World Climate Research Programme Climate Information for Decision Making Ghassem R. Asrar Director, WCRP.
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World Climate Research Programme Climate Information for Decision Making
Ghassem R. Asrar Director, WCRP
Outline
• – – –
Science Based Decision Making
World Climate Conference-3: Climate info. for better future OceanObs09: Ocean observations for society ICSU visioning: Environment & sustainable development • – – – –
WCRP Contribution
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
coupled model intercomparison project
(CMIP5) that coordinates the decadal predictability/prediction experiments
prediction with 2010 Pinatubo like eruption 10-year hindcast & prediction ensembles: initialized 1960, 1965, …, 2005 30-year hindcast and prediction ensembles: initialized 1960, 1980 & 2005
- will provide the foundation for the simulations to be assessed as part of the IPCC AR5
prescribed SST time slices 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) AOGCM Configuration (Multiple AOGCMs) Systematic Errors (Model eval./impr.) 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-February March 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 policy makers
Climate variability affects the regional distribution of sea-level rise.
Sea-Level Variability and Change:
Regional Impacts CSIRO - Australia
Sea-Level Variability and Change:
Regional Impacts
•
20 th Century sea level 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!
2.35
2.30
2.25
2.20
2.15
2.10
2.05
2.00
0.1
20
th
Century – Fort Denison
Post-1950 Pre-1950 +0.08m
x3.1
1 10 Return Period (Years) 100
Conclusions
WCRP will continue to:
– Provide
Scientific Knowledge
on climate variability and change.
– Facilitate research on
predictions climate projections and
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.