Options for Improving Climate Modeling to Assist Water Utility ...

Water Utility Climate Alliance White Paper
Options for Improving Climate Modeling to Assist Water Utility Planning for Climate Change
Contents
List of Figures............................................................................................................................ vii
List of Tables ...............................................................................................................................ix
List of Acronyms and Abbreviations ........................................................................................xi
Preface.........................................................................................................................................xv
Executive Summary ................................................................................................................. S-1
Chapter 1 Introduction...................................................................................................... 1-1
1.1 What Water Utilities Want from Climate Change Models: Key Objectives ..... 1-3
Chapter 2
Perspectives from Water Utilities: Current Uses of Climate Models
and Desired Output Scales .............................................................................. 2-1
2.1 What Methods Have Water Utilities Used to Analyze Climate Change
Impacts on Water Resources? ............................................................................ 2-1
2.1.1 Denver Water ......................................................................................... 2-1
2.1.2 The New York City Department of Environmental Protection ............. 2-3
2.1.3 Portland Water Bureau........................................................................... 2-4
2.1.4 Seattle Public Utilities ........................................................................... 2-5
2.1.5 Summary of analysis by utilities ............................................................ 2-7
2.2 Analysis of Desired Spatial and Temporal Resolution Based on Utility
Planning Models ................................................................................................ 2-7
Chapter 3 The Science of Climate Modeling ................................................................... 3-1
3.1 Global Climate Models...................................................................................... 3-1
3.1.1 What is a GCM? .................................................................................... 3-1
3.1.2 How are climate projections generated, and how do they differ
from predictions? ................................................................................... 3-5
3.1.3 What are the plans for CMIP5? ............................................................. 3-7
3.1.4 How are GCMs managed? ..................................................................... 3-9
3.1.5 How are climate projection intercomparison runs decided?................ 3-10
3.1.6 How are the models evaluated for accuracy?....................................... 3-10
3.1.7 Which processes are represented in the models? ................................. 3-11
3.1.8 How well do the models reproduce past climate, variability,
and extremes? ...................................................................................... 3-14