Transcript Lecture, IPCC

THE Intergovernmental Panel on
Climate Change (IPCC)
Human activities have already begun to
affect global climate.
Scientists have learned much about
climate and how it responds to human
activities such as emissions of carbon
dioxide and other “greenhouse gases.”
Nevertheless, great uncertainty remains.
Climate change challenges policymakers.
Some argue that it poses a risk of such
serious damage that the lack of full
scientific certainty should not be used as
an excuse to postpone action.
Others regard the risk as manageable and
not worth a major shift in the investment of
financial and human resources.
Somehow, policymakers must sort through
the evidence, weigh the costs and benefits,
evaluate the risks, and decide on action.
Science has a role to play in informing
wise policy.
Because the stakes are so high and the
system so complex, policymakers cannot
rely on on any single expert viewpoint.
Policymakers need an objective source of
the most widely accepted scientific
information about climate change, its
effects, and possible response options.
The IPCC was established in 1988 to
meet this need.
The World Meteorological Organization
(WMO) and the United Nations
Environment Programme (UNEP) jointly
established the IPCC.
It is important to understand that the
IPCC is both governmental and scientific.
Establishing the IPCC
• 1979 First World Climate Conference, WMO.
• 1985 Assessment of the Role of Carbon
Dioxide and of Other Greenhouse Gases in
Climate Variations and Associated Impacts
(UNEP, WMO, ICSU). Conclusion: we are
headed to new climate extremes in the first half
of the 21st C.
Original IPCC Charge
(1988)
1. Science of climate and climatic change
2. Social and economic impacts
3. Possible response strategies
4. International legal instruments
5. International convention on climate
IPCC does not conduct new research.
Its mandate is to assess, on a
comprehensive, objective, open and
transparent basis, the available scientific
information in peer-reviewed literature.
IPCC reports are policy-relevant but not
policy-prescriptive or policy-driven.
The IPCC has produced four major
Assessment Reports (1990, 1995, 2001,
2007).
Each includes Summaries for
Policymakers, written so as to be
comprehensible to the non-specialist.
These are published in all six UN
languages.
The 1990 IPCC First Assessment Report
confirmed the scientific basis for concern
about climate change.
It helped persuade governments to adopt
the UN Framework Convention on
Climate Change, signed at the Earth
Summit in Rio de Janeiro (1992).
The 1995 IPCC Second Assessment
Report contributed crucially to the
negotiations that led to the adoption of
the Kyoto Protocol in 1997.
The Kyoto Protocol, which would restrict
emissions of greenhouse gases, has not
yet come into force, mainly because of
opposition from the United States.
IPCC Summary Statements
•FAR, 1990: The unequivocal detection of the enhanced greenhouse effect is
not likely for a decade or more.
•SAR, 1995: The balance of evidence suggests a discernible human
influence on global climate.
•TAR, 2001: Most of the observed warming over the last 50 years is likely to
have been due to the increase in greenhouse gas concentrations.
•AR4, 2007: Most of the observed increase in globally averaged
temperatures since the mid-20th century is very likely due to the observed
increase in anthropogenic greenhouse gas concentrations.
•AR5, 2011: AGW very, very likely? – No, Aiming for more applied science,
what should we do about climate change?
Increasing
Resolution
FAR 1990
SAR 1995
TAR 2001
AR4 2007
The World
In Global
Climate
Models
AR4 WG2 SPM
•
The impacts of climate change are, with high confidence
(80%), expected to be most significant when and where
they occur in the context of multiple stresses from other
sources such as poverty, unequal access to resources, food
insecurity, and environmental degradation. The intensities
of these interactions vary from place to place and over
time along specific development pathways.
•
Medium confidence (50%) global estimates of the number
of people adversely affected by climate change by 2080:
water scarcity 1-3 billion, hunger 200-600 million, coastal
flooding 2-7 million.
AR4 WG2 fresh water resources
What Students (and Professors) Can Do
Climate change is real and serious. It’s not a hoax.
It won’t go away. It needs thoughtful action.
Everybody can play a role. Be better informed.
Keep this issue prominent. The USA can lead.
Scientific illiteracy helps spread misinformation.
Educate kids (& corporations & politicians too).
Get comfortable with sensitive issues. Population
is a driver. Personal values matter. Think.
www.ipcc.ch