The significance of weather and climate extremes to society: an introduction

Abstract

Events over the past few decades have brought extreme weather and climate events to the fore of societal concerns. Ordinary citizens, individuals in the private sector, and people at the highest levels of government worry about the apparent increase in the frequency of weather and climate events causing extreme, and in some instances catastrophic, impacts. We differentiate between weather events – relatively short-term phenomena associated with, for instance, tropical cyclones (hurricanes and typhoons, for example), severe floods, and the like – and climate events – longer-lived and/or serial phenomena such as drought, season-long heat waves, record wildfire seasons, multiple occurrences of severe storms in a single season or year, etc. The differentiation is related to the distinction between weather, which can be forecast on short timescales of less than 1–2 weeks, and climate, which can be forecast on monthly, seasonal, and annual timescales. The adage “Climate is what you expect and weather is what you get” probably originates from the fact that climate is the statistical average of the weather over a specified time period. Regardless of whether an extreme event is weather- or climate-related, it could have significant and numerous implications for society. This book summarizes our knowledge of different aspects of weather and climate extremes and then focuses on their recent and potential future consequences for different socioeconomic sectors.