Post on 20-Jan-2016
World Climate Research ProgrammeWorld Climate Research Programme
Climate Information for Decision MakingClimate Information for Decision Making
Ghassem R. AsrarDirector, WCRP
OutlineOutline
• 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 PredictionSeasonal 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 PredictionSeasonal Climate PredictionChallengesChallenges
• 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 AfricaSeasonal Prediction-South Africa
10%
Rainfall forecastissued in Dec. 2008by a multi-model operational
Seasonal Forecastby the South African
Weather Service.
Decadal Climate ExperimentsDecadal Climate Experiments
additional predictions Initialized in
‘01, ’02, ’03 … ‘09
100-yr
“control” & 1%
CO2
prediction with 2010 Pinatubo-
like eruption
alternative initialization strategies
atmos. chem
istry
&/or aerosols &/or
regional air quality prescribed SST time-
slices
exte
nd
ense
mble
s
from
O(3
) to
O(10)
mem
bers
hind
cast
s with
out
volca
noes
30-year hindcast and prediction ensembles: initialized 1960, 1980 &
2005
10-year hindcast & prediction ensembles: initialized 1960, 1965,
…, 2005
WCRP, through its Working Group on Coupled Modelling (WGCM)
- has developed the coupled-model 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
Decadal Climate PredictabilityDecadal Climate Predictability
Observed decadal climate variability in Pacific and Atlantic sectors (left) and first attempts to make decadal predictions (right)
Regional ClimateRegional 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 ClimateRegional Climate
Uncertainty inUncertainty inregional climateregional climate
projectionprojection
Emis./Conc.Emis./Conc.(Multiple(Multiple
Scenarios)Scenarios)
AOGCM ConfigurationAOGCM Configuration(Multiple AOGCMs)(Multiple AOGCMs)
Internal variabilityInternal variability(Multiple realizations)(Multiple realizations)
RCD ConfigurationRCD Configuration(Multiple models)(Multiple models)
RCD approachRCD approach(Multiple RCD methods)(Multiple RCD methods)
Regional coverRegional cover(Multiple regions)(Multiple regions)
Schematic depiction of the primary uncertainties Schematic depiction of the primary uncertainties in regional climate change projections.in regional climate change projections.
Systematic ErrorsSystematic Errors(Model eval./impr.)(Model eval./impr.)
Regional Climate: Regional Climate: Africa - ExampleAfrica - Example
January-February-March mean precipitation for 1998-2008 period.
Regional Climate:Regional Climate: Africa - ExampleAfrica - Example
July-August-Septmeber mean precipitation for 1998-2008 period.
Sea-Level Variability and ChangeSea-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.
CSIRO - Australia
Sea-Level Variability and Change:Sea-Level Variability and Change: Regional ImpactsRegional Impacts
Sea-Level Variability and Change:Sea-Level Variability and Change:
Regional ImpactsRegional Impacts
2.35
2.30
2.00
2.25
2.20
2.05
2.15
2.10
Sea
Lev
el (
m)
Return Period (Years)
0.1 101 100
+0.08m
x3.1
Post-1950
Pre-1950
20th Century – Fort Denison• 20th 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!
ConclusionsConclusionsWCRP will continue to:
– 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.