The Complex Dyanmics of the Climate System: Constraints on our Knowledge, Policy Implications and the Necessity of Systems Thinking

Abstract

This chapter describes the contribution of complexity science to understanding of the climate system and the unique challenges its complex properties pose to climate predictions and policy analysis. First, it presents a brief exploration of the Earth's climate system through the lens of complexity science. Then, it introduces the data sources and modeling strategies that climate science uses to understand past behavior, to fingerprint causes of current climate changes, and to project future climate. The complex dynamics of the climate system constrain ability to gain knowledge about the climate system and add uncertainty to predictions of the impacts of human-induced climate change. It also investigates six case studies that illustrate the importance and development of key complexity themes in climate science: glacial-interglacial cycles, thermohaline ocean circulation, ice sheets, vegetation cover changes, extinction, and overshoot scenarios. In addition, it investigates the implications of the complexity of the Earth system for climate policy analysis. Assessments of the impacts of climate change are often disciplinary-based and not sufficiently integrative across important disciplinary subcomponents, producing misleading results that have potentially dangerous environmental consequences. The current framework of cost-benefit optimization is particularly flawed. Further, it describes how one should restructure climate policy analysis as an integrated assessment process, combining data and relationships from the physical, biological and social sciences, that includes robust assessments of potential risks within a vulnerability framework.