Global warming-the debate

1
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

2
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)

3
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.

4
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

5
Projections
6
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

7
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

8
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.

9
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.

10
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