Transcript Global Warming Effects on Extreme Weathers

Global Warming Effects on
Extreme Weathers
By: Christopher Chappell
December 5, 2005
Global Change and Environmental
Consequence
Global climate change is a change in the longterm weather patterns that characterize the
regions of the world. The term "weather" refers
to the short-term (daily) changes in
temperature, wind, and/or precipitation of a
region. Weather is influenced by the sun. The
sun heats the earth's atmosphere and its surface
causing air and water to move around the
planet. The result can be as simple as a slight
breeze or as complex as the formation of a
tornado
• Weather is the state of the atmosphere at a specific
•
time in a specific place. Temperature, cloudiness,
humidity, precipitation, and winds are examples of
weather elements. Thunderstorms, tornadoes, and
monsoons are also part of the weather of some places
during some seasons
Climate is defined as long-term weather patterns that
describe a region. For example, the New York
metropolitan region’s climate is temperate, with rain
evenly distributed throughout the year, cold winters, and
hot summers.
Climate Change
Climate change refers to the effect of
human-induced increase in the
concentration of greenhouse gases in the
atmosphere, enhancing the natural
greenhouse effect. Combustion of fossil
fuels, cement production and land use
changes have caused CO2 concentrations
to increase.
Types of Events and Weathers
• Wildfire
• Severe Storms
• Tornadoes
• Hurricanes
• Flooding
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Severe Thunderstorms
Severe thunderstorms are a hazard in many
parts of the world. Our understanding of their
distribution in space and time is limited by
problems in our physical understanding of the
processes, and in limitations of the observational
databases. Given those limitations, the question
of how, if at all, severe thunderstorms will
change under climate change scenarios is
difficult to answer.
Tornadoes
Tornadoes are violent, whirling funnel-shaped
windstorms that usually travel over land. When a
tornado touches the ground, it can cause great
destruction in its narrow path.
Tornadoes occur when a warm, humid air mass meets
with a cool, dry air mass. This collision sometimes
results in a powerful, swirling column of air. The
tornado's swirling winds can exceed 300 mph. Tornadoes
cause much damage by this sheer force of wind, but
they also have a strong updraft that can lift and carry
objects. Fortunately, most tornadoes are relatively weak;
only a few are devastating.
Weak
Photograph by: Marshall
Strong
Photograph
by: NSSL
Violent
Photograph
by: NSSL
Radar animation of Katrina
NOAA Satellite Image Of Katrina
Flooding
• High population densities are presently
•
concentrated near the water’s edge at several
locations throughout the region and coastal the
populations are growing
Because of the highly developed nature of the
coast within the region, a large population and
considerable private property and public
infrastructure are potentially at risk of hazardous
events (i.e. inundation and flooding) associated
with sea-level rise
Flooding due to rise in sea level
Historical
Data
Sea-level
(inches)
rise
100-year flood zone
(feet)
GCM Projections
1900 – 1997
2020s
2050s
2080s
+0.09 – 0.15
inches
4.3 – 11.7
in
6.9 – 23.7
in
9.5 – 42.5
in
+0.09 – 0.15
inches
10.9 – 29.7
cm
17.5 – 60.2
cm
24.1 –
108.0
cm
9.7 feet
9.8 – 11.5
ft
10.1 – 12.4
ft
10.4 – 13.8
ft
3.0 meters
3.0 – 3.5 m
3.1 – 3.8 m
3.2 – 4.2 m
80 – 43 yrs
68 – 19 yrs
60 – 4 yrs
100-year flood return Once per 100
(years)
years
Adaptation or Mitigation
• The human response to global climate change and climate variability
can be characterized in two ways: adaptation and mitigation.
• Adaptation involves developing ways to protect people and places
by reducing their vulnerability to climate impacts. Examples of
adaptation include building seawalls or relocating buildings to higher
ground to protect communities against increased flooding due to
storms.
• Mitigation involves attempts to slow the process of global climate
change by lowering the level of greenhouse gases in the
atmosphere. Examples include such mechanisms as planting trees
that absorb carbon dioxide from the air and store it in the soil or in
their trunks and roots.
Adaptation
A related problem is that focusing on adaptation
to local impacts of climate change without
attempting to reduce future changes to Earth's
climate is not a responsible position for a city or
region, a state, or a country. This is an issue of
good governance and responsible stewardship of
the Earth, not an issue that speaks to the self
interest of local governments or even the nation.
Benefits of Mitigation
• Improvements in local environmental
quality
• Improvements in local public health and
well-being
• Stimulation of the local economy