£%	United States
Environmental Protection
LI M % Agency
What Climate Change
Means Alabama
August 2016
EPA 430-F-16-003
In the coming decades, Alabama will become warmer, and the state
will probably experience more severe floods and drought. Unlike
most of the nation, Alabama has not become warmer during the last
50 years. But soils have become drier, annual rainfall has increased
in most of the state, more rain arrives in heavy downpours, and sea
level is rising about one inch every eight years. Changing the climate
is likely to increase damages from tropical storms, reduce crop
yields, harm livestock, increase the number of unpleasantly hot days,
and increase the risk of heat stroke and other heat-related illnesses.
Rising Seas and Retreating Shores
Sea level is rising more rapidly in Alabama than most
coastal areas because the land is sinking. If the oceans
and atmosphere continue to warm, sea level along the
Alabama coast is likely to rise eighteen inches to four feet
in the next century. Rising sea level submerges wetlands
and dry land, erodes beaches, and exacerbates coastal
Our climate is changing because the earth is warming. People have
increased the amount of carbon dioxide in the air by 40 percent
since the late 1700s. Other heat-trapping greenhouse gases are also
increasing. These gases have warmed the surface and lower atmo-
sphere of our planet about one degree (F) 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 others. While most
of the earth warmed, natural cycles and sulfates in the air cooled
Alabama. Sulfates are air pollutants that reflect sunlight back into
space. Now sulfate emissions are declining, and the factors that
once prevented the state from warming are unlikely to persist.
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 Antarctica
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
Changing temperatures in the last century. While most of the nation
has warmed, Alabama and a few other states have cooled. Source:
EPA, Climate Change Indicators in the United States.
Coastal 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. Many cities, roads, railways, ports, airports, and
oil and gas facilities along the Gulf Coast are vulnerable
to the combined impacts of storms and sea level rise.
People may move from vulnerable coastal communities
and stress the infrastructure of the communities that
receive them.
Hurricane Katrina's storm surge destroyed homes and roads on
Dauphin Island in 2005. Credit: FEMA.

Precipitation and Water Resources
Annual precipitation in Alabama has increased 5 to 10 percent
since the first half of the 20th century. Although rainfall during
spring is likely to increase during the next 40 to 50 years, the
total amount of water running off into rivers or recharging ground
water is likely to decline 2.5 to 5 percent, as increased evapo-
ration offsets the greater rainfall. Droughts are likely to be more
severe, because periods without rain may be longer and very hot
days will be more frequent.
Flooding, River Transportation, and Hydroelectric
Flooding is becoming more severe in the Southeast. 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. While some
rivers such as the Tennessee have dams to help prevent
flooding, other rivers either have no dams or have dams with
too little capacity to significantly reduce flooding. Heavy rains
have caused the Pea River to flood Elba several times, and the
Alabama River flooded two thousand homes in Selma and
Montgomery during 1990.
Droughts create a different set of challenges. When reservoirs
release water for navigation along the Tennessee or Black Warrior
rivers, too little water may be available for lake recreation or
hydropower. Low flows from drought occasionally limit navigation
along the Alabama River. During severe droughts in the Missis-
sippi River's watershed, however, navigation can potentially
increase on the Tennessee-Tombigbee Waterway, which provides
an alternative route to the Gulf of Mexico.
Flooding of a small stream in June 2014 destroyed this roadbed in
Foley. Credit: Patsy Lynch, FEMA.
Droughts also affect the amount of electricity that Alabama
Power and the Tennessee Valley Authority (TVA) can produce
from their hydroelectric dams, which account for about 8 percent
of the electricity produced in the state. During the 2007 drought,
total production from the TVA's hydroelectric plants fell by more
than 30 percent, which forced the TVA to meet customer
demand by using more expensive fuel-burning power plants.
Agriculture and Forest Resources
Changing the climate will have both harmful and beneficial
effects on farming. Seventy years from now, Alabama is likely to
have 30 to 60 days per year with temperatures above 95°F,
compared with about 15 days today. Even 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 soybeans, cotton, wheat, and
peanuts—if 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 Alabama, 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
longer growing seasons and increased carbon dioxide concen-
trations could more than offset the losses from those factors.
Forests cover more than two-thirds of the state. Oak, hickory,
and white pine trees tend to be most common in the northern
part of the state, while loblolly pines are more common in the
southern forests. As the climate warms, forests in southern
Alabama are likely to have more white pines and oaks, and
fewer loblolly pines.
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. 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 Alabama Department of Environmental
Management have been working to reduce ozone concentrations.
As the climate changes, continued progress toward clean air
will become more difficult.
The sources of information about ciimate 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, and 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 at www.epa.aov/climatechanae.