Intergovernmental Panel on Climate Change (IPCC)

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Intergovernmental Panel on Climate Change (IPCC)

• International Scientific Consensus and Climate
  Model Projections

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Outline

• The IPCC as an organization
• What inputs do they use review of some global
  warming evidence
• How do they make models?
• What are the projections?
• Conclusion

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IPCC - Why was it created?
Human activities now occur on a scale that is
starting to interfere with complex natural
systems Climate change poses a serious
challenge to policymakers Policymakers need
an objective source of the most widely accepted
scientific, technical and socio-economic
information available about climate change
The World Meteorological Organization (WMO) and
the UN Environment Programme (UNEP) established
the IPCC in 1988. The Panel does not conduct
new research or monitor climate-related data.
Its mandate is to assess peer-reviewed
literature to ensure a balanced reporting of
viewpoints
All quotes from Introduction to the IPCC -
http//www.ipcc.ch
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IPCC Organization
IPCC Chair
IPCC Bureau
WG I Science
WG II Impacts
WG III Mitigation
Task Force on GHG
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IPCC Reports
First Assessment Report (1990) - Helped lead to
work at Rio de Janeiro Earth Summit (1992) and
UNFCCC Second Assessment Report (1996) -
Contributed to negotiations that lead to Kyoto
Protocol (1997) Third Assessment Report (2001) -
Update concentrating on findings after 1995
looks at regional as well as global effects
Fourth Assessment Report Due in 2007
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IPCC Process
Approximately 1000 experts directly involved
in drafting and revising the reports About 2500
participate in the review process IPCC authors
are nominated by governments and international
organizations, and represent universities, researc
h centers, business and environmental groups
from 120 countries
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IPCC Process
...(T)eams of lead authors are assembled Every
chapter team must represent a range of
prevailing scientific-technical viewpoints and
expertise, and ensure appropriate representation
of experts from developing and developed
countries
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Temperature Change - Century
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Temperature Change - Millenium
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Energy Balance
Earths Energy Imbalance Confirmation and
Implications James Hansen, et al. Science 3 June
2005 308 1431-1435 Current imbalance of
0.850.15 W/m2
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Model Forcings
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Natural or anthropogenic?
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Model scenario indicators
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Model projections
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IPCC model scenarios
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IPCC Projections
66-90
90-99
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Carbon Budget
Watson, IPCC
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Natural CO2 changes
2100
2100
Petit et al, Nature v.399 (6735), pp. 429-436.
(1999)
today
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CO2 Concentrations
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Methane Fluctuations
1500 ppbv (today)
Petit et al, Nature v.399 (6735), pp. 429-436.
(1999)
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Probability distributions
Interpretation of High Projections for
Global-Mean Warming T.M.L. Wigley and S.C.B.
Raper 20 JULY 2001 VOL 293 SCIENCE
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Stop burning fossil fuels?
The Climate Change Commitment T. M. L. Wigley
18 MARCH 2005 VOL 307 SCIENCE
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Keep burning at same rate?
The Climate Change Commitment T. M. L. Wigley
18 MARCH 2005 VOL 307 SCIENCE
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Questions

• Is the current evidence convincing (especially
  for non-scientists)?
• Are models scenarios convincing (as a way to
  project to the future)?