United States	AliOUSt 2016
Environmental Protection
t. Agency	EPA 430-F-16-023
What Climate Change
Means ^Massachusetts
The climate of Massachusetts is changing. The commonwealth
has warmed by more than two degrees (F) in the last century.
Throughout the northeastern United States, spring is arriving
earlier and bringing more precipitation, heavy rainstorms are more
frequent, and summers are hotter and drier. Sea level is rising, and
severe storms increasingly cause floods that damage properly
and infrastructure. In the coming decades, the changing climate is
likely to increase flooding, harm ecosystems, disrupt fishing and
farming, and increase some risks to human health.
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
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 others.
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
Increasing Temperature and Changing
Precipitation Patterns
Rising temperatures and shifting rainfall patterns are likely to
increase the intensity of both floods and droughts. Average
annual precipitation in the Northeast increased 10 percent
from 1895 to 2011, and precipitation from extremely heavy
storms has increased 70 percent since 1958. During the
next century, average annual precipitation and the frequency
of heavy downpours are likely to keep rising. Average
precipitation is likely to increase during winter and spring,
but not change significantly during summer and fall. Rising
temperatures will melt snow earlier in spring and increase
evaporation, and thereby dry the soil during summer and fall.
So flooding is likely to be worse during winter and spring, and
droughts worse during summer and fall.
Sea Level Rise, Wetland Loss, and Coastal
Rising sea level erodes wetlands and beaches and increases
damage from coastal storms. Tidal wetlands are inherently
vulnerable because of their low elevations, and shoreline
development prevents them from migrating inland onto
higher ground. Human activities such as filling wetlands have
destroyed about one third of New England's coastal wetlands
since the early 1800s. Wetlands provide habitat for many bird
species, such as osprey and heron, as well as several fish
species. Losing coastal wetlands would harm coastal ecosys-
tems and remove an important line of defense against coastal
Rising temperatures in the last centuiy. Massachusetts has warmed
almost twice as much as the rest of the contiguous 48 states.
Source: EPA, Climate Change Indicators in the United States.
The marshes of Plum Island Estuary are among those predicted to
submerge in the next centuiy. Credit: Matthew Kirwan, USGS.

Sea level rise, stronger storms, and coastal erosion threaten parts of the
New England coastline such as these homes in Newburyport. Credit:
Irish Gairigan, EPA,
Coastal cities and towns will become more vulnerable to storms
in the coming century as sea level rises, shorelines erode, and
storm surges become higher. Storms can destroy coastal homes,
wash out highways and rail lines, and damage essential commu-
nication, energy, and wastewater management infrastructure. In
the city of Boston alone, the total cost of storm damages during
the 21st century could be between $5 and $100 billion, depend-
ing on how the city responds to rising sea level.
Ecosystems and Natural Resources
Changing the climate threatens ecosystems by disrupting
relationships between species. Wildflowers and woody perennials
are blooming—and migratory birds are arriving—sooner in
spring. Not all species adjust in the same way, however, so the
food that one species needs may no longer be available when
that species arrives on its migration. Warmer temperatures allow
deer populations to increase, leading to a loss of forest
underbrush, which makes some animals more vulnerable to
predators. Rising temperatures also enable invasive species to
move into areas that were previously too cold.
Parts of Massachusetts^ fishing and farming sectors may suffer
as the climate changes. Rising water temperatures can lower
oxygen levels and otherwise alter freshwater and marine
ecosystems. Some species such as bass may flourish more
readily in the Northeast's warming waters, but key ocean
fisheries, such as cod and lobster south of Cape Cod, are
expected to decline. The loss of coastal wetlands could harm
bass, clams, and other commercially important fish. Climate
change may also pose challenges for agriculture: Some farms
may be harmed if more hot days and droughts reduce crop
yields, or if more flooding and wetter springs delay their planting
dates. Other farms may benefit from a longer growing season
and the fertilizing effect of carbon dioxide.
Human Health
Changes in temperature and precipitation could increase the
incidence of acute and chronic respiratory conditions such as
asthma. Higher temperatures can increase the formation of
ground-level ozone (smog), a pollutant that can contribute to
respiratory problems. Rising temperatures may also increase
the length and severity of the pollen season for plants such as
ragweed. Certain people are especially vulnerable, including
children, the elderly, the sick, and the poor.
The risk of some diseases carried by insects may also increase.
The ticks that transmit Lyme disease are active when tempera-
tures are above 45°F, so warmer winters could lengthen the
season during which ticks can become infected or people are
exposed to the ticks. Higher temperatures would also make more
of New England warm enough for the Asian tiger mosquito, a
common carrier of West Nile virus. The number of cases may or
may not increase, depending on what people do to control insect
populations and avoid insect bites.
Increase in Lyme disease between 1996 and 2013. Each dark dot
shows one case reported in 1996; light dots show 2013. The increased
range shown here has been attributed to factors other than climate
change. Nevertheless, additional wanning will lengthen the season
during which people are exposed to Lyme disease and may allow the
disease to spread to colder areas. Source: CDC.
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, assessment reports by the Intergovernmental Panei 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 iikelihood 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.eDa.aov/climatechanae.