Demystifying Climate Models

Abstract

Human-caused climate change is perhaps the defining environmental issue of the early twenty-first century. We observe the earth’s climate in the present, but observations of future climate are not available yet. So in order to predict the future, we rely on simulation models to predict future climate. This book is designed to be a guide to climate simulation and prediction for the non-specialist and an entry point for understanding uncertainties in climate models. The goal is not to be simply a popular guide to climate modeling and prediction, but to help those using climate models to understand the results. This book provides background on the earth’s climate system and how it might change, a detailed qualitative analysis of how climate models are constructed, and a discussion of model results and the uncertainty inherent in those results. Throughout the text, terms in bold will be referenced in the glossary. References are provided as footnotes in each chapter. Who uses climate models? Climate model users are practitioners in many fields who desire to incorporate information about climate and climate change into planning and management decisions. Users may be scientists and engineers in fields such as ecosystems or water resources. These scientists are familiar with models and the roles of models in natural science. In other cases, the practitioners are engineers, urban planners, epidemiologists, or architects. Though not necessarily familiar with models of natural science, experts in these fields use quantitative information for decision-making. These experts are potential users of climate models. We hope in the end that by understanding climate models and their uncertainties, the reader will understand how climate models are constructed to represent the earth’s climate system. The book is intended to help the reader become a more competent interpreter or translator of climate model output.