes in water temperature and fresh­water inflow. The loss of coastal
wetlands has already been implicated in the decline of shrimp harvests
in Louisiana, and would also likely reduce yields of crab and menhaden.
Projections of general circulation models suggest that freshwater
discharge from the Mississippi River to the coastal ocean will increase
20 percent if atmospheric carbon dioxide concentrations doubles. This is
likely to affect water column stability, surface productivity, and
global oxygen cycling in the northern Gulf of Mexico, which is already
suffering from persistent hypoxia. In the open ocean, increased
temperatures could result in a shifting of the geographical distribution
of certain species. Decreasing freshwater flow, when combined with
rising sea level could result in the encroachment of saltwater species
into typically freshwater habitats. For example, in estuaries, decreased
freshwater inflow could result in increased salinity and, in turn, a
replacement of some freshwater species by saltwater species.

**Management Issues and Strategies**

Management strategies in coastal areas can be divided into three
categories:

\(1\) ***Accommodate.*** Vulnerable areas continue to be occupied,
accepting the greater degree of effects, e.g., flooding, saltwater
intrusion, and erosion; advanced coastal management used to avoid the
worst impacts; improved early warning of catastrophic events; and
building codes modified to strengthen structures

\(2\) *Protect.* Vulnerable areas, particularly population centers,
high-value economic activities, and critical natural resources, are
defended by sea walls, bulkheads, saltwater intrusion barriers; other
infrastructure investments are made; and "soft" structural options such
as periodic beach re-nourishment, landfill, dune maintenance or
restoration, and wetlands creation are carried out

\(3\) *Retreat.* Existing structures and infrastructure in vulnerable
areas are abandoned, inhabitants are resettled, government subsidies are
withdrawn, and new development is required to be set back specific
distances from the shore, as appropriate.

The cost-effectiveness of these adaptation strategies is enhanced to the
extent that they are planned and implemented in the context of
integrated coastal management programs carried out at various levels of
government.

Integrated coastal management is a continuous, iterative, adaptive, and
consensus-building process comprised of a set of related tasks, all of
which must be carried out to achieve a set of goals for the sustainable
use of coastal areas, including adapting to the effects of climate
change (Bower, Ehler, and Basta, 1994). The dimensions of integrated
coastal management include:

-   Integration of policies and programs across and among sectors of the
    economy---e.g., economic development, transportation, recreation,
    and agriculture

-   Integration among agencies involved in coastal management at all
    levels of government, including both vertical (national,
    subnational, and local) and horizontal (across the same level of
    government) integration

-   Integration between public- and private-sector management activities

-   Integration between management actions that affect the land and
    water environments of coastal areas, and areas upstream and upwind
    of coastal areas.

-   Integration among the disciplines of coastal management, including
    ecology, economics, engineering, and political science.

At the federal level, agencies such as the U.S. Environmental Protection
Agency have produced a number of studies which have begun to look at
projected global climate change impacts on specific resources such as
wetlands and to consider possible response options.

Individual states have used all three management strategies. Beach
re-nourishment has been prominent in heavily developed areas (e.g.,
Miami, Florida and Ocean City, Maryland) where existing investments and
the income generated by beach users is considered greater than the costs
of the re-nourishment projects. Sea walls are often built to protect
lives and property, but the trade-off is often the loss of usable
beaches and other habitats. Most of these actions are taken to address
current conditions and needs.

State and local government responses to future accelerated sea level
rise scenarios include:

\(1\) taking accelerated sea-level rise into account when filling
wetlands for water-dependent facilities (ports)which requires an
applicant to raise the fill level so facilities will not have to be
abandoned during their 50-100 year life expectancy (San Francisco Bay
Conservation and Development Commission);

\(2\) raising the elevation of new facilities such as sewage treatment
plants to protect the integrity of the facility's use (Massachusetts
Water Resources Authority);

\(3\) incorporating sea-level rise into setback laws for larger
facilities which goes beyond the normal incorporation of only historical
rates of erosion (Maine Coastal Zone Management Program);

\(4\) passing legislation in support of a retreat policy that normally
prohibits sea wall construction to allow backward migration of a beach
(North and South Carolina Coastal Zone Management Programs).

To support state coastal management efforts, the Coastal Zone Management
Act was amended in 1990 to further encourage state efforts to
incorporate the problems of climate change and sea-level rise into their
programs under natural hazards.

In February 1997, the U.S. Country Studies Program and NOAA sponsored an
international workshop in Chinese Taipei that developed guidelines for
integrating coastal management and climate change adaptation strategies.
These can serve as a guide for coastal nations to implement or
strengthen an Integrated Coastal Management program, and simultaneously
meet the obligations of international agreements.

**Status of the Relevant Science and Technical Base**

Continued investments in research and monitoring at the national and
international levels are needed to improve the information base for
adapting to climate change. For example, coastal wetlands naturally
migrate in response to changes in sediment supply and relative sea
level. However, it is unknown if the rate at which wetlands can
naturally migrate is sufficient for the possible rates of sea-level rise
that would be caused by climate change. Establishing locations for
wetlands to migrate to by expanding reserves and protected areas
adjacent to current coastal wetlands can facilitate adaptation. Creation
or restoration of wetlands is another adaptive strategy that requires
the development of effective methods for restoring coastal wetlands and
for measuring the effectiveness of those restoration efforts.

The White House Committee on the Environment and Natural Resources
(CENR) is currently coordinating several wetland activities including
studies of recent changes in wetland systems along the eastern Gulf of
Mexico and southern Atlantic coasts, and studies of changes documented
in the Mississippi Delta---which should establish credible limits on the
ability of coastal wetlands to adapt to sea-level rise by vertical
growth. Other Committee on the Environment and Natural Resources
research related to the vulnerability and adaptation of coastal systems
include space-based geodesy studies to distinguish the long-term trends
in sea-level change due to glacial melting and ocean expansion from
effects of post-glacial rebound and active tectonics; studies that test
existing geological models of coastal erosion processes; and studies of
the frequency, magnitude, and tracks of storms.

Internationally, the Intergovernmental Oceanographic Commission of
UNESCO is coordinating the development of a Global Ocean Observing
System (GOOS). This is an intergovernmental program for the collection,
distribution, and exchange of marine and oceanographic data. One of its
principal elements, the GOOS Coastal Module, is designed to integrate
and facilitate access to in-situ and remotely sensed coastal
observations for reliable assessment, prediction and management of
coastal areas and resources.

The Global Coral Reef Monitoring Network is a major contribution to the
GOOS Coastal Module. Co-sponsored by the IOC, United Nations Environment
Programme and the World Conservation Union, the network's goal is to
improve the conservation, management, and sustainable use of coral reefs
and related coastal ecosystems by providing data and information on
trends in their biophysical status and the social, cultural, and
economic values that pertain to these ecosystems.

Two major international climate change assessments (1990 and 1995) have
been conducted by the Intergovernmental Panel on Climate Change (IPCC),
which was established by the World Meteorological Organization (WMO) and
the United Nations Environment Programme (UNEP) in 1988. These
assessments examined the available science, the magnitude of
human-induced climate change, and appropriate response options. Some
areas that require further scientific research and data include scaling
down of current general circulation models to obtain local climate
change estimates, as the current GCM resolution is too low. In addition,
sea-level rise alone is not an exclusive feature of climate change in
coastal areas. Therefore, climate change studies need to be broader,
combining the effects of sea-level rise, storminess, atmospheric
circulation change, precipitation, etc.

The IPCC 1995 assessment indicates that more work is necessary for
quantifying the social costs of climate change. Net climate change
damages include both market and non-market impacts and, in some cases,
adaptation costs. However, the non-market damages (e.g. human health,
risk of human mortality and damage to ecosystems, etc.) are highly
speculative and not comprehensive, and therefore are a source of major
uncertainty in assessing the implications of global climate change for
human welfare.

**Legal Framework**

The United States is a Party to the Framework Convention on Climate
Change that entered into force in 1994. Its major objective is to
achieve the stabilization of greenhouse gas emissions and to identify
national adaptation strategies. Article 4 of the Convention commits
nations to, among other things, develop integrated plans for coastal
zone management as part of their adaptation strategies. In response to
potential commitments and obligations under the United Nations Framework
Convention on Climate Change, many nations, including the U.S., are
preparing national climate change action plans that identify management
strategies to reduce greenhouse gas emissions. Although the United
States is not currently developing a plan for adapting to the potential
impacts of long-term climate change, such plans could be developed
within the framework of existing laws.

Any plan for adapting to sea-level rise must consider federal, state,
and local legislation. Under the common law of most states, tidal waters
up to mean high water are owned by the public. As sea level rises, the
boundaries of land ownership generally migrate inland, under state law.
State laws vary considerably both on whether property owners must allow
the shore to retreat or are allowed to erect protective measures. At one
extreme, Texas and Maine prohibit structures that protect property at
the expense of narrowing the beach; at the other extreme, Maryland's
Tidal Wetlands Act guarantees the right to erect structures to hold back
the sea.

Responses to sea level rise also depend on the type and density of
development near the shore. In most states, local master plans and
zoning laws govern land use, although state coastal zone management laws
also play a role. Maryland's Critical Areas Act and New Jersey's Coastal
Area Facilities Review Act severely restrict the density of development
in portions of their coastal zones. Several states have setback laws
requiring new structures to be a minimum distance from the shore.
Although water pollution and existing erosion hazards were the primary
impetus for these laws, they also provide a framework for a response to
sea-level rise. Setbacks are consistent with a presumption that shores
will retreat naturally. The Maryland and New Jersey statutes are
consistent with a presumption that densely developed areas will be
protected, while shorelines in undeveloped areas remain in their natural
states.

State laws on access to the shore also influence a states ability to
address rising sea level. Along ocean shores with ample public access,
such as New Jersey and Florida, public support for beach re-nourishment
and shoreline planning to maintain beaches tends to be great. Along
shores with little public access, especially bay shores, the
constituency for preserving natural shorelines tends to be less
significant.

Several federal statutes address coastal problems related to rising sea
level. Section 10 of The Rivers and Harbors Act and Section 404 of the
Clean Water Act have created a federal program of wetland protection.
Strictly speaking, federal jurisdiction only extends up to the upper
boundary of the wetlands. Nevertheless, EPA and the Corps of Engineers
have the discretion to consider sea level rise and other environmental
issues in the administration of wetland mitigation programs in which,
for example, a landowner is permitted to eliminate a strip of wetlands
in return for protecting or creating wetlands elsewhere. The Federal
Flood Insurance Act provides a comprehensive framework by which coastal
communities attempt to limit the vulnerability of property to floods.
Although the guidelines under which the program operates do not
explicitly consider sea-level rise, they influence the vulnerability of
coastal development to rising sea level. As with the wetland
legislation, the executive branch has the administrative discretion to
modify existing guidelines to prepare for rising sea level should it
decide to do so.

Perhaps the most important federal statute for addressing sea-level rise
is the Coastal Zone Management Act (as amended by Public Law 104-150).
The Act provides a comprehensive framework within which all coastal
problems can be addressed. In reauthorizing the Act in 1990, Congress
recognized the importance of this potentially new threat to the nation's
shoreline environments and encouraged coastal states and territories to
begin to address rising sea level as noted in the following sections:

***Congressional Findings:*** SEC. 302. The Congress finds that\...

\(l\) Because global warming may result in a substantial sea level rise
with serious adverse effects in the coastal zone, coastal states must
anticipate and plan for such an occurrence.

***Congressional Declaration Of Policy**:* SEC. 303. The Congress finds
and declares that it is the national policy

\(2\) to encourage and assist the states to exercise effectively their
responsibilities in the coastal zone through the development and
implementation of management programs to achieve wise use of the land
and water resources of the coastal zone, giving full consideration to
ecological, cultural, historic, and esthetic values as well as the needs
for compatible economic development, which programs should at least
provide for\...

\(B\) the management of coastal development to minimize the loss of life
and property caused by improper development in flood-prone, storm surge,
geological hazard, and erosion-prone areas and in areas likely to be
affected by or vulnerable to sea level rise, land subsidence, and
saltwater intrusion, and by the destruction of natural protective
features such as beaches, dunes, wetlands, and barrier islands,\...

\(K\) the study and development, in any case in which the Secretary
considers it to be appropriate, of plans for addressing the adverse
effects upon the coastal zone of land subsidence and of sea level rise;
and\...

\(3\) to encourage the preparation of special area management plans
which provide for increased specificity in protecting significant
natural resources,.. improved protection of life and property in
hazardous areas, including those areas likely to be affected by land
subsidence, sea level rise, or fluctuating water levels of the Great
Lakes, and improved predictability in governmental decision making\...

Many state Coastal Zone Management programs have used federal funds to
conduct studies and develop policies to this end.

In addition to its role as a regulator and financial and technical
assistance provider, the federal government also has the legal authority
to address sea-level rise in its role as a property owner. Numerous
parks and wildlife refuges are found along the coast. Under both federal
and state law, the federal government has the authority to purchase
easements to enable ecosystems to migrate, and to construct coastal
protections structures to protect government property from the effects
of erosion and storms.

**Issues Pertaining to Education and Human Resources**

Education, training, and outreach that target all sectors of society are
essential components in the successful implementation of Integrated
Coastal Management and climate change adaptation strategies. In July
1997, President Clinton launched a campaign to educate Americans about
global warming and build support for the steps necessary to deal with
it, including the United States agreement to binding reductions in
greenhouse gases that were negotiated at the international conference on
climate change during December 1997 in Kyoto, Japan. This led to a U.S.
agreement for binding reductions in greenhouse gases that were
negotiated at an international conference on climate change during
December 1997 in Kyoto, Japan. However, as a July 21, 1997 article in
the Washington Post pointed out, President Clinton faces an uphill
battle in trying to "sell the public on the urgency that, in many minds,
looms far in the future, if it exists at all." The article goes on to
say that the message is being met skeptically, and in some instances,
with outright hostility, particularly by certain U.S. industries and
labor groups which maintain that the scientific evidence is unconvincing
and the economic repercussions potentially disastrous.

Despite the scientific evidence that sea level is rising globally as a
result of climate change, many individual homeowners continue to
purchase beach-front property that is threatened even now by beach
erosion resulting from human (obstruction of natural sand replenishment
from construction of jetties, sea walls, sand mining, etc.) and natural
(storms and hurricanes) causes. In some cases, people are unaware of the
risk. In other cases, people who understand the risks are willing to
develop property in hazardous areas because the value they place on
inhabiting a shorefront home is larger than the expected damages from
erosion and storms.

The willingness of some coastal residents to accept the risks of
shorefront development are apparent in the attitudes of two people
quoted in a September 13, 1997 Washington Post article about beach
erosion in Holden Beach, North Carolina. One local resident whose home
was knocked from its foundations by Hurricane Fran decided to move her
45-year-old family home just one lot back from property purchased by her
father years ago. This lot is now beach front property due to erosion.
Her response is, "It concerns me but does not threaten me. I just feel
that it is fateit\'s the same as getting in an airplane."

Even a town official of Holden Beach, who made mitigation of coastal
erosion one of his top goals upon assuming his position, built his own
home just 1,000 feet from the ocean, in an area where erosion has been
the greatest. His attitude is \"It'll be fine for mebut my
great-grandchildren may have beach-front property." This attitude is not
uncommon, the long-term nature of the problem does not incite much
urgency to take different action now.

Well-designed public education programs should use target specific
clienteleincluding elected officials, user groups, women's groups,
school children, and the general publicto develop support for
Integrated Coastal Management and climate change action plans. Public
education ought to include informal education programs that will reach
all segments of the community, including the illiterate, who may form a
significant segment of the stakeholder population.

**Opportunities and Barriers (What Works Well and What Doesn\'t)**

While climate change impacts such as accelerated sea level rise are a
potentially major concern, state and local governments have hesitated to
address the issues effectively because of the relatively long-term
nature of the problem, scientific uncertainties and, in some cases, the
large investments required. Because of scientific debate and
uncertainties, few are willing to develop potentially costly management
strategies for which the benefits will not be realized for years to
come. Consequently, management responses to climate change impacts have
been gradual since the early 1980s, but pioneering efforts have been
important for U.S. policy makers.

In response to potential commitments and obligations under the United
Nations Framework Convention on Climate Change, many nations, including
the United States, are preparing national climate change action plans
that identify management strategies to reduce greenhouse gas emissions
and adapt to the potential impacts of long-term climate change. The
successful implementation of these plans and their management strategies
within individual countries, including the United States, will depend to
a large measure on the extent of their integration into the
implementation of other national and sectoral management plans,
including coastal management plans.

Adapting to sea-level rise and other effects of climate change will
involve important trade-offs that weigh environmental, economic, social,
and cultural values. Effects will depend not only on the local patterns
and intensity of climate change, but also on the nature of the local
coastal environment; on the human, ecological, and physical
responsiveness of the affected coastal system; and on actions in other
sectors of the coastal and national economies. Given the long time
frames involved in reducing the magnitude of global warming, it is vital
that steps be taken now to manage the impacts that almost certainly will
occur in islands and low-lying coastal areas.

**Options for Consideration**

The following suggestions are offered based on the preceding discussion:

1\. Continued investments in research, monitoring and economic methods
for quantifying the social costs of climate change are needed to improve
the information base for adapting to climate change and for coastal
management. For example, the United States should take a leadership role
in developing and advancing implementation of the Coastal Module of the
Global Ocean Observing System, and particularly one of its key elements,
the Global Coral Reef Monitoring Network.

2\. As indicated in the IPCC 1995 Assessment Report, more work is
necessary for quantifying the social costs of climate change. Net
climate change damages include both market and non-market impacts and,
in some cases, adaptation costs. However, the non market damages (e.g.,
human health, risk of human mortality, and damage to ecosystems, etc.)
are highly speculative and not comprehensive, and therefore are a source
of major uncertainty in assessing the implications of global climate
change for human welfare. In general, more work needs to be done on
environmental evaluation techniques that accurately reflect the societal
benefits of these so-called "non-market" coastal resources. It is
important to accurately quantify their benefits and account for them
properly in benefit-cost analysis in order to improve decision making.
The U.S. should play a strong role in the IPCC third assessment that is
just beginning, and particularly with regard to these quantification
methods.

3\. Areas that require further scientific research and data include
higher resolution of current general circulation models to obtain local
climate change estimates, because the current GCM resolution is too low.
In addition, sea-level rise alone is not an exclusive feature of climate
change in coastal areas. Therefore, climate change studies need to be
broader, combining the effects of sea-level rise, storminess,
atmospheric circulation change, precipitation, etc. The U.S. should
support expanded studies of this nature.

4\. A guidance document for local, state and regional offices of federal
agencies should be developed, along with a handbook on no-cost and
low-cost ways to prepare for sea level rise as part of ongoing coastal
zone management activities, including wetland permits, infrastructure,
shoreline management, land use planning, and flood insurance.

5\. Public access to the coast should be expanded, especially in
estuarine shore areas that may be eliminated by sea level rise, so that
the public can appreciate the need to protect them and build support for
management measures.

The scientific information generated from the first three above options
for consideration are particularly important to substantiate the
education initiatives necessary to galvanize the public support for
management strategies. The coastal impacts of climate change need to be
placed in the context of all the other pressures on coastal resources.
U.S. coastal areas represent some of the most valuable assets that our
nation possesses. Addressing sea level rise is but one facet of the
major challenge that the U.S. and other nations face today which is
restoring, maintaining, and enhancing the quality of coastal areas that
are under the pressures of projected population growth, coastal
development, and consumption patterns.

A major public education challenge is to convince individuals of the
urgency of the problem, the long-range implications of current actions
on coastal resources and their consequences for future generations.
However, if people can be made to appreciate the importance of coastal
resources, the many threats to them, and why management strategies are
necessary, then the prospects for successfully implementing such
strategies would be improved. Therefore, recommendations for U.S.
education efforts include:

-   Well-designed public education programs should target specific
    clienteleincluding elected officials, user groups, women's groups,
    school children, and the general publicto develop support for
    Integrated Coastal Management and climate change action plans.
    Public education ought to include informal education programs that
    will reach all segments of the community, including the illiterate,
    who may form a significant segment of the stakeholder population.

-   Training and education for Integrated Coastal Management should be
    prepared on a multidisciplinary basis, so that trainees can become
    familiar with using all the scientific information related to it.
    Universities and training and research organizations should develop
    and strengthen programs of research, education, training, extension
    services, and technical assistance that will contribute to
    continuing ICM programs. These programs should combine theory and
    practice and should emphasize the application of research to address
    important coastal management issues.

-   ICM programs require a team with skills in resource and
    socioeconomics, ecology, geomorphology, coastal engineering,
    analysis of industrial and agricultural processes, financing, and
    institutional (including legal) analyses. Climate change also
    requires skills in meteorology, physical oceanography, Earth
    science, geography, and predictive computer modeling. The most
    difficult skill to acquire is integrating the various aspects of
    analysis and defining priorities among them, and discerning the
    long-range implications of current actions.

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**DOMESTIC LEGAL REGIME**

**Contents**

-   Global Change Research Act (15 U.S.C. §§ 2921 [et]{.underline}
    [seq]{.underline}.)

-   National Climate Program Act (15 U.S.C. §§ 2901-2908)

-   National Flood Insurance Reform Act of 1994 (NFIRA)

-   National Sea Grant College Program Act (33 U.S.C. §§ 1121
    [et]{.underline} [seq]{.underline}.)

-   National Weather Service Organic Act (15 U.S.C. §§ 313)

-   NFIRA Section 577

-   Robert T. Stafford Disaster Relief and Assistance Act (42 U.S.C. §
    5121 [et]{.underline} [seq]{.underline}.)

-   Coastal Barrier Resources Act of 1982 (CBRA) (16 U.S.C. §§ 3501
    [et]{.underline} [seq]{.underline}.)

-   Coastal Zone Management Act of 1972 (CZMA) (16 U.S.C. §§ 1451
    [et]{.underline} [seq]{.underline}.)

The legal regime covering the topic of weather, climate, and natural
hazards is based on a collection of important federal statutory
authorities. The following is a brief description of some of those
authorities relating to weather, climate and natural hazards. The list
is selective and is designed to illustrate some major weather, climate
and natural hazards Acts. The list is not meant to be comprehensive.

**[Global Change Research Act]{.underline}**, 15 U.S.C. §§ 2921
[et]{.underline} [seq.]{.underline}

Subchapter I - U.S. Global Change Research Program: The purpose of this
subchapter is to provide for the development and coordination of a
comprehensive and integrated U.S. research program which will promote,
in both the domestic and international arenas, improved understanding,
assessment, prediction and response to global change. Section 2938(a)
directs the President, the Chairman of the Council, and the Secretary of
Commerce to ensure that relevant research activities of the National
Climate Program are considered in developing national global change
research efforts.

Subchapter II - International Cooperation in Global Change Research:
Section 2952(a) authorizes the President to direct the Secretary of
State, in cooperation with the Committee on Earth and Environmental
Sciences, of which the National Oceanic and Atmospheric Administration
is a member, to initiate discussions with other nations leading toward
international protocols and other agreements to coordinate global change
research activities. As noted in the Climate Change Impact on U.S.
Coastal Areas Year Of The Ocean theme paper, the U.S. is a signatory to
the U.N. Framework Convention on Climate Change, which was adopted in
1992 and entered into force in 1994. Article 5 of the U.N. Framework
Convention, "Research and Systematic Observation", provides for the
development of international and intergovernmental programs and networks
aimed at conducting research, data collection, and systematic
observation. The U.N. Framework Convention recognizes that the measures
required to address climate change will be most effective if they are
based on relevant scientific considerations, as well as technical and
economic factors, and must be continually re-evaluated in light of new
findings and research. Continued Congressional support for funding
NWS/NESDIS/OAR research is a necessary element in providing the
necessary current data and information to support such international
efforts.

**[National Climate Program Act]{.underline}**, 15 U.S.C. §§ 2901-2908

The National Climate Program Act establishes the National Climate
Program (Program) to assist in understanding and responding to natural
and man-induced climate processes and their implications. The National
Climate Program Office administers the Program under the general
guidance of the interagency Climate Program Policy Board. The Program
office oversees the implementation of a five-year plan which is prepared
in cooperation with other Federal agencies, state offices, business
groups and research and academic institutions. The Program office also
prepares an annual report to the President and authorizing committees of
the Congress; reviews participating agency budget requests and submits
an analysis of the requests to OMB; coordinates interagency
participation in international climate-related and experimental climate
forecasting activities authorized by the Act; and provides financial
assistance, primarily in the form of grants to public or private
educational institutions, state agencies, and other persons or
institutions qualified to conduct climate-related studies or to provide
climate-related services.

**[National Flood Insurance Reform Act of 1994 (NFIRA)]{.underline}**

The NFIRA established the Flood Mitigation Assistance (FMA) program. The
purpose of FMA is to plan and carry out activities designed to reduce
the risk of flood damage to structures covered under contracts for flood
insurance under this title. Section 1366 of the NFIRA assigns the FEMA
Director the authority and responsibility for carrying out the program.
42 U.S.C. § 4104c. Section 1367 establishes the National Flood
Mitigation Funds to fund FMA grants. 42 U.S.C. § 4104d.

The Flood Mitigation Assistance program, unlike the Stafford Act
programs, are pre-disaster programs. There are three types of FMA
grants. *Planning grants* assist states and communities in developing
flood mitigation plans. Under section 1366 of the NFIRA, a FEMA-
approved Flood Mitigation Plan (FMP) is required in order for a state or
community to receive a FMA project grant. *Project grants* fund eligible
flood mitigation projects. FEMA encourages states to prioritize the
mitigation activities outlined in their FMPs and fund projects that will
greatly reduce or eliminate the risk of flood damage to buildings,
manufactured homes, and other NFIP-insurable structures. Mitigation of
repetitively or substantially damaged structures is a high priority.
*Technical assistance grants* assist states in providing technical
assistance to applicants in applying for the program or in implementing
approved projects.

**[National Sea Grant College Program Act]{.underline}**, 33 U.S.C. §§
1121 [et]{.underline} [seq.]{.underline}

The Sea Grant Act authorizes the award of grants and contracts to
initiate and support programs at Sea Grant colleges and other
institutions for research, education, and advisory services in any field
related to the conservation and development of marine resources. The Sea
Grant Act also established graduate and post-graduate fellowship
programs related to ocean, coastal and Great Lakes resources.

Through the mid-1980\'s, the Sea Grant Program received funding to
strengthen the marine research and development capabilities of
developing nations. Budget pressures eventually brought an end to the
international program's appropriation. However, the current authorizing
legislation at 33 U.S.C. §1124a provides for the conduct of an
international program, although no funds are directly appropriated for
this purpose. The current legislation is considerably broader in scope
than the original program which was limited to providing technical
assistance. The Sea Grant international program encourages and promotes
international research, educational activities and technology transfers
related to ocean and coastal issues; promotes the exchange of
information and data with respect to conservation of these resources;
and encourages international collaboration with respect to marine
scientific research, including activities which improve understanding of
global oceanic and atmospheric processes. Sea Grant colleges which
include projects with international components should be encouraged, as
they may serve as pilot projects for developing a new international
initiative within the National Sea Grant College Program.

**[National Weather Service Organic Act]{.underline}**, 15 U.S.C. §§ 313

The Organic Act provides the basic authority for all National Weather
Service activities. The Secretary of Commerce (as delegated to the
Assistant Administrator for Weather Services) is directed to forecast
the weather, issue storm warnings, collect and transmit marine
intelligence for the benefit of commerce and navigation, report
temperature and rainfall conditions, and take such meteorological
observations as may be necessary to establish and record the climatic
conditions of the United States. The Organic Act also provides authority
for the operation of weather satellites.

**[NFIRA Section 577: Evaluation of Erosion Hazards]{.underline}**

The Upton/Jones amendment to the National Flood Insurance Act of 1968
(NFIP) was enacted into law in 1988, and then repealed a few years
later. This amendment allowed payment of flood insurance claims to
relocate or demolish buildings immediately threatened by erosion, prior
to the actual damages. In order to administer the program, accurate
erosion rate data was required. FEMA began in 1988 to acquire copies of
existing erosion rate data and to a limited extent generate new erosion
rate data.

Several proposals were made between 1990 and 1994 that would have
established erosion management authority within NFIP, but none
succeeded. Instead, replacing the Upton Jones amendment was section 577
of NFIRA, mandating an evaluation of erosion hazards. The study shall be
designed to assist Congress in determining whether the NFIP needs to
revise its treatment of structures at risk of erosion. Section 577 has
these three key objectives:

> 1\. Determine the amount of flood insurance claims that are
> attributable to erosion;
>
> 2\. Examine the economic impact of proposals to change the NFIP by
> denying flood insurance, or making flood insurance available at
> actuarial rates in communities having erosion hazard areas; and
>
> 3\. Examine whether the costs of mapping erosion hazard areas exceed
> the benefits to the National Flood Insurance Fund.

In addition, the study shall determine whether the expenditure of
insurance premiums to map erosion hazard areas is the most
cost-beneficial use of these funds to the NFIP.

**[Robert T. Stafford Disaster Relief and Assistance Act]{.underline},**
42 U.S.C. § 5121 [et]{.underline} [seq.]{.underline}

This Act governs almost all aspects of the federal response to natural
disasters. Once a declaration of an emergency or a disaster has
occurred, various actions by federal agencies as well as expenditures in
the form of grants are authorized.

Important for mitigation are sections 404 (42 U.S.C. § 5170c) and 409
(42 U.S.C. §5176). Section 409 of the Stafford Act requires state and
local governments to evaluate the hazards in a disaster area and take
steps to mitigate those hazards, as a condition of receiving federal
disaster assistance. The hazard mitigation plan, called a section 409
plan, is a vehicle for accomplishing this. It recommends policies,
strategies and appropriate actions to reduce future losses. It must be
submitted to FEMA for approval within 180 days of the disaster
declaration. 44 C.F.R. § 206.405(d).

Section 404 authorizes Hazard Mitigation Grants to state, tribal and
local governments and certain private, non-profit organizations to
undertake measured identified following the evaluation of natural
hazards under section 409.

FEMA has just recently determined that any county in a state in which a
natural disaster has occurred is eligible for Section 404 funding, even
if that county itself was not included in the disaster declaration. FEMA
concluded that this would better fulfill the purpose of the Hazard
Mitigation Grant Program, which is to reduce the risk of future damage
and hardship. 62 [Fed. Reg.]{.underline} 36289.

**[Coastal Barrier Resources Act of 1982]{.underline}, as
amended,(CBRA), 16 U.S.C. §§ 3501 [et]{.underline} [seq.]{.underline}**

See Ocean Living Resources 1998 Year of the Ocean Discussion Paper.

**[Coastal Zone Management Act of 1972]{.underline}**, **as
amended,(CZMA), 16 U.S.C. §§ 1451 [et]{.underline} [seq]{.underline}.**

See Marine Environmental Quality 1998 Year of the Ocean Discussion
Paper.

Section 309 of the CZMA, the Coastal Zone Enhancement Program, allows
states to compete for additional CZMA funds for development of
enhancements to their CZM programs for, among other things, coastal
hazard mitigation.

**LIST OF ACRONYMS**

AOML Atlantic Oceanographic and Meteorological Laboratory

ASRL accelerated sea-level rise

CDC Climate Diagnostics Center

CENR White House Committee on the Environment and Natural Resources

CO~2~ carbon dioxide

CPC Climate Prediction Center

CZM Coastal Zone Management

DOE Department of Energy

ENSO El Niño/Southern Oscillation (The term ENSO will be used to refer
to both a warm and a cold episode; El Niño will be used to specify a
warm episode, and La Niña will be used to specify a cold episode.)

ERL Environmental Research Laboratories

FCCC Framework Convention on Climate Change

FEMA Federal Emergency Management Agency

GCM General Circulation Model

GCRMN Global Coral Reef Monitoring Network

GEWEX Global Energy and Water Cycle Experiment

GFDL Geophysical Fluid Dynamics Laboratory

GOALS Global Ocean Atmosphere Land System

GOOS Global Ocean Observing System

ICM Integrated Coastal Management

IOC Intergovernmental Oceanographic Commission

IPCC Intergovernmental Panel on Climate Change

IRI International Research Institute for Climate Prediction

NAO North Atlantic Oscillation

NASA National Aeronautics and Space Administration

NCEP National Centers for Environmental Prediction

NOAA National Oceanic and Atmospheric Administration

NSF National Science Foundation

OAR (Office of ) Oceanic and Atmospheric Research

PMEL Pacific Marine Environmental Laboratory

PNA Pacific-North American

SAV submerged aquatic vegetation

SCPP Seasonal-to-Interannual Climate Prediction Program

SST sea surface temperature

TAO Tropical Atmosphere Ocean

TOGA Tropical Ocean Global Atmosphere

UNEP United Nations Environmental Programme

UNESCO United Nations Educational, Scientific, and Cultural Organization

VOS Volunteer Observing Ship

WMO World Meteorlogical Organization

WOCE World Ocean Circulation Experiment