Greenhouse Gasses

1
Greenhouse Gasses in order of importance

• water vapor
• carbon dioxide
• methane
• nitrous oxide
• ozone
• CFCs

2
Changes in greenhouse gas concentrations

• Historical variations can be tracked via analysis
  of ice cores
• Ice core - a core sample (a cylindrical section
  of a naturally occurring medium consistent enough
  to hold a layered structure) from the
  accumulation of snow and ice over many years that
  have re-crystallized and have trapped air bubbles
  from previous time periods.
• The composition of these ice cores provides a
  picture of the climate at the time.
• Record for over 800,000 years

Gas Preindustrial Level
Current Level Increase since 1750 Carbon
dioxide 280 ppm 387ppm
104 ppm Methane
700 ppb 1,745 ppb
1,045 ppb Nitrous oxide 270 ppb
314 ppb 44 ppb CFC-12
0
533 ppt 533 ppt
3
What do the ice cores tell us?

• Natural variations occur in the greenhouse gas
  concentrations

4
Post industrial revolution
5
Man made sources of greenhouse gasses

• Also called Anthropogenic, which designates an
  effect or object resulting from human activity
• burning of fossil fuels and deforestation
  leading to higher carbon dioxide concentrations.
• Account for one third of total anthropogenic CO2
  emissions.
• livestock enteric fermentation and manure
  management, paddy rice farming, land use and
  wetland changes, pipeline losses, and covered
  vented landfill emissions leading to higher
  methane atmospheric concentrations. Many of the
  newer style fully vented septic systems that
  enhance and target the fermentation process also
  are sources of atmospheric methane.
• use of chlorofluorocarbons (CFCs) in
  refrigeration systems, and use of CFCs and halons
  in fire suppression systems and manufacturing
  processes.
• agricultural activities, including the use of
  fertilizers, that lead to higher nitrous oxide
  (N2O) concentrations.

6
What are we seeing?

• Since 1860-1900, global surface temperatures have
  increased by 1.35 F
• Urban heat island effect only accounts for 0.02 C
  rise
• Since 1979 land T have increased twice as fast as
  ocean Temperatures
• Temperatures on the lower troposphere have have
  increased by 0.62 between 1979 and 2000.

7
Hold on, could it be the sun?

• No overall increase in solar brightness in over
  1000 years
• Solar cycles do cause small variations in
  brightness, but not enough to account for what
  has been seen
• No its not the sun

8
Feedback-making the problem worse (or better)

• Positive feedback-when the warming induces
  further warming
• Negative feedback when the warming induces a
  cooling

9
Sources of Feed back

• Positive
• Water vapor
• Clouds
• Ice albedo
• Arctic methane release
• Reduced carbon dioxide absorption in the oceans

• Negative
• Lapse rate

10
Negative feedback

• Lapse Rate
• Increased heating means increased IR emission
• Global warming reduces the rate of Temperature
  decrease with height, which means more long
  wavelength radiation will be emitted by the upper
  atmosphere
• This will weaken the greenhouse effect

11
Positive feedback

• Water vapor
• Warming increases the amount of water vapor in
  the atmosphere, which increases the warming since
  water vapor is also a greenhouse gas
• Clouds
• Act as a blanket, reflect IR radiation downward
  toward the surface
• Ice albedo
• Melting ice reveals land and water, both reflect
  less light than ice-more warmth is absorbed
  increasing warming
• Arctic methane release
• Warming releases sources of carbon dioxide
• Reduce carbon dioxide absorption in oceans
• Warm waters favor the growth of plankton rather
  than diatoms-diatoms are more efficient carbon
  dioxide absorbers

12
Global dimming

• An effect that has been counteracting some of
  global warming from about 1960 forward
• Aerosols produced by volcanoes and pollutants
  such as sulfur dioxide reflect incoming sunlight
• Soot suspended in the atmosphere, it can absorb
  solar radiation and heat the atmosphere, but cool
  the surface

13
What are we seeing

• Besides the increases in Temperature
• Worlds glaciers are melting
• Arctic sea ice is reducing in both extent ( 9
  reduction in area per decade) and thickness
  (15-40 in thickness in the last 30 years)
• Ocean levels are rising-both due to melting of
  Antarctic ice and thermal expansion of sea water
• Longer growing seasons
• Thawing of permafrost in Alaska
• Coral reef bleaching-whitening of reefs due to
  increased temperature
• Earlier plant flowering
• Earlier bird arrivals
• Shifting of animal ranges poleward
• More frequent EL Nino-warming of the Pacific
  ocean surface temperatures-causes changes in
  local weather patterns

14
Global warming-the debate

• The fact that the Earth is warming is not a
  matter of debate, the evidence is clear
• The fact that global carbon dioxide levels have
  increased is also clear
• The debate centers around how much of it is
  caused by human involvement vs a natural cycle
• Think about it in terms of the steps in the
  scientific method

15
Global warming in the context of the scientific
method

• Observations-Earths temperature is warming
• Hypothesis-due to a man-made increase in green
  house gases
• Testing the hypothesis-many scientists hold
  different views and interpret data differently,
  but the consensus is that it is due to increases
  in greenhouse gasses from man made sources.
• Until the data is incontrovertible, there will
  always be naysayers. Thats ok, they keep us
  honest and push the method forward-as long as
  they are within the realm of the scientific
  method
• Lots of examples like this in modern science
  (evolution, big bang, cosmological
  interpretations of galaxy redshifts)

16
Dissenting opinions

• American Association of Petroleum Geologists was
  the last scientific body to acknowledge human
  influence on climate change
• Individual scientists fall into 5 categories
• Believe global warming is not occurring or has
  ceased
• Believe accuracy of IPCC climate projections is
  questionable
• Believe global warming is primarily caused by
  natural processes
• Believe cause of global warming is unknown
• Believe global warming will benefit human society
• In the end, only time will tell.

17
Prognosis

• How do we know what is going to happen?
• We dont , but it can be predicted
• We call these global climate models
• Based on physics (fluid dynamics and radiative
  transfer, for eg.)
• Different models consider different effects, have
  different inputs and give a range of results
• Model validity is verified by using them to
  predict past and current climate conditions
• No, they are not perfect

18
Projections
19
Prognosis

• Sea level rise of up to 1 foot
• Reductions in ozone layer
• More intense, less frequent hurricanes
• Ocean ph and oxygen level reduced
• Spread of diseases including malaria, Lyme
  disease, cholera and bubonic plague
• Extinctions of plant an animal species
• Population growth due to less deaths from cold
  weather
• Changes in rainfall patterns

20
What are we doing about it

• Kyoto Protocol
• International environmental treaty to achieve
  stabilization of greenhouse gas concentrations in
  the atmosphere at a level that would prevent
  man-made interference with the climate
• establishes legally binding commitments for the
  reduction of four greenhouse gases (carbon
  dioxide, methane, nitrous oxide, sulphur
  hexafluoride), and two groups of gases
  (hydrofluorocarbons and perfluorocarbons)
  produced by (industrialized) nations,
• general commitments for all member countries.
• Did not impose limitations on developing
  countries (such as China)
• initially adopted for use on 11 December 1997 in
  Kyoto, Japan
• entered into force on 16 February 2005.
• Signed but not ratified by the US

21
Kyoto

• industrialized countries agreed to reduce their
  collective GHG emissions by 5.2 compared to the
  year 1990.
• National limitations range from 8 reductions for
  the European Union and some others to 7 for the
  United States, 6 for Japan, and 0 for Russia.
• The treaty permitted GHG emission increases of 8
  for Australia and 10 for Iceland.

22
US position

• US signed in 1998, but this was symbolic-treaty
  is not binding until ratified.
• Yet the US is the largest per capita emitter of
  carbon dioxide
• Prior to Kyoto, (though with a knowledge of what
  it said) the US Senate passed a resolution that
  stated stated the sense of the Senate was that
  the United States should not be a signatory to
  any protocol that did not include binding targets
  and timetables for developing nations as well as
  industrialized nations or "would result in
  serious harm to the economy of the United
  States
• Main concern is the economic losses associated
  with instituting the caps on carbon emission
• Neither the Clinton nor Bush administration
  submitted the treaty for ratification
• Obama Administrations position is that the
  treaty is about to end, there is no point in
  ratifying it (it has a little less than 3 years
  left)
• States and cities have adopted initiatives to cap
  carbon emissions on their own, based at least in
  part on Kyoto.

23
Reasons for opposition

• Global socialism-a scheme to transfer wealth to
  third world countries and or slow the growth of
  the worlds industrialized democracies
• Doesnt go far enough to curb GHG emissions
• Costs outweigh benefits
• Using a single base year (1990) may result in
  inequities in the caps

24
Next step-beyond Kyoto

• Meeting in Copenhagen in December 2009
• The Copenhagen Accord was drafted by the US,
  China, India, Brazil and South Africa on December
  18, and judged a "meaningful agreement" by the
  United States government.
• It was "taken note of", but not "adopted", in a
  debate of all the participating countries the
  next day, and it was not passed unanimously.
• The document recognized that climate change is
  one of the greatest challenges of the present day
  and that actions should be taken to keep any
  temperature increases to below 2C.
• The document is not legally binding and does not
  contain any legally binding commitments for
  reducing CO2 emissions.
• Many countries and non-governmental organizations
  were opposed to this agreement, but, as of
  January 4, 2010, 138 countries have signed the
  agreement.

25
Cap and Trade

• An environmental policy that caps emissions while
  giving source flexibility in how they comply with
  those caps-uses economic incentives to get
  compliance
• A limit or cap on the amount of a pollutant that
  can be emitted is set. Companies or other groups
  are issued emission permits and are required to
  hold an equivalent number of allowances (or
  credits) which represent the right to emit a
  specific amount. The total amount of allowances
  and credits cannot exceed the cap, limiting total
  emissions to that level. Companies that need to
  increase their emission allowance must buy
  credits from those who pollute less called a
  trade. In effect, the buyer is paying a charge
  for polluting, while the seller is being rewarded
  for having reduced emissions by more than was
  needed. Thus, in theory, those who can reduce
  emissions most cheaply will do so, achieving the
  pollution reduction at the lowest cost to
  society.
• Allowed under Kyoto for nations to sell their
  credits.

26
American Clean Energy and Security Act

• Also known as the Waxman-Markey Act
• Proposes a cap and trade system for Greenhouse
  Gas emissions
• Requires electric utilities to meet 20 of their
  electricity demand through renewable energy
  sources and energy efficiency by 2020.
• Invests in new clean energy technologies and
  energy efficiency, including renewable energy,
  carbon capture and sequestration, electric and
  other advanced technology vehicles, and basic
  scientific research and development.
• Protects consumers from energy price increases.
  According to estimates from the Environmental
  Protection Agency, the reductions in carbon
  pollution required by the legislation will cost
  American families less than a postage stamp per
  day.
• The bill requires a 17-percent emissions
  reduction from 2005 levels by 2020 this would
  reduce United States' emissions by about 80
  percent by 2050. Complementary measures in the
  legislation, such as investments in preventing
  tropical deforestation, will achieve significant
  additional reductions in carbon emissions.
• It includes a renewable electricity standard)
  requiring each electricity provider who supplies
  over 4 million MWh to produce 20 percent of its
  electricity from renewable by 2020. There is a
  provision whereby 5 of this standard can be met
  through energy efficiency savings, as well as an
  additional 3 with certification of the Governor
  of the state in which the provider operates.
• It provides for modernization of the electrical
  grid
• It provides for expanded production of electric
  vehicles
• It mandates significant increases in energy
  efficiency in buildings, home appliances, and
  electricity generation.

27
Climategate

• Also known as the Climate Research Unit e-mail
  controversy
• Internet leak of thousands of emails and other
  documents from the University of East Anglia's
  Climatic Research Unit (CRU).
• emails and documents were obtained through the
  hacking of a server.
• hacker had filtered them using keywords,
  including "Yamal", "tree rings", and "Phil
  Jones", so that these names appear in many of the
  documents

28
Climategate-what was stolen

• more than 1,000 emails, 2,000 documents, as well
  as commented source code, pertaining to climate
  change research covering a period from 1996 until
  2009.
• The vast majority of the emails related to four
  climatologists Phil Jones, the head of the CRU
  Michael E. Mann of Pennsylvania State University
  (PSU), one of the originators of the graph of
  temperature trends dubbed the "hockey stick
  graph Tim Osborn, a climate modeller and Mike
  Hulme, director of the Tyndall Centre for Climate
  Change Research.
• The four were either recipients or senders of all
  but 66 of the 1,073 emails,

29
Climategate-allegations

• Allegations that the hacked emails showed
  evidence that climate scientists manipulated
  data.
• A few other commentators said that the evidence
  supported claims that dissenting scientific
  papers had been suppressed.
• The Wall Street Journal reported the emails
  revealed apparent efforts to ensure the IPCC
  include their own views and exclude others and to
  withhold scientific data.
• Reason reported that the CRU evidently plotted to
  remove journal editors with whom they disagreed
  and suppress the publication of articles that
  they disliked.
• The ICO made a statement that the emails revealed
  that freedom of information requests were 'not
  dealt with as they should have been under the
  legislation' but that they could not prosecute
  due to statue of limitations.
• Academics and climate change researchers said
  that nothing in the emails proved wrongdoing, and
  dismissed the allegations.
• Independent reviews by FactCheck and the
  Associated Press said that the emails did not
  affect evidence that man made global warming is a
  real threat, and said that emails were being
  misrepresented to support unfounded claims of
  scientific misconduct. They also concluded that
  there were disturbing suggestions that scientists
  had avoided sharing scientific data with
  skeptical critics.

30
Climategate-understanding the trick

• Many commentators quoted one email referring to a
  "trick" used in Mann's graph to deal with the
  well-known tree ring divergence problem to "hide
  the decline" that particular proxy showed for
  modern temperatures after 1950, when measured
  temperatures were rising.
• These two phrases were taken out of context by
  climate change skeptics including Senator Jim
  Inhofe and former Governor of Alaska Sarah Palin
  as though they referred to a decline in measured
  global temperatures, even though they were
  written when temperatures were at a record high.
• In their inquiry into allegations of research
  misconduct, Penn State reviewers found the
  so-called 'trick' was nothing more than a
  statistical method used to bring two or more
  different kinds of data sets together in a
  legitimate fashion by a technique that has been
  reviewed by a broad array of peers in the field.
• The Parliament of the United Kingdom select
  committee inquiry concluded that "Trick appears
  to be a colloquialism for a "neat" method of
  handling data," and "hide the decline was a
  shorthand for the practice of discarding data
  known to be erroneous.