Synthesizing Observed Impacts of Extreme Weather Events Across Systems

wealthy and poor populations. In this chapter we will refer to such an assessment as a synthesis. This chapter is concerned with possibilities and challenges of syntheses that might inform the UNFCCC ABSTRACT This chapter discusses synthesis assessments of the impacts of extreme weather across multiple types of impacts. It considers existing global synthesis efforts rather than developing a new analysis based on other chapters in this book. It includes discussion of the motivation for such assessments, challenges in performing syntheses related to extremes, and possible methods for assembling a synthesis. The focus is on the detection and attribution of impacts during the past half-century, but implications for predicting and, ultimately, documenting future changes in risk are also discussed. The only synthesis assessment of past impacts related to extreme weather is reviewed, noting that its shortcomings can be overcome only through further developments in a number of areas, including monitoring and process understanding.