Communicating Climate Change Science (Intergovernmental Panel on Climate Change)

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Communicating Climate Change Science(Intergovernm
ental Panel on Climate Change)
Tim Killeen Director, National Center for
Atmospheric Research President, American
Geophysical Union AGI Geoscience Leadership
Forum 30 April 2007
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National Center for Atmospheric Research

• National Science Foundation funded Center, gt1,000
  Scientists and engineers, 48 year history
• Earth System Sciences Computational and
  Observational Science and facilities for Weather,
  Climate, Chemistry, Space Weather,
  Society-Environment Interactions

American Geophysical Union

• Worlds largest Geophysics Society (gt49,900
  members, 20 students, 130 countries)
• Interdisciplinary science for the atmospheric and
  ocean sciences solid-Earth sciences hydrologic
  sciences and space science

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AGU Mission AGU Council, 2005EOS, Vol. 86, No.
23, 219, 2005

• AGU is a worldwide scientific community that
  advances, through unselfish cooperation in
  research, the understanding of Earth and space
  for the benefit of humanity.
• AGU is advancing the Earth and space sciences by
  catalyzing and supporting the efforts of
  individual scientists within and outside the
  membership. We are organizing and disseminating
  information for the scientific community. As a
  learned society we meet our obligation to serve
  the public good by fostering quality in the Earth
  and space sciences and bringing the results of
  research to the public. These efforts are
  yielding greater numbers and diversity of
  well-educated students and young professionals in
  the Earth and space sciences, and are increasing
  the public's understanding and appreciation of
  the value of science and support for it.

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The Two Cultures

• What scientists say
• 90 of scientists think few members of the press
  understand the nature of science and technology
• 66 said most press members have no idea how to
  interpret scientific results
• 69 said most reporters have no understanding of
  scientific method
• More than 50 have had a bad experience

• What journalists say
• 85 of reporters think scientists are somewhat or
  not at all accessible
• 62 think scientists are so intellectual or
  immersed in their jargon that they cannot
  communicate

Results from survey, used in NCAR media training,
2007
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NCAR ScientistsInvolved in IPCCWorking Group I
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AGUs Climate Statements

• 1998 (reaffirmed in 2002)
• AGU believes that the present level of scientific
  uncertainty does not justify inaction in the
  mitigation of human-induced climate change and/or
  the adaptation to it.
• 2003The global climate is changing and human
  activities are contributing to that change.
• 2007
• Planned

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The Challenge of Simulating the Global Earth
System
Atmosphere
Hydrosphere
Cryosphere
Biosphere
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The Earth System
From Andi Andreae
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(No Transcript)
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CCSM Working Groups
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Need for High Resolution
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Science Driven Demand for Supercomputing
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Modern Climate Model Simulations

• NCARs Bluesky Supercomputer
• 1600 Processors
• Peak speed 8.3 Teraflops

• Characteristics of NCAR Model
• 1 quadrillion operations/simulated year
• UN IPCC 10,800 years simulated
• Rate of simulation 3.5 sim. years/day
• Output 10 GB/simulated year
• Data volume for IPCC 110 TB (200,000 Data
  CDs)
• Development effort 1 person-century

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Community Climate System Model and the IPCC
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Intergovernmental Panel on Climate Change (IPCC)
Fourth Assessment Report

• NCAR Community Climate System Model (CCSM-3).
• Open Source
• 8-member ensembles
• 11,000 model years simulated
• T85 - high resolution

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IPCC 2007 Summary for Policymakers

• Higher confidence in projected patterns of
  warming and regional-scale features, continuing
  currently observed trends
• warming greatest over land and at most high
  northern latitudes (least over Southern Ocean and
  parts of NA ocean)
• snow cover will contract
• widespread increases in thaw depth over most
  permafrost regions
• sea ice will shrink in both Arctic and Antarctic,
  in some projections late summer sea ice
  disappears in the Arctic by latter part of 21st
  century
• very likely that hot extremes, heat waves, and
  heavy precipitation events will continue to
  become more frequent
• likely that typhoons and hurricanes will become
  more intense
• extra-tropical storm tracks will move poleward
• precipitation at high latitude very likely to
  increase, while decreases are likely in most
  subtropical land regions
• Very likely that meridional overturning
  circulation of the Atlantic Ocean will slow down
  during the 21st century. Average reduction by
  2100 is 25 (0-50). Very abrupt transition is
  very unlikely in 21st century.
• Anthropogenic warming and sea level rise will
  continue for centuries due to the timescales
  associated with climate processes and feedbacks,
  even if greenhouse gas concentrations were
  stabilized

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So, how best to communicate?(some results)
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Tony Blair

• What is now plain is that the emission of
  greenhouse gasesis causing global warming at a
  rate that began as significant, and is simply
  unsustainable in the long-term. And by long-term
  I do not mean centuries ahead, I mean within the
  lifetime of my children certainly and possibly
  within my own. And by unsustainable I do not mean
  a phenomenon causing problems of adjustment. I
  mean a challenge so far-reaching in its impact
  and irreversible in its destructive power, that
  it alters radically human existence.

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A lifetime of climate change
NASA
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Global mean temperatures are rising faster with
time
Period Rate Years ?/decade
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Time Scales in the Climate System
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Probabilistic Outcomes
Wigley
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Ann avg 1980-1999 ice thickness
Simulated late 20th century ice conditions
IPCC AR4 DashMarch extent WhiteObs Extent
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Abrupt Ice Retreat Could Produce Ice-Free Arctic
Summers by 2040

• Recent retreat of Arctic sea ice is likely to
  accelerate so rapidly that Arctic Ocean devoid of
  ice during summertime as early as 2040
• Study by Marika Holland and teams from University
  of Washington, and McGill University
• Several reasons for the abrupt Ice loss in a
  gradually warming world.
• Positive Feedback
• As the ice retreats, the ocean transports more
  heat to the Arctic and the open water absorbs
  more sunlight, further accelerating the rate of
  warming and leading to the loss of more ice

Ice Retreat Animation
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Projections of Degradation of Near-Surface
Permafrost
Lawrence and Slater, 2005
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Future changes in frost days from the climate
model show greatest decreases in the western and
southwestern U.S., similar to late 20th century
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Changes in snowpacks/ timing of runoff have
occurred will continue
Observed streamflow timing changes (Center of
mass)
Trends are projected to continue through the 21st
Century with increased winter flood risks
lower summer low-flows in many rivers.
Observed 1948-2002
Large circles indicate sites with trends that
differ significantly from zero at a 90
confidence level (Courtesy of Michael
Dettinger USGS, based on Stewart et al. 2005.)
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Ozone Recovery in the 21st Century
Global Average Total Ozone Column
Ozone (Dobson Units)
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National Security and the Threat of Climate Change

• CNA Corporation, 2007
• National security consequences of climate change
  should be fully integrated into national security
  and national defense strategies
• US should commit to a stronger national and
  international role to help stabilize climate
  changes at levels that will avoid significant
  disruption to global security and stability
• U.S. should commit to global partnerships that
  help less developed nations build the capacity
  and resiliency to better manage climate impacts
• DoD should enhance its operational capability
  through energy efficiency
• DoD should conduct an assessment of the impact on
  U.S. military installations world-wide of rising
  sea levels, extreme weather events, and other
  possible climate change impacts over the next 30
  to 40 years.

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National Security and the Threat of Climate Change

• CNA Corporation, 2007
• There is no known natural forcing that can
  account for the severity of the recent warming.
  For example, while claims are made that the
  variation in the intensity of the Sun is
  responsible, the solar radiations effect on the
  climate is estimated to be less than 5 as strong
  as that of human-induced greenhouse gases.
• Precipitation patterns have changed
• Extreme weather events are more frequent and Ice
  and snow cover is disappearing
• Oceans are warming
• Sea levels are rising
• Ocean salinity has changed

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(No Transcript)
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Lessons Learned
Large efforts to develop comprehensive scientific
viewpoints can be extremely significant in
influencing public debate The key question
what do we do about climate change? is much
less well addressed than the scientific case for
climate change itself. Issues of timescales,
rates, greenhouse effect, and uncertainty all
need careful treatment. The propensity of the
media to describe arguments continues to lead to
public confusion. Responsibly informing societal
decision makers with the best available science
is tough for individuals trained as
scientists. Bottom line The IPCC Fourth
Assessment Report is currently the most
comprehensive assessment of the scientific
literature on climate change, and effectively and
accurately communicates to policymakers and the
public the state of human knowledge on this
topic.