New Paper “Decision Scaling: Linking Bottom-Up Vulnerability Analysis With Climate Projections In The Water Sector” By Brown Et Al 2012

Pielke Sr Research Group: News and Commentary

I was alerted to a new paper by Faisal Hossain that has adopted part of  the bottom-up perspective with respect that we hae proposed in our article

Pielke, R. A., Sr., R. Wilby,  D. Niyogi, F. Hossain, K. Dairuku,J. Adegoke, G. Kallos, T. Seastedt, and K. Suding (2012), Dealing with complexity and extreme events using a bottom-up, resource-based vulnerability perspective, in Extreme Events and Natural Hazards: The Complexity Perspective, Geophys. Monogr. Ser., vol. 196, edited by A. S. Sharma et al. 345–359, AGU, Washington, D. C., doi:10.1029/2011GM001086. [the article can also be obtained from here]

The new paper is

Brown, C., Y. Ghile, M. Laverty, and K. Li (2012), Decision scaling: Linking bottom-up vulnerability analysis with climate projections in the water sector, Water Resour. Res., 48, W09537, doi:10.1029/2011WR011212.

The abstract reads [highlight added]

There are few methodologies for the use of climate change projections in decision making or risk assessment processes. In this paper we present an approach for climate risk assessment that links bottom-up vulnerability assessment with multiple sources of climate information. The three step process begins with modeling of the decision and identification of thresholds. Through stochastic analysis and the creation of a climate response function, climate states associated with risk are specified. Climate information such as available from multi-GCM, multi run ensembles, is tailored to estimate probabilities associated with these climate states. The process is designed to maximize the utility of climate information in the decision process and to allow the use of many climate projections to produce best estimates of future climate risks. It couples the benefits of stochastic assessment of risks with the potential insight from climate projections. The method is an attempt to make the best use of uncertain but potentially useful climate information. An example application to an urban water supply system is presented to illustrate the process.

The article contains the statement with respect to the top-down global climate model predictions that

A problem with this approach is that GCM projections are relatively poor scenario generators.

I agree, and would add that they have provided NO demonstration of skillful regional and local predictions of changes in climate statistics from that in the historical and paleorecord.

The authors also write

“A novel aspect of the approach is that it uses decision analysis as a framework for characterizing the climate future, and consequently, climate projections, in terms of their position relative to decision thresholds. In doing so, it uses stochastic analysis for risk identification and uses GCM projections for risk estimation, assigning probabilities to hazards, thus linking the two methods.”

“Appropriately tailored climate information, including GCM projections and stochastically generated conditions from historical and paleodata, and the application of expert judgment, may provide informative answers to this question when approached in the manner described here.”

While the paper still seems to accept the robustness of the global climate model predictions, it does recognize that there are other approaches to accept climate risk.

The article, unfortunately, does not consider other environmental and social risks, relative to climate risks. In the Pielke et al 2012 paper we wrote

“We discuss the adoption of a bottom-up, resource–based vulnerability approach in evaluating the effect of climate and other environmental and societal threats to societally critical resources.This vulnerability concept requires the determination of the major threats to local and regional water, food, energy, human health, and ecosystem function resources from extreme events including climate, but also from other social and environmental issues. After these threats are identified for each resource, then the relative risks can be compared with other risks in order to adopt optimal preferred mitigation/adaptation strategies.

This is a more inclusive way of assessing risks, including from climate variability and climate change than using the outcome vulnerability approach adopted by the IPCC. A contextual vulnerability assessment, using the bottom-up, resource-based framework is a more inclusive approach for policymakers to adopt effective mitigation and adaptation methodologies to deal with the complexity of the spectrum of social and environmental extreme events that will occur in the coming decades, as the range of threats are assessed, beyond just the focus on CO2 and a few other greenhouse gases as emphasized in the IPCC assessments.”

Nonetheless, it is refreshing to see the much-needed start of a movement away from the top-down IPCC approach of assessing risks to key resources, which, as we have shown in our papers and in my weblog posts, is a fundamentally flawed approach.

I have sent the first author a copy of our 2012 paper and hope they will move to the complete adoption of the bottom-up, resource-based perspective.

source of image

Climate Science: Roger Pielke Sr