No methodology has yet been generally accepted for assessing the significance of climate risks relative to all other risks to water resources projects.
The goal of this book, "The Decision Tree Framework," is to outline a pragmatic process for risk assessment of water resources projects that can serve as a decision support tool to assist project planning under uncertainty. The approach adopted here is a robustness-based, bottom-up alternative to previous top-down approaches to climate risk assessment, the quality of which has been contingent on the accuracy of future climate projections derived from general circulation models (GCMs).
The Decision Tree's approach to risk assessment aims at a thorough understanding a project’s vulnerabilities to climate change, in the context of other non-climate uncertainties (e.g., economic, environmental, demographic, political). It helps to identify projects that perform well across a wide range of potential future climate conditions, as opposed to seeking solutions that are optimal in expected conditions.
The Decision Tree process was designed with the needs of resource-limited program managers and project developers in mind. The procedure consists of four successive phases:
- Phase 1: Project Screening
- Phase 2: Initial Analysis
- Phase 3: Climate Stress Test;
- 'Phase 4: Climate Risk Management.
At the conclusion of the process, the project planner will be empowered to confidently communicate the method by which the vulnerabilities of the project have been assessed, and how the adjustments that were made (if any were necessary) improved the project’s feasibility and profitability. The result is different categories of projects that undergo different types of analysis with effort that is proportionate to the need.