Climate and weather variables such as rainfall, temperature, and pressure are indicators for hazards such as tropical cyclones,
floods, and fires. The impact of these events can be due to a single variable being in an extreme state, but more often it
is the result of a combination of variables not all of which are necessarily extreme. Here, the combination of variables or
events that lead to an extreme impact is referred to as a compound event. Any given compound event will depend upon the nature
and number of physical variables, the range of spatial and temporal scales, the strength of dependence between processes,
and the perspective of the stakeholder who defines the impact. Modeling compound events is a large, complex, and interdisciplinary
undertaking. To facilitate this task we propose the use of influence diagrams for defining, mapping, analyzing, modeling,
and communicating the risk of the compound event. Ultimately, a greater appreciation of compound events will lead to further
insight and a changed perspective on how impact risks are associated with climate‐related hazards. WIREs Clim Change 2014, 5:113–128. doi: 10.1002/wcc.252
Conflict of interest: The authors have declared no conflicts of interest for this article.
Schematic of a flood event: (a) a univariate probabilistic system; (b) a multivariate probabilistic system; and (c) process model including decision node.