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Global Warming
CO2 needs to be added to the list!
• Not regulated as a
pollutant under the
U.S. Clean Air Act.
– But most emissions
are CO2
• A greenhouse gas
– Contributes to
global climate
change
In the US…
Sources of C02
• US emissions
1. 40 %
Petroleum
products
2. 34 % coal
3. 20 % natural
gas
Greenhouse Effect
• In a greenhouse, light enters but IR cannot
escape
• CO2 in atmosphere allows light rays to enter
but traps IR
• CO2 % in atmosphere has increased from 280
ppm in pre-Industrial time to present day
value of 375.64 ppm (2003 data), 387 ppm
(2009 data)
Rise in atmospheric CO2 in the last 50 years
Why the see-saw pattern? Why Mauna Loa?
Other Greenhouse Gases
• Methane, water vapor, nitrous oxide
– Rice paddy, extraction of fossil fuel, raising of live
stock (bovine flatulence) cause increase in methane
– Cutting of forests kills CO2 sink
• Some effects might be opposite of CO2: SO2
Increasing concentration of
greenhouse gases
Gas
Historic Level
Current Level
Warming
potential
comapred to
CO2
Lifetime in
Atmosphere
(years)
CO2
280 ppm
387 ppm
1
5-200
CH4
700 ppb
1720 ppb
23
12
N2O
275 ppb
314 ppb
300
114
CFCs
0
ppt level
4000-8000
5-100
Perfluoromethane (PFC)
40 pt
80 ppt
5700
50,000
Sulfur
Hexafluoride
(SF6)
0.01 ppt
3 ppt
22,000
3200
Greenhouse Effect: Is it Real?
• How much CO2=How much rise of T?
• More T = more evaporation = more cloud = Less
Temp…
• Real rise or natural fluctuation?
– Data for the last 10ka indicate upto 6 °C fluctuation
– Little ice age (1450 – 1850)
– About 2/3rd of the centuries warming has taken place in
the last 25 years: 1990s were the warmest decade of the
20th century
– Based on 14,000 land and sea records from all over the
world
– Ice core patterns –varied between 180 and 280 ppm in the
last half million years
Evidence to Support Global Warming
• Intergovernmental Panel on Climate Change (IPCC)
– An international panel of scientists and government officials
established in 1988
– Generated reports on the synthesis of scientific information
concerning climate change
– 4th Assessment report 2007
• Documents observed trends in surface temperature, precipitation
patterns, snow and ice cover, sea levels, storm intensity
• The IPCC concluded that it is more than 90%
likely that most global warming is due to humans
– The Debate over climate change is over
– 84% of people surveyed think humans contribute to global warming
• Predicts future changes
Effects of Global Warming
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•
•
•
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Sea level rise
Extreme weather
Decreasing Biodiversity
Decline in Food Production
Effect on Health
Greatest air pollution problem: Global Warming
•
www.nelson.wisc.edu/outreach/energy2006
Greenhouse Effect: Problems
• Increasing ocean temperature:
– 0.06 C between 1955 and 1995
– Oceans hold 10X heat than what has been used to raise
the global temperature
– An increased amount of heat storage in the oceans
preceded all earlier rapid warming
• Rise of temperature : Drier climate?
•Satellites that detect and observe different
characteristics and features of the Earth's atmosphere,
lands, and oceans are often referred to as environmental
satellites.
•Most environmental satellites have one of two types of
orbits: geosynchronous (GOES) or sun-synchronous
(POES)
Sea Surface Temperature
• Sea surface-temperature is one important type of
data that GOES and POES provide.
• Temperature changes influence the behavior of
fish, can cause the bleaching of corals, and
affects weather along the coast.
• Satellite images of sea-surface temperature also
show patterns of water circulation. Examples
include locations of upwelling, characterized by
cold waters that rise up from the depths, often
near the coasts; and warm water currents, such
as the Gulf Stream.
Steve Riser and ARGO lab
•3000 free floating package of sensors
•Crates a ocean temperature map upto 1500 m depth
Temperatures will rise 0.2 degree Celsius per decade
• Global Sea level rise:
– Thermal Expansion = 57%
– Melting of glaciers = 28%
– Melting at Antarctica and Greenland = 15%
• Melting of Glaciers:
–
–
–
–
–
–
Alaska: 3 C rise in temp in the last 30 years
Glaciers melting at alarming rate
Contributed at least 9% of global sea-level rise
Permafrost melting – decomposition of vegetation  rise in CO2
Kilimanjaro – 82% of the snow cap has melted
Very rapid melting of glaciers in the Himalaya and in the Andes
• If all the ice melted sea level will rise by 75m inundating 20% of the
Earth’s land area. No Florida!!
• Even a partial melting of Antarctica ice cap will raise sea level by 3 to
6m. Fear of calving from Ross Ice Shelf
• Globally sea-levels rose 10-20 cm in the 20th century – 10X faster
than the last 3000 years
• 1 m rise = 1 billion people displaced
NASA image of Greenland Ice melting
Low coastal areas lost 3X more ice due to melting and
ice berg formation than high interiors
Area of surface melting across the Greenland Ice Sheet, as
inferred from satellite observations of the surface temperature.
IPCC predicts mean sea level to be a meter
(100 cm) or more higher than today’s at the
end of the 21st century
Global Warming
KEY FINDINGS (National Assessment Synthesis
Team)
1. Increased warming
Assuming continued growth in world greenhouse gas emissions, the climate
models used in this Assessment project that temperatures in the US will rise 5-10ºF
(3-6ºC) on average in the next 100 years.
2. Differing regional impacts
Climate change will vary widely across the US. Temperature increases will vary
somewhat from one region to the next. Heavy and extreme precipitation events are
likely to become more frequent, yet some regions will get drier. The potential
impacts of climate change will also vary widely across the nation.
3. Vulnerable ecosystems
Ecosystems are highly vulnerable to the projected rate and magnitude of climate
change. A few, such as alpine meadows in the Rocky Mountains and some barrier
islands, are likely to disappear entirely, while others, such as forests of the Southeast,
are likely to experience major species shifts or break up. The goods and services lost
through the disappearance or fragmentation of certain ecosystems are likely to be
costly or impossible to replace.
4. Widespread water concerns
Water is an issue in every region, but the nature of the vulnerabilities varies, with
different nuances in each. Drought is an important concern in every region. Floods
and water quality are concerns in many regions. Snowpack changes are especially
important in the West, Pacific Northwest, and Alaska.
5. Secure food supply
At the national level, the agriculture sector is likely to be able to adapt to climate
change. Overall, US crop productivity is very likely to increase over the next few
decades, but the gains will not be uniform across the nation. Falling prices and
competitive pressures are very likely to stress some farmers.
6. Near-term increase in forest growth
Forest productivity is likely to increase over the next several decades in some areas
as trees respond to higher carbon dioxide levels. Over the longer term, changes in
larger-scale processes such as fire, insects, droughts, and disease will possibly
decrease forest productivity. In addition, climate change will cause long-term shifts
in forest species, such as sugar maples moving north out of the US.
7. Increased damage in coastal and permafrost areas
Climate change and the resulting rise in sea level are likely to exacerbate threats
to buildings, roads, powerlines, and other infrastructure in climatically sensitive
places, such as low-lying coastlines and the permafrost regions of Alaska.
8. Other stresses magnified by climate change
Climate change will very likely magnify the cumulative impacts of other stresses,
such as air and water pollution and habitat destruction due to human
development patterns.
For some systems, such as coral reefs, the combined effects of climate change
and other stresses are very likely to exceed a critical threshold, bringing large,
possibly irreversible impacts.
9. Surprises expected
It is very likely that some aspects and impacts of climate change will be totally
unanticipated as complex systems respond to ongoing climate change in
unforeseeable ways.
10. Uncertainties remain
Significant uncertainties remain in the science underlying climate-change impacts.
Further research would improve understanding and predictive ability about societal
and ecosystem impacts, and provide the public with useful information about
adaptation strategies.
Shift in Predictions
from two models
•By 2030, Illinois will have
a climate like Missouri’s.
•By 2090, it will have a
climate like Oklahoma’s.
•Resultant shift in
ecological communities,
agriculture patterns…
•Up to 30% of land based
animal and plant species
might disappear
•Hardest hit will be coldclimate-communities e.g.,
polar bears
•Coral Reefs will be hard hit
Green = Canadian model
•More Forest fires – more
Blue = Hadley model
CO2, loss of biodiversity
Kyoto Protocol
• Conference: Dec 1-11, 1997 in Kyoto, Japan
• Six Greenhouse gases were targeted (CO2, CH4, NOx, CFCsubstitutes)
• Their emission to be reduced below 1990 levels as follows:
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–
–
–
–
–
–
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EU: 8%, US: 7%, Japan 6%
The reduction will be done in a 5 year period between 2008-2012
Emission can be traded in global market
Creation of carbon sinks like afforestation can be balanced against
emission
Developing countries to benefit from “clean” technology
The protocol will be open for signature in March, 1998, has to be ratified
by countries producing 55% of the emissions: reached in 2004 after Russia
signed it.
Entered into force: Feb 16, 2005 US pulled out of it in 2001
187 countries around the world have signed and ratified the protocol.
USA, under the leadership of President Bush has withdrawn from Kyoto
Protocol stating it will ‘hurt US economy’ and has made no move to ratify
it as of today.
Participation in Kyoto Protocol as of June 2009
Where are we heading to?
USA with 4% of world population produces 25% of CO2
Halting emissions
• California’ s Global Warming Solutions Act
• Cut greenhouse gas emissions 25% by 2020
• 10 NE states launched the Regional Greenhouse Gas Initiative (RGGI) in
2007
• cap-and-trade program for C emissions from power plants
Fig. 15-22, p. 371