lecture 12 big problems. global warming the e-m spectrum
TRANSCRIPT
Lecture 12
Big Problems
Global Warming
The E-M Spectrum
Fate of Solar Radiation Fate of Solar Radiation Reaching the EarthReaching the Earth
reflectionreflectioncloudsclouds
snow and icesnow and ice
the earth’s surfacethe earth’s surface
atmospheric dustatmospheric dust
reflectionreflectioncloudsclouds
snow and icesnow and ice
the earth’s surfacethe earth’s surface
atmospheric dustatmospheric dust
Fate of Solar Radiation Fate of Solar Radiation Reaching the EarthReaching the Earth
absorptionabsorptionatmosphereatmosphere
oceansoceans
landland
plant photosynthesisplant photosynthesis
absorptionabsorptionatmosphereatmosphere
oceansoceans
landland
plant photosynthesisplant photosynthesis
Fate of Solar Radiation Fate of Solar Radiation Reaching the EarthReaching the Earth
radiationradiationradiationradiation
The Greenhouse Effect
Greenhouse GasesGreenhouse Gases
Carbon DioxideMethane
Nitrous OxideWater Vapor
Ozone
Thousands of Years Before Present
Tem
per
atu
re C
han
ge
(oF
)
Atm
osp
her
ic C
O2
(pp
m)
Year
Temperature
Carbon Dioxide
Tem
per
atu
re C
han
ge
(oF
)
Atm
osp
her
ic C
O2
(pp
m)
Atmospheric CO2 & Surface Temperature TrendsAtmospheric CO2 & Surface Temperature Trends
Sea level rise
Increased plant primary productivity
Shifts in the distribution of plants and animals
Water contamination and outbreaks of water-borne diseases
Increased storm severity
Potential melting or enlargement of polar ice caps
Changes to patterns of rainfall
More severe droughts or increased precipitation
changes to ocean circulation patterns
Predicted changes with increased greenhouse warming
Ice Age 18,000 years ago
Sea Level Changes due to Ice Ages and Ice Cap Melting
Year
Ch
ang
es in
Mea
n S
ea L
evel
Mean Sea Level RiseMean Sea Level Rise
Summer Arctic Sea Ice Decline Comparison between 1979 & 2005Summer Arctic Sea Ice Decline Comparison between 1979 & 2005
Early Fall Arctic Sea Ice ExtentEarly Fall Arctic Sea Ice ExtentS
ea Ic
e E
xten
t (m
illio
n k
m2 )
Year
Greenland Seasonal Surface Melting
Surface melting
Permafrost
Permafrost
Permafrost melting
Permafrost melting
Permafrost melting
Drunken forest
Year
North Atlantic Tropical Storms10-year running average
North Atlantic Tropical Storms10-year running average
Nam
ed T
rop
ical
Sto
rms
1 Meter Sea Level Rise Waikiki1 Meter Sea Level Rise Waikiki
http://www.soest.hawaii.edu/HMRG/FloodingOahu/index.phphttp://www.soest.hawaii.edu/coasts/sealevel/waikiki.html
Sea Level Rise
• Destroys coastal habitat (e.g. salt marshes, mangroves)
• Destroys human property• Increases pollution• Decreases freshwater supply
Effect on Marine Life• Phytoplankton bloom due to light and
temperature cues• Changes will impact food web• Hypoxia may result
Effect on Fisheries
• Migrations are in response to temperature• May impact fisheries
Effect on Corals• Coral bleaching • Leads to loss of habitat and food for reef-
dependent species
CurrentsOceanic conveyor belt may change ocean currents • Currents carry plankton• Bring food and oxygen• Distribute eggs and larvae• Remove wastes and pollutants
Salinity• Animals have a narrow range of tolerance• Glacial melting inputs lots of freshwater
Acidity• CO2 makes water acidic• Corals and other calcium carbonate species
can’t make skeleton• Impact on plankton development impacts food
web
Temperature• Higher temperature results in less O2
- Results in hypoxia• Ice melting leaves no resting/hunting areas for
polar bears• Antarctic Krill impacts food web
Larsen B Ice Shelf
• 220 m thick• Lost 5700 km2
(2x Rhode Island)
• Reduction of 40%
Invasive Species• Algae smothers coral• Invasive species out-compete natives
Weather Events
More severe weather patterns• El Niño• Hurricanes • Mudslides• Forest Fires• Drought
Sea Surface Temperature
July 24, 2012 http://www.elnino.noaa.gov/
Origin and paths of tropical cyclones
• Tropical cyclones are intense low pressure storms created by:
– Warm water
– Moist air
– Coriolis effect
El Niño-Southern Oscillation (ENSO)
• El Niño = warm surface current in equatorial eastern Pacific that occurs periodically around Christmastime
• Southern Oscillation = change in atmospheric pressure over Pacific Ocean accompanying El Niño
• ENSO describes a combined oceanic-atmospheric disturbance
El Niño
• Oceanic and atmospheric phenomenon in the Pacific Ocean
• Occurs during December• 2 to 7 year cycle
Sea Surface Temperature
Atmospheric Winds
Upwelling
Normal conditions in the Pacific Ocean
El Niño conditions (ENSO warm phase)
La Niña conditions (ENSO cool phase; opposite of El
Niño)
El NiñoNon El Niño
1997
Non El Niño
El Niño
thermocline
upwelling
El Niño events over the last 62 years
82-83
65-6672-73
57-5886-87 91-92
94-95
97-98
02-0309-10
Red - Strong El NinoBlue- Strong La NinaBlack – moderate (either)
50-5155-56
64-65
70-71
73-74
75-7688-89
98-9999-00
07-08 10-11
11-12
1969 1951 1957 1950 1955 1973
1976 1963 1965 1954 1970 1975
1977 1968 1972 1956 1998 1988
2004 1986 1982 1962 2007 1999
2006 1987 1997 1964 2010
1991 1967
1994 1971
2002 1974
2009 1984
1995
2000
El Niño La Niña
Weak Mod Strong Weak Mod Strong
2011
Effects of severe El Niños
• Ozone (O3) protects life on earth from the damaging affects of ultraviolet radiation (UV)
• Natural produced by sun’s energy in stratosphere and lightening
• Ozone destroyed by CFC’s
• Studies suggest that the ozone layer hasbeen gradually “thinning” since 1975.
Human activities are depleting the atmospheric ozone
Ultraviolet Radiation
“A threat to the continuation of life”2
Humans: DNA damageCancer
Crops: Productivity decreaseOcean plants: Death?
VisibleInfrared (IR) UV
Ultraviolet Radiation
stratosphericozone layer
CFCs: refrigerationelectronics
foam packagingspray propellants
destroy
UV
‘96: CFC decrease noticed2006: stabilization?
‘96: CFC decrease noticed2006: stabilization?
Antarctic Total Ozone Trend
400
1950 1960 1950 1950 1950 1950 2010
300
200
100
0
To
tal o
zon
e (
Dob
son
uni
ts)
Ozone blocks UV
Oct. 1979
Oct. 2011
Size of the Antarctic ozone holeAverage Area: millions sq km
North AmericaNorth America
AntarcticaAntarctica
Prediction: 50 years to return to 1980 size
1979 2001
30
20
10
0
Natural Phenomena
Upperatmosphereresearch satellite
Volcanicemissions?
Sea spray?
Directevidence
Directevidence
sunspots
Why is it Important?
Early Warning
If global warming, likely more serious consequences
Nuclear Contamination
3
SEVERE
HIGH
ELEVATED
GUARDED
LOW
Ocean Dumping
total > 10 million Curiestotal > 10 million Curies
Three Mile Island (‘79) = 17 CuriesChernobyl (‘86) = 100 million CuriesFukushima (2011) = 60 million Curies
US
Other
Switzerland
GreatBritain
USSR
Arctic Ocean
Russia
Soviet Union’s Atomic Dumping Ground
Moscow
Human Population Growth
CrowdingResource depletionWater shortagesEpidemic diseasesFood supply limitations
“Population Wars”
4
World Population
0
2,000
4,000
6,000
8,000
10,000
12,000
1500 1700 1900 2100
estimates(millions)
Year
How is the trend changed?
How is the trend changed?
Can Society Respond
• Has society become skeptical
• Must we assign blame
• Is there leadership
• Can we get multinational agreements
• Can we afford it
Questions
• CFC’s contribute to:• Major gasses involved in global warming
are:• Global warming may result in these
environmental consequences:• A severe El Nino can cause _______ in
California.• Much of Russia’s nuclear waste is stored
_______.