Agency	EPA 430-F-16-042
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What Climate Change
Means for south Carolina
South Carolina's climate is changing. Most of the state has
warmed by one-half to one degree (F) in the last century, and the
sea is rising about one to one-and-a-half inches every decade.
Higher water levels are eroding beaches, submerging low lands,
and exacerbating coastal flooding. Like other southeastern states,
South Carolina has warmed less than most of the nation. But in
the coming decades, the region's changing climate is likely to
reduce crop yields, harm livestock, increase the number of
unpleasantly hot days, and increase the risk of heat stroke and
other heat-related illnesses.
Our climate is changing because the earth is warming. Since the
late 1700s, people have increased the amount of carbon dioxide
in the air by 40 percent. Other heat-trapping greenhouse gases
are also increasing. These gases have warmed the surface and
lower atmosphere of our planet about one degree during the last
50 years. Evaporation increases as the atmosphere warms,
which increases humidity, average rainfall, and the frequency of
heavy rainstorms in many places—but contributes to drought in
Greenhouse gases are also changing the world's oceans and ice
cover. Carbon dioxide reacts with water to form carbonic acid, so
the oceans are becoming more acidic. The surface of the ocean
has warmed about one degree during the last 80 years. Warming
is causing snow to melt earlier in spring, and mountain glaciers
are retreating. Even the great ice sheets on Greenland and Ant-
arctica are shrinking. Thus the sea is rising at an increasing rate.
Temperature change (°F):
-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5
Rising Seas and Retreating Shores
As the oceans warm, seawater expands and raises sea
level. Melting ice adds more water to the ocean, further
raising sea level. In South Carolina, the land surface is
sinking, so the observed rate of sea level rise relative to the
land is greater than the global average rise in sea level. If
the oceans and atmosphere continue to warm, sea level is
likely to rise one to four feet in the next century along the
coast of South Carolina.
As sea level rises, the lowest dry lands are submerged and
become either tidal wetland or open water. To some extent,
wetlands can create their own land and keep pace with a
slowly rising sea. But in many southeastern coastal areas,
wetlands will not keep pace, and instead convert to open
water. Many species of birds, fish, and shellfish in South
Carolina depend on coastal wetlands that are threatened
by rising sea level. Salt marshes provide habitat for clams,
mussels, oysters, and other shellfish. They also provide
nurseries and feeding grounds for many fish, and provide
food for birds, such as egrets and the endangered wood
Beaches also erode as sea level rises. A higher water
level makes it more likely that storm waves will wash over
a barrier island or open new inlets. Eroding shores will
threaten homes throughout the South Carolina coast unless
people take measures to prevent shore erosion.
Rising temperatures in the last century. South Carolina has warmed less
than most of the United States. Source: EPA, Climate Change Indicators
in the United States.
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Dead trees show how the beach has eroded at Hunting Island.
© James G. Titus; used by permission.

Storms, Homes, and Infrastructure
Tropical storms and hurricanes have become more intense
during the past 20 years. Although warming oceans provide
these storms with more potential energy, scientists are not sure
whether the recent intensification reflects a long-term trend.
Nevertheless, hurricane wind speeds and rainfall rates are likely
to increase as the climate continues to warm.
Whether or not storms become more intense, coastal homes
and infrastructure will flood more often as sea level rises,
because storm surges will become higher as well. Rising sea
level is likely to increase flood insurance rates, while more
frequent storms could increase the deductible for wind damage
in homeowner insurance policies. Charleston and the barrier
islands are especially vulnerable to the impacts of storms and
sea level rise.
Changing the climate is also likely to increase inland flooding.
Since 1958, the amount of precipitation during heavy rainstorms
has increased by 27 percent in the Southeast, and the trend
toward increasingly heavy rainstorms is likely to continue.
/4s sea level rises, Charleston's streets are increasingly prone to
flooding at high tide. Credit: NOAA.
Changing the climate will have both harmful and beneficial
effects on farming. During the next few decades, hotter
summers are likely to reduce yields of corn. But higher
concentrations of atmospheric carbon dioxide increase crop
yields, and that fertilizing effect is likely to offset the harmful
effects of heat on cotton, soybeans, wheat, and peanuts—
assuming that adequate water is available. More severe
droughts, however, could cause crop failures. Higher
temperatures are also likely to reduce livestock productivity,
because heat stress disrupts the animals' metabolism.
Higher temperatures and changes in rainfall are unlikely to
substantially reduce forest cover in South Carolina, although the
composition of trees in the forests may change. More droughts
would reduce forest productivity, and climate change is also
likely to increase the damage from insects and disease. But
ionger growing seasons and increased concentrations of carbon
dioxide could more than offset the losses from those factors.
Today forests cover two-thirds of the state. Loblolly pine trees
dominate forests in most of the state, while oak, gum, and
cypress trees are common in northeastern South Carolina; and
oak and white pine are more common in the mountains.
Changing the climate may alter the composition of forests
throughout the state to more closely reflect the oak and white
pine forests found today in the mountains.
Human Health
Hot days can be unhealthy—even dangerous. Certain people are
especially vulnerable, including children, the elderly, the sick,
and the poor. High air temperatures can cause heat stroke and
dehydration and affect people's cardiovascular and nervous
systems. Seventy years from now, temperatures are likely to
rise above 95°F approximately 30 to 60 days per year in much
of South Carolina, compared with about 15 such days today.
Warmer air can also increase the formation of ground-level
ozone, a key component of smog. Ozone has a variety of health
effects, aggravates lung diseases such as asthma, and
increases the risk of premature death from heart or lung
disease. EPA and the South Carolina Department of Health and
Environmental Control have been working to reduce ozone
concentrations. As the climate changes, continued progress
toward clean air will be more difficult.
The sources of information about climate and the impacts of climate change in this publication are: the national climate assessments by the U.S. Global Change
Research Program, synthesis and assessment products by the U.S. Climate Change Science Program, assessment reports by the Intergovernmental Panel on Climate
Change, ana EPA's Climate Change Indicators in the United States. Mention of a particular season, location, species, or any other aspect of an impact does not imply
anything about the likelihood or importance of aspects that are not mentioned. For more information about climate change science, impacts, responses, and what you
can do, visit EPA's Climate Change website