Ozone

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San Joaquin Delta

• REDUCED SNOWPACK
• HIGHER SEA LEVEL
• LESS RAINFALL

CA aqueduct
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Mean Predicted Changes 2080 2099 Scenario
A1B
Dry belts at /- 30 latitude Hadley cells
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Example of glacier retreat Glacier AX010, Nepal
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Antarctica Larsen B ice shelf collapse
Jan 31 2002
March 5 2002
Area of loss is the size of Rhode Island Ice
shelves are partially supported on land, so some
net sea level rise Distinguish the ice shelf
from an ice sheet formed on land
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West Antarctic Ice Sheet
Size of sheet depends on a balance between
influx from snowfall and outflow at the
boundary to the sea Crevasses form, and
meltwater flows to the base of the sheet,
lubricating it and increasing outflow Shelves
extend out into the sea as they melt and break
up, the glaciers accelerate a movement toward
the sea This is happening in both Greenland
and West Antacrtica
inland retreat
Science 315, 1503-1504 (2007)
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Greenland and Antarctic Ice Cap Elevation
changes
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Arctic Sea-Ice Cover September 2007
Science 318, p. 33 (2007) Annual sea ice
minimum (September) is on a steady decrease
Huge drop in 2007 led to opening of the
Northwest Passage Complete loss in the summer as
early as 2030 ??
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Anticipated opening of the arctic ice new
national claims on arctic, eyes on petroleum
development
Drilling rig in the Beaufort Sea
Science 315, 1525-28 (2007)
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Causes of sea level changes
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Sea level change predictions also depend on the
choice of Scenario
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Prediction of sea level changes

• Difficult to make
• Vary depending on models and assumptions (Western
  Antarctic Glacier)
• New results suggesting much higher changes
• Impacts are multiple and can be combined with
  other effects (e.g., extreme weather events, El
  Nino strengthening)

Melting of either the Greenland ice cap or the
West Antarctic ice sheet would raise sea
levels about 6 meters Science 311, 1698-1701
(2006)
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Secondary effects on weather and storms
Virtually certain gt99 Extremely likely
gt95 Very likely gt90 Likely gt66 More likely
than not gt50 Unlikely lt33 Very unlikely
lt10 Extremely unlikely lt5
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• Impact on Coral Reefs
• Extremely high biodiversity due to nutrient-poor
  medium
• 30 billion income yield per year on fisheries
• 5 Pacific nations are based entirely on coral
  atolls
• Bleaching due to higher ocean temperatures

Corals live in symbiosis with algae
zooxanthella, which contain photosynthetic
pigments The algae are adversely affected by
the temperature increase The white color is the
coral skeleton (CaCO3) being seen through
transluscent tissue devoid of the algae 1-2 C
increase over 5-10 weeks can induce
bleaching Corals eventually die without their
symbiotic algal guests
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Other impacts of global warming -species
extinctions -migration of species Northward
(Northern hemisphere) -extension of disease
vectors into new areas
Explanation warmer Pacific Ocean led to a
higher cloud line on the Costa Rican
mountainsides Cloud line went above the tree
line on many days, so there was no mist to
provide moisture Bufo periglenes was exquisitely
adapted to the misty conditions its
permeable skin led to desiccation when the
mists left the mountain forests for too many
days
Golden toad habitat - Costa Rican cloud
forest Now apparently extinct
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Global costs of extreme weather events
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• Further potential for long-term catastrophic
  changes
• Slowing or collapse of the Gulf Stream
• Breakdown of tropical rainforests
• Release of methane hydrates from the seafloor

See Science 316, 188-190 (13 April 2007) for a
summary of the IPCC reports The working group
II report is online at www.ipcc.ch/SPM6avr07.pdf
Working group III report will be out on May 4
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• Forces driving ocean circulation tides, winds,
  and density differences
• Thermocline from solar heating warm surface and
  cold deep (75-200 m.)
• Tavg above thermocline 18C Tavg below
  thermocline 3C

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• Surface waters in Atlantic cool as they move
  toward the North
• Thermocline disappears at the poles surface and
  deep waters mix
• Surface is saltier at the poles (salt is excluded
  from ice when it freezes)
• Density increases with salt ? net downward
  movement at poles
• Deepwater current created, carrying water south
• Danger melting polar ice will disrupt the polar
  salt gradient and
• shut the whole circulation down

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Predicted changes after collapse of the Gulf
Stream freeze-out in North Atlantic
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Rainforest collapse
Plants take up CO2 in photosynthesis As CO2
increases, plant stomata (admitting and releasing
gas) stay closed a greater percentage of the
time Open plant stomata are also essential for
release of water, leading normally to high
levels of tropical rainfall Reduced rainfall,
coupled to other climate changes as CO2
increases, lead to rainforest collapse in some
computer models
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1 GtC (gigaton carbon) 109 metric tons
1012 kg 1015 grams (1 petagram Pg) 1 Tg
(teragram) 1012 grams
Fast exchange

• Methane hydrates
• Caged CH4 trapped
• in permafrost and
• in marine sediments
• near-offshore
• Very large amounts
• thought to exceed
• total of all other
• fossil fuels
• Potential resource but
• expensive to extract

Slow exchange
Permanent sink
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This scenario is very unlikely in the next
century But thawing of the Arctic permafrost and
large-scale CH4 release is possible without
coupling to sea level rise
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Where are the CO2 emissions presently coming from?
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Air Pollution Regulatory solutions

• Tall smokestack laws a local but not a
  regional/international solution
• Clean Air Act (CAA) and 1990 Amendments SO2 is
  a criteria pollutant.
• (one of six others include O3, NOx, CO, fine
  particles, lead)
• Criteria pollutants have to meet National
  Ambient Air Quality Standards
• (NAAQS) max emission levels are set based on
  health
• considerations of a vulnerable population
  not based on
• economic and technical considerations
• One size fits all standard, but tempered by
  flexibility in
• State implementation (SIP state
  implementation plan)
• Works in the US as the mandating legislation to
  ensure clean air
• Mass. v EPA (2007) US Supreme Court rules EPA
  has regulatory jurisdiction
• over CO2 emissions and can include them
  within the CAA.
• Trading a market-based solution.
• Implemented under the Clean Air Act
• Very successful for acid rain, and a model for
  global policy

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Air pollution Regulatory solutions

• Trading a market-based solution.
• Issue continued economic growth means more new
  SO2 sources
• How to accommodate this while maintaining
  NAAQS?
• Bubbling A required reduction in emissions is
  met over an entire
• facility allows less efficient stacks to keep
  operating
• Netting Increase emissions at one source but
  compensate by
• decreasing them at another
• Trading rights to pollute 3 steps
• (i) Govt. agency sets a total acceptable
  emissions level
• (ii) allocates pollution allowances among
  facilities
• (iii) establishes rules for the exchange of
  allowances

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Air pollution Regulatory solutions

• Cap and trade
• (i) Govt. agency sets a total acceptable
  emissions level
• (ii) allocates pollution allowances among
  facilities
• (iii) establishes rules for the exchange of
  allowances
• Facilities that cannot reduce emissions cheaply
  can buy allowances from
• those that can, so a market is established and
  costs are reduced.
• Offsets create a bubble over an air quality
  region, then a new source may
• not start up until it buys allowances from
  existing sources. If a region
• is in nonattainment, the offset ratio is set
  higher than 11.
• Buying and selling occurs in the Chicago Board of
  Trade
• Acid rain Rewards allowances for companies that
  implement clean coal
• technology those companies can then sell the
  allowance on the market
• Costs of allowances much lower than initially
  feared scrubbing technology
• Has functioned efficiently to reduce SO2
  emissions causing acid rain

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The cap and trade program has worked very well
Sulfate Ion Concentrations 1985-2004
1985
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Sulfate Ion Concentrations 1985-2004
1989
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Sulfate Ion Concentrations 1985-2004
1994
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Sulfate Ion Concentrations 1985-2004
1999
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Sulfate Ion Concentrations 1985-2004
2004
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Regulatory Response to Climate Change

• 1988 United Nations Environment Program (UNEP)
  and
• World Meteorological Organization (WMO) create
  the IPCC
• IPCC charge assess the scientific, technical,
  and economic basis
• for climate change. Over 2000 natural/social
  scientists
• IPCC was set up to inform the basis for policy,
  which was then created by the
• 1992 Framework Convention on Climate Change
• few specific and substantive obligations
• parties should stabilize GGs at levels that
  would prevent dangerous
• anthropogenic interference
• parties defined in several categories, with
  Annex I industrialized
• countries having obligations to adopt
  national policies to
• mitigate climate change
• no legally binding target, but a requirement to
  provide detailed
• information, with the aim of returning to 1990
  levels

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Regulatory Response to Climate Change
1995 IPCC Report balance of evidence
suggests a discernible human influence on global
climate -a catalyst for the 1997 Kyoto
Protocol -provided support to take politically
difficult measures -getting to 1990-level GG
emission targets already difficult 1997 Kyoto
Protocol -quantified emissions limitation and
reduction objectives for Annex I countries.
Europe agreed to lower emissions to 8 below
1990 U.S. agreed to lower to 7 below
1990 -reduction targets were to be met by
2012 -transitioning countries could choose a
later year for their target -no emissions
reduction targets for developing
countries -general guidelines for emissions
trading, compliance and monitoring -generalized
language left many ambiguities
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Regulatory Response to Climate Change
1997 Kyoto Protocol -general guidelines for
emissions trading, compliance and
monitoring -includes Clean Development Mechanism
to help developing countries meet their
targets. Developed countries or private
companies fund activities in developing
countries get credit for an emissions reduction
-Developed countries opposed, fearing a carbon
cartel, yet were unwilling to meet all
required reductions by means of cutting their
own emissions. -Includes setting up emissions
trading buying/selling of carbon
credits Implementation of Kyoto -required 55
parties representing at least 55 of total CO2
emissions -Among Annex I countries, only US and
Australia have refused to ratify -Over 140
countries have ratified -Entered into force in
February 2005 after Russia signed on -Even though
implemented, it is very unclear how targets will
be met
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• Bali roadmap December 2007
• Purpose is to set agenda for negotiations to
  decide on what
• to replace Kyoto accords with (Kyoto expires in
  2012)
• Reduction of tropical deforestation will count as
  a carbon credit
• Rich nations must provide verifiable, measurable
  and reportable
• technological aid to developing countries
• Verifiable emissions cuts 25-40 of 1990 level
  by 2020
• were desired by EU, others, but not
  specifically included