Impact of climate scenarios on vulnerability and coping Impact of climate scenarios on vulnerability...
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Impact of climate scenarios on vulnerability and Impact of climate scenarios on vulnerability and copingcoping
or
“How does the climate modeler fit in the picture”Bruce Hewitson
University of Cape Town, South Africahttp://www.csag.uct.ac.za
Climate change projections and seasonal forecasting
span the time scales for adaptation strategies.
Adaptation is inherently dependant in understanding
and the system, and credible projections to inform /
determine action
End of the month storage in the Western Cape System
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Start Restrictions
end Oct 2000
Impact of climate scenarios on vulnerability and Impact of climate scenarios on vulnerability and copingcoping
or
“How does the climate modeler fit in the picture”Bruce Hewitson
University of Cape Town, South Africahttp://www.csag.uct.ac.za
What future, what adaptation,What coping strategy?
??
Coping strategies and adaptation predicated
on:a) Appropriate projections / forecasts of climate impactb) Quantifiable skill / probability of the forecastc) Effective communication
No usable forecast / projection No effective adaptationNon-effective forecast projection dangerous strategies
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Consequence
Likelihood
RISK
From: ???
Coping strategies and adaptation predicated
on:
a) Appropriate projections / forecasts of climate
impact
Appropriate to impact sector
Relevant variables
Applicable spatial / temporal resolutions
b) Quantifiable skill / probability of the forecast
Error bars / statistical significance
Probability (conditional)
Hit rates / skill scores
c) Effective communication
Language / terminology barriers
Accessibility and visibility
Guidelines / caveats / limitations
A Real-time development
environment: Seasonal
forecasting
Appropriate projections?
CSIRO PPT JFM 2002
NN 600
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NN 4030
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NN 5025
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BN 2550
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NN 5040
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Current projection
s (UM)
10 simulation ensemble mean from simulations at University of Cape Town. Dashed lines enclose regions where the projected
anomaly is statistically different at 90% significance
Adoption examples:
Commercial farmers general view “not useful”Lack of spatial detail (large area average)Inappropriate temporal resolution (3-month average)Difficult to interpret
Subsistence farmers show variable adoptionProblem of sustaining trustDifficult access / communicateDifficult to interpret
Other sectors – variable adoptioneg: Water resource managers dangerous adoption
Naïve acceptance of seasonal forecasts to deep skepticism of climate change projections
Climate change projection: Multi-model mean Δ precipitation
4 of 6 agreement on sign… but which models are correct …
Climate change: the situation worsens
Annual mean change in daily precipitation(2070-2099) – (1970-1999)
HadCM3Baseline perturbation
ECHAM4Baseline perturbation
Nonetheless:
Observed trend coarsely matches GCM projections
Usable for developing adaptation strategies?
Temporalresolution
N a tiveo r rec o rd edre so lu tion
Skill oravailableresolution
Nativeor recordedresolution
Skill or availableresolution
Achieving Spatial requirement
Achieving temporal requirements
Spatialresolu tionPoint
resolution
E nve lope ofuser needs
Downscaling and tailoring: a necessary post-processing
Key issue: delivery of and access to probabilistic products appropriate to user needs.
Appropriate coping strategies for effective adaptation
are, in part, conditional on tailored probabilistic
projections
and
Understanding by climate community of user community needs
Understanding by user community of climate projection limitations
Within-country capacity (local knowledge) to generate tailored products
Effective communication / language
Concluding statements