The physical climate system
Data needs and priorities
of research community
for climate
Kevin Trenberth
NCAR
Some key events
• 2007 (Oct): Joint WCRP/IGBP /GCOS Workshop: Future Climate Change
Research and Observations: GCOS, WCRP and IGBP Learning from the
Fourth Assessment Report: Sydney, Australia
– http://wcrp.wmo.int/documents/SydneyWorkshopRep_FINAL.pdf
– Trenberth 2008 WMO Bull.
– Doherty et al. 2009 BAMS
• 2008 (May): World Modeling Summit for Climate Prediction: ECMWF,
Reading, UK
• 2009 (March): Joint IPCC/WCRP/IGBP Workshop: New Science
Directions and Activities Relevant to the Fifth Assessment Report of
the Intergovernmental Panel on Climate Change: U. Hawaii, Honolulu,
Hawaii
• 2010 (Sept): WCRP-UNESCO Workshop: Metrics and methodologies of
estimation of extreme climate events; Paris, France
– Zolina et al. 2010 Eos
Global warming is
“unequivocal”:
Adaptation to climate change
•
•
•
•
Assess vulnerability
Devise coping strategies
Determine impacts of possible changes
Plan for future changes
Requires information
Climate Information System
WCRP
Trenberth, 2008
WMO Bull
4
Doherty et al. 2009: BAMS (April issue)
Lessons Learned from IPCC AR4:
Scientific Developments Needed To Understand,
Predict, And Respond To Climate Change
Doherty et al. 2009: BAMS (April issue)
Recommendations:
• 1) Improved process-level understanding,
climate models, observations of climaterelevant parameters and climate monitoring
systems are needed in specific areas.
• 2) Because some degree of climate change is
virtually certain (IPCC 2007), additional efforts
are needed to make climate information more
relevant to decisions concerning impacts,
adaptation and mitigation.
Doherty et al. 2009: Key research needs
1) Improve models
2) Provide reliable climate
forecasts 10-30 year time
frame, with uncertainties
3) Predictions with regional-scale
climate information,
accounting for land surface
processes and biosphere–
atmosphere interactions
4) Ensure the observational
record: incl reprocessing and
reanalysis
Doherty et al. 2009: Key research needs
5) Expand datasets to include
observations of the impacts of
climate change and to account
for autonomous or planned
adaptation.
6) Systematically monitor and
assess vulnerability
7) Harmonize across climate,
impacts, adaptation and
vulnerability: consistent land use,
land cover, emissions; climate
assessments; historic and future
8) Better understand variations in
the hydrological cycle, esp
extremes
Doherty et al. 2009: Key research needs
9) Use physical process
studies, observations,
and syntheses to obtain
a consensus on the
possible nonlinear
responses of ice sheets
to climate change,
including their
influences on rates of
sea level rise.
10) Improve process modeling and understanding of feedbacks in the
carbon cycle across the earth system.
11) Improve understanding of the processes involved in aerosol indirect
forcing
Modeling summit
May 08
Develop strategy to revolutionize prediction of the
climate through the twenty-first century and, in
particular, to help address the threat of global
climate change at the regional level. The outcome
was the recommendation of a
“Climate Prediction Project”
http://wcrp.ipsl.jussieu.fr/Workshops/ModelingSummit/Documents/FinalSummitStat_6_6.pdf
Subsequently, series of articles in BAMS
An Earth System Prediction Initiative
Modeling summit repercussions
Subsequently, series of articles in BAMS:
Shapiro, M., et al., 2007: The socio-economic and environmental benefits of a
revolution in weather, climate and Earth system analysis and prediction. The
Full Picture, Group on Earth Observation, 136–138.
Hurrell, J. W., et al., 2009: A unified modeling approach to climate system
prediction. BAMS, 90, 1819–1832.
Meehl, G., et al., 2009: Decadal prediction: Can it be skillful? BAMS, 90, 1467–
1485.
Shukla, J., et al. 2009: Revolution in climate prediction is both necessary and
possible: A declaration at the World Modelling Summit for Climate Prediction.
BAMS, 90, 175–178.
Shapiro et al., 2010: An earth-system prediction initiative for the Twenty-first
Century. BAMS, 91, 1377-1388.
Nobre, C., et al., 2010: Addressing the complexity of the earth system. BAMS, 91,
1389–1396.
Brunet, G., et al., 2010: Collaboration of the weather and climate communities to
advance subseasonal to seasonal prediction. BAMS, 91, 1397–1406.
Shukla, et al., 2010: Toward a new generation of world climate research and
computing facilities. BAMS, 91, 1407–1412.
From Hollingsworth et al. 2005
Weather Prediction (T1279, ~15 km)
compared with Satellite Observations
ECMWF predictions and Meteosat observations
Martin Miller and Peter Bechtold (ECMWF)
2009 Hawaii Meeting
New Science Directions and Activities Relevant to the
Fifth Assessment Report of the IPCC
Important emerging science topics, (WG I):
• sea level and ice sheet instabilities;
• detection & attribution on the regional level, and of extremes;
• methodology of multi-model ensembles;
• cloud and aerosol processes and associated uncertainties;
• atmospheric chemistry and climate;
• Earth System modeling of climate, including biogeochemistry and land-surface
interactions;
• coverage of the full range of possible futures.
Expert meetings proposed:
•Joint WGI-WGII IPCC Expert Meeting on "The Methodology of Detection and Attribution
on Decreasing Space Scales and Extremes".
•WGI Expert Meeting on "The Methodology Multi-Model Ensembles and Model Metrics"
Other key events in 2009
WCC-3 emphasised the essential roles of observation
and research in providing the basis for climate services
Towards a Global Framework
for Climate Services
OceanObs ’09 developed a common vision for
provision of routine and sustained global information
on the marine environment
WCRP extremes workshop
Workshop on metrics and methodologies of estimation of
extreme climate events: WCRP-UNESCO (GEWEX/CLIVAR/IHP)
• UNESCO, Paris: 27-30 Sept 2010
• Chair: Olga Zolina
• 132 from 32 countries
• Oral, poster, discussion sessions; 3 Breakout Groups
• Community white paper, Eos* and BAMS(?) article
• http://www.extremeworkshop.org/
Goal: To provide much improved observational datasets and
model capabilities on variability and extremes, especially
those that have high impacts on society and the environment;
and develop a climate information system that include
predictions and assessments of future changes in risk from
extremes.
*21 Dec 2010 issue
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Reason for focus on extremes
Mean A: 50°F, s.d. 10°F
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Reason for focus on extremes
Shift in climate:
from A to B
Most of time the
values are the
same (green).
Biggest changes
in extremes:
>200%
Mean A: 50°F, s.d. 10°F
Mean B: 55°F, s.d. 10°F
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Issues for extremes
 High resolution observations are not available (hourly)
 High resolution model data often not saved
 Model results typically not available or archived
 Model definitions are often different from obs
 Model grid box value may not be comparable to mean of grid
box from observations
 Ability and utility of models
 Model extremes are not well simulated.
 Improvements of models (intensity, frequency of precip etc)
 Improvements in resolution
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An Opportunity
A milestone in developing the
WCRP Strategy and an opportunity
to sense the views of the
community
Major research opportunity
Earth system complexity
National Academy of Sciences: Keck Mural
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