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FUNDAMENTALS OF
GLOBAL CLIMATE CHANGE
Physical Causes
Consequences
Prevention, Mitigation,
Monitoring, and Adaptation
FUNDAMENTALS OF
GLOBAL CLIMATE CHANGE
Physical Causes
PLANET EARTH
PHYSICAL INTERACTIONS OCCUR
ON MANY SCALES
• Propagation, reflection, and
refraction of light and EM waves from
the sun (creating the solar input)
• Absorption, storage, and re-radiation
of light and EM waves (causing the
“natural” greenhouse effect).
• Absorption of heat by greenhouse
gases in the atmosphere (causing the
“Unnatural” greenhouse effect).
WHAT DOES IT ALL MEAN?
• THE “NATURAL” GREENHOUSE
EFFECT KEEPS THE EARTH WARM AT
ABOUT 57.9 DEGREES F, AND
• THE “UNNATURAL”GREENHOUSE
EFFECT CAUSES THE ATMOSPHERE’S
TEMPERATURE TO RISE, FOLLOWED
BY A RISE IN LAND AND OCEAN
TEMPERATURES, CAUSING CLIMATE
CHANGE ON A GLOBAL SCALE
THE GREENHOUSE EFFECT
OCCURS WHEN AN EARTH
WARMED BY THE SOLAR
SPECTRUM RADIATES
INVISIBLE INFRARED LIGHT
BACK, BUT…
CONTINUED
…INSTEAD OF GOING BACK
TO SPACE, IT IS PARTLY
ABSORBED BY
GREENHOUSE GASES IN THE
ATMOSPHERE
 NOTE: ABSORPTION MAKES
THE ATMOSPHERE WARMER.
A WARMING EARTH: SEPT 25, 2007
THE AVERAGE GLOBAL
TEMPERATURE HAS RISEN 1.7
DEGREES F IN PAST 150 YEARS
2005 - HOTTEST YEAR ON RECORD
• According to NASA and other
organizations, 2005 was the
hottest year on record for the
Northern Hemisphere.
• Temperatures were about 1.4
degrees Fahrenheit above the
historical average.
SATELLITE MEASUREMENTS
INDICATE THAT THE TROPOSPHERE IS WARMING FASTER
THAN THE EARTH’S SURFACE.
 NOTE: THIS INDICATES THAT
GREENHOUSE GASES IN THE
ATMOSPHERE ARE ABSORBING
TOO MUCH HEAT.
SOLAR INPUT
 After hitting Earth's
upper atmosphere,
about one - third of
the sun's energy is
reflected back into
space.
 The two-thirds that
gets through the
atmosphere drives
Earth's weather
engine
THE SUN PROVIDES AN
AVERAGE OF ABOUT 1370
WATTS OF POWER THROUGH
EM RADIATION TO EVERY
SQUARE METER OF SURFACE IT
STRIKES.
 NOTE: THIS IS CALLED THE
SOLAR CONSTANT.
THE SOLAR SPECTRUM
INCLUDES: VISIBLE LIGHT
(ROYGBI), ULTRAVIOLET
LIGHT (A WAVE LENGTH TOO
SHORT TO SEE), AND
INFRARED LIGHT (A WAVE
LENGTH TOO LONG TO SEE).
ABOUT 33 PERCENT OF
THE INCOMING SOLAR
SPECTRUM IS REFLECTED
BACK TO SPACE FROM
CLOUDS, SNOW, AND, TO
A LESSER DEGREE, BY
LAND SURFACES..
THE BALANCE (ABOUT 70
PERCENT) OF THE
INCOMING SOLAR
SPECTRUM IS ABSORBED
BY LAND, AIR, WATER, OR
ICE.
THE OCEANS STORE HEAT
Oceans, the source
of moisture in the
air, store heat more
effectively over the
long term than land
and transports it
efficiently over
distances of
thousands of miles.
•
THE EARTH’S OCEANS
ABSORB 20 TIMES AS MUCH
HEAT AS THE EARTH’S
ATMOSPHERE.
•
THE pH LEVEL OF THE
EARTH’S OCEANS HAS
INCREASED.
 NOTE: THE pH INCREASES AS
CARBON DIOXIDE IS ABSORBED.
SEA LEVEL RISES FOR TWO
REASONS:
 WATER EXPANDS WHEN IT
IS WARMED, AND
 WATER VOLUME
INCREASES AS MELT
WATER IS ADDED.
AVERAGE GLOBAL SEA
LEVEL HAS INCREASED BY
4.7 INCHES SINCE THE
LAST ICE AGE.
•
•
IF THE FLOATING ARCTIC ICE
CAPS MELT, GLOBAL SEA
LEVEL WILL NOT BE AFFECTED.
IF ALL THE SNOW AND ICE IN
GREENLAND MELTED, GLOBAL
SEA LEVEL WILL RISE 24 FEET.
CLOUDS CAUSE BOTH
COOLING AND WARMING
 Clouds cool Earth by
reflecting incoming
solar energy.
 Clouds cool Earth by
slowing evaporation.
 Clouds warm Earth by
trapping heat being reradiated upward from
the Earth’s surface.
LAND SURFACES AFFECT
TEMPERATURES AND MOISTURE
Mountain ranges
can block clouds,
creating "dry"
shadows
downwind.
 Sloping land
facilitates water
runoff, leaving
the land and air
drier.
ICE AND SNOW
Ice and snow
reflects heat
outward into space,
cooling Planet Earth
in the process.
When ice melts into
the ocean, the
ocean water losses
some of its stored
heat.
THE ALBEDO (PERCENT
OF LIGHT REFLECTED)
FOR FRESH SNOW IS 80-90
PERCENT,
 BUT IT IS ONLY 50 – 60
PERCENT FOR MELTING
ICE.
GREENHOUSE GASES IN THE
ATMOSPHERE
 “Greenhouse"
gases include
water vapor,
carbon dioxide,
methane and
nitrous oxide.
WATER VAPOR
Higher air
temperatures
increase the rate
of water
vaporization.
Water vapor is
the most potent
greenhouse gas.
VOLCANIC ERUPTIONS
Volcanic
eruptions
add water
vapor and
ash to the
atmosphere.
“UNNATURAL”GREENHOUSE
EFFECT
 Greenhouse gases
trap heat inside the
atmosphere.
 Too much trapped
heat increases
temperatures in the
atmosphere and on
the land and ocean
surfaces, which
causes climate
change.
•
•
THE GREENHOUSE EFFECT
OCCURS NATURALLY.
HUMAN ACTIVITIES
EXACERBATE THE “UNNATURAL”
GREENHOUSE EFFECT BY
INCREASING CERTAIN
GREENHOUSE GASES (E.G., CO2)
ABOVE HISTORIC LEVELS.
•
WITHOUT THE “NATURAL”
GREENHOUSE EFFECT,
PLANET EARTH WOULD BE
MUCH COLDER; E.G., A
TEMPER-ATURE OF ABOUT
MINUS 2 DEGREES F.
•
WITH AN “UNNATURAL”
GREENHOUSE EFFECT,
PLANET EARTH WOULD BE
WARMER THAN THE
CURRENT AVERAGE
TEMPERATURE OF 57.9
DEGREES F.
CARBON DIOXIDE ENTERS
THE ATMOSPHERE
NATURALLY, AND
NATURE REMOVES CARBON
DIOXIDE FROM THE
ATMOSPHERE NATURALLY.
THE OCEANS ARE A
NATURAL CARBON SINK
The oceans and
marine life
remove and/or
consume huge
amounts of
carbon dioxide.
•
AS THE GREENHOUSE
EFFECT INCREASES
TEMPERATURES IN THE
ATMOSPHERE, THE
REMOVAL RATE OF
CARBON DIOXIDE IS
DECREASED.
HUMAN INFLUENCES
 Humans are
exacerbating warming
by adding much more
carbon dioxide to the
greenhouse gases that
are naturally present in
the atmosphere,
through ….
 Extensive use of fossil
fuels.
HUMAN INFLUENCES
 Aerosols, smoke and
sulfates reflect
sunlight away from the
Earth, which outweigh
----.
 The temporary,
localized cooling
effects from aerosols
and the smoke and
sulfates from industry.
HUMAN INFLUENCES ON LAND
SURFACES
 Once tropical forests
(a carbon sink) are
cleared for cattle
ranching or community
development, the
cleared land can
becomes a major
source of methane, a
greenhouse gas.
FUNDAMENTALS OF
GLOBAL CLIMATE CHANGE
Consequences
THE WATER CYCLE AND THE
“UNNATURAL” GREENHOUSE EFFECT
Higher air
temperatures
increase the rate of
water vaporization
(Water vapor is the
most potent
greenhouse gas)
and accelerate the
melting of ice.
.
THE CONSEQUENCES OF
GLOBAL CLIMATE CHANGE
• Worldwide rise in sea level.
• Collapse of the Atlantic thermohaline
circulation (“The Atlantic Conveyor Belt”).
• Increased probability of severe windstorms.
• Larger storm surges in seasonal hurricanes
and typhoons.
• Prolonged droughts in some regions and
heavy precipitation in others.
THE CONSEQUENCES OF
GLOBAL CLIMATE CHANGE
• Reduced fresh water for a large
portion of humankind that
presently obtains its fresh
water from glacier-fed rivers.
• Loss of function of activities
such as winter ski resorts.
ATLANTIC THERMOHALINE
CIRCULATION
• The Atlantic Conveyor Belt keeps
Europe from becoming a deep
freeze in the winter.
• Ancient sediments, ice cores, and
fossils indicate that the Atlantic
Conveyor Belt shifted abruptly
about 8,200 years ago, when a
sudden cooling occurred.
ATLANTIC CONVEYOR BELT
• As a result, the land
temperature in Greenland
dropped more than 9 degrees
Fahrenheit within ONE OR
TWO decades, an effect that
could prove disastrous for
Europe.
GREENLAND’S ICEBERGS
GREENLAND
• Greenland's glaciers are melting into the
sea twice as fast as the previously
calculated rate of four miles per year.
• This faster rate, if continued in concert
with similar observations in the
Himalayas and South America, makes
predictions of how quickly Earth's
oceans will rise over the next century
questionable and probably obsolete.
GREENLAND AND ANTARCTICA
• The ice sheets in Greenland and
Antarctica are among the largest
reservoirs of fresh water on Earth.
• How much sea level will rise as a
result of faster melting is unclear.
• Current estimates of around 50 cm
(20 in) over the next century may be
much too low.
DECREASING ICE THICKNESS AT
QUELCAYA, PERU
GLACIAL RETREAT: COLOMBIA
GLACIAL RETREAT:
BALAIS, SWITZERLAND
GLACIAL RETREAT: GLACIER
NATIONAL PARK, MONTANA
SHEPHARD GLACIER: 1913
(LEFT) AND 2005 (RIGHT)
GRINNELL GLACIER: 1938
(LEFT) AND 1991 (RIGHT)
CORAL BLEACHING
• Ocean temperatures that are too warm
stress corals, causing them to expel
symbiotic micro-algae—their food
supply-- which lives in their tissues.
• As a result, the reefs appear bleached.
• Bleaching that lasts longer than a week
can kill corals.
• One of the significant long-term impact is
on the fishing industry.
CORRAL BLEACHING FROM
TEXAS TO TRINIDAD
FUNDAMENTALS OF
GLOBAL CLIMATE CHANGE
Prevention, Mitigation,
Monitoring, and Adaptation
THE TIPPING SCENARIO ISSUE
OF GLOBAL CLIMATE CHANGE
• The “Tipping Scenario Issue”
is:
• Within a few decades, will
humans be virtually helpless
to slow, much less, reverse
the risks associated with
global warming?
THE TECHNOLOGY ISSUE OF
GLOBAL CLIMATE CHANGE
• “The Technology” issue is: “Can
the global community slow and
possibly reverse the perceived
increasing adverse risks through
timely technological innovations
for prevention, mitigation,
monitoring, and adaptation?”
RISK ASSESSMENT
•MEASUREMENTS
• MAPS
•INVENTORY
•VULNERABILITY
•LOCATION
DATA BASES
AND INFORMATION
ACCEPTABLE RISK
RISK
UNACCEPTABLE RISK
LOCAL &
REGIONAL
SCALES
ANTICIPATORY
DECISIONS
GLOBAL CLIMATE
CHANGE
HAZARDS:
GROUND SHAKING
GROUND FAILURE
SURFACE FAULTING
TECTONIC DEFORMATION
TSUNAMI RUN UP
AFTERSHOCKS
•PREVENTION/MITIGATION
•MITIGATION
•MONITORING
•ADAPTATION
Living with Global Climate Change
NO DISASTER :
INCREASED
DEMANDS ON
COMMUNITY
INCREASED
CAPABILITIES OF
COMMUNITY
Living With Global Climate Change
A DISASTER :
DECREASED
CAPABILITIES OF
COMMUNITY
INCREASED
DEMANDS ON
COMMUNITY
Prevention, Mitigation and
Adaptation Measures
• PREVENTION
(CONTROL THE
SOURCE)
• MITIGATION
(REDUCE THE
IMPACTS)
• ADAPTATION
(ANTICIPATE)
Measures (continued)
• MONITORING
• SCENARIOS
• ADAPTATIVE
RESPONSE TO
MONITORING AND
SCENARIOS
ADAPTATION: THAMES RIVER,
LONDON
•A report of the U.S. Climate Change Science
Program, a joint effort of more than a dozen
government agencies
•The full report is online at www.usgcrp.gov
•June 20, 2008
•"Heat waves and
heavy downpours are
very likely to increase
in frequency and
intensity.”
"Substantial areas of
North America are likely to
have more frequent
droughts of greater
severity.”
•
“ Hurricane wind
speeds, rainfall
intensity, and storm
surge levels are likely
to increase.”
•
The cold season storms are
likely to become more
frequent, with stronger winds
and more extreme wave
heights."
•
Soil amplification of
earthquake ground
shaking is likely to be
more pervasive.
•
Landslides triggered in
earthquakes are likely
to be more extensive.
•
The effects of tsunami
wave run up will be
more extensive.
•
“By the end of this century
rainfall amounts expected to
occur every 20 years now
could be taking place every
five years.”
Such an increase "can lead to
the type of severe floods that
we are seeing at present in the
Midwest.“
•
•The heavy rains fell on a
landscape that had been
radically reengineered by
humans for 50 years.
•Plowed fields have replaced tall
grass prairies.
•Former prairie grass fields
were meticulously drained with
underground pipes.
•Streams and creeks were
straightened.
Most of the former wetlands
were gone.
• Community development
had taken over former
floodplains.
•
w
• Comprehensive
emergency
management will be more difficult
to plan and implement in the future.
• Sustainable infrastructure will also
be difficult to plan and achieve.