Transcript Climate information for decision making

World Climate Research Programme
Climate Information for Decision Making
Ghassem R. Asrar
Director, WCRP
Outline
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Science Based Decision Making
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World Climate Conference-3: Climate info. for better future
OceanObs09: Ocean observations for society
ICSU visioning: Environment & sustainable development
WCRP Contribution
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Seasonal Predictions
Decadal Predictions
Regional climate predictions
Sea Level variability and change
Seasonal Climate Prediction
• WCRP, through its Working Group on Seasonal to
Interannual Prediction (WGSIP),
– Launched the Climate-system Historical Forecast Project
(CHFP) a multi-model and multi-institutional experimental
framework for sub-seasonal to decadal complete physical
climate system prediction
http://www.clivar.org/organization/wgsip/chfp/chfp.php
• CHFP will provide:
- A baseline assessment of seasonal prediction
capabilities using the best available models of the
climate system and data for initialization
Seasonal Climate Prediction
Challenges
• Quantifying Forecast Uncertainty Due to
Uncertainty in Model Formulation
– Multi-Model Helps, but Ad-Hoc
• Quantifying Forecast Uncertainty Due to
Uncertainty in Observational Estimates
– Initial Condition Problem
• Model Error
– Need for International Coordinated Effort at Improving
Models (Multi-Model is Not an Excuse for Neglecting
Model Improvement)
• Climate System Component Interactions
– Coupled Ocean-Land-Ice-Atmosphere
– External Forcing vs. Natural Variability
• Quantifying the Limit of Predictability
Seasonal Prediction-South Africa
Rainfall forecast
issued in Dec. 2008
by a multi-model
operational
Seasonal
Forecast
by the South
African
Weather Service.
10%
Decadal Climate Experiments
WCRP, through its Working Group on Coupled
Modelling (WGCM)
additional predictions
Initialized in
‘01, ’02, ’03 … ‘09
- has developed the coupledmodel intercomparison project
(CMIP5) that coordinates the
decadal predictability/prediction
experiments
- will provide the foundation for
the simulations to be assessed
as part of the IPCC AR5
prediction with
2010 Pinatubolike eruption
10-year hindcast &
prediction ensembles:
initialized 1960, 1965,
…, 2005
30-year hindcast and
prediction ensembles:
initialized 1960, 1980 &
2005
prescribed
SST timeslices
alternative
initialization
strategies
Decadal Climate Predictability
Observed decadal climate variability in Pacific and Atlantic sectors (left) and
first attempts to make decadal predictions (right)
Regional Climate
The need for climate information at the regional-to-local scale is
one of the central issues within the global change debate.
In 2008 WCRP established a Task Force on Regional
Climate Downscaling (TF-RCD), whose mandate is:
– to summarize the shortcomings, difficulties and scientific basis
of existing downscaling methods to serve as guidance to the
climate change assessment community;
– to develop a framework for evaluation
and intercomparison of regional
downscaling techniques.
Regional Climate
Schematic depiction of the primary uncertainties
in regional climate change projections.
RCD Configuration
(Multiple models)
Systematic Errors
(Model eval./impr.)
AOGCM Configuration
(Multiple AOGCMs)
Uncertainty in
regional climate
projection
Regional cover
(Multiple regions)
Internal variability
(Multiple realizations)
Emis./Conc.
(Multiple
Scenarios)
RCD approach
(Multiple RCD methods)
Regional Climate: Africa - Example
January-FebruaryMarch mean
precipitation for
1998-2008 period.
Regional Climate: Africa - Example
July-August-Septmeber
mean precipitation for
1998-2008 period.
Sea-Level Variability and Change
The main challenge is to address the uncertainties in the
projection of future sea-level changes due to recently
discovered processes in the Greenland and Antarctic
regions.
The joint WCRP/IOC Task Group on Sea-Level Variability
and Change (TF-RCD) was established with the mandate
to:
– Improve further our ability to monitor, explain and predict changes
in global and regional sea level and associated environmental
factors.
– Make available this information for stakeholders and policymakers
Sea-Level Variability and Change:
Regional Impacts
Climate variability
affects
the regional
distribution
of sea-level rise.
CSIRO - Australia
Sea-Level Variability and Change:
Regional Impacts
20th Century – Fort Denison
2.35
Post-1950
Pre-1950
2.30
2.25
Sea Level (m)
• 20th Century sealevel rise has
already caused a
significant increase
in extreme events three-fold increase
post-1950.
• By 2100, 1 in 100
year events are
projected to happen
several times a year!
+0.08m
2.20
x3.1
2.15
2.10
2.05
2.00
0.1
1
10
Return Period (Years)
100
Conclusions
WCRP will continue to:
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Provide Scientific Knowledge on climate variability
and change.
Facilitate research on climate projections and
predictions on centuries, decades and seasons.
Place a major emphasis on regional climate
variability and change with special attention to
extreme events.
Support development and delivery of climate
information for decision makers.
Sponsor training and development of next
generation of regional and global climate experts.