Environmental extremes such as droughts, heatwaves, wildfires, and extreme precipitation place strain on human society including water, energy, food, and supply chain systems. The vulnerability of these systems is a function of the extremes themselves – their magnitudes, frequency, and co-occurrence, etc. However, vulnerability also depends critically on the sensitivities and adaptive capacity of human built and social systems. Multisectoral interactions can either exacerbate the impacts of extreme events in the case of cascading failures, or serve to increase system resiliency by adding redundancy or compensatory actions.

In this presentation, we describe efforts to understand the mechanisms, changing properties, and multi-sectoral implications of extreme events using storyline approach. Storylines are a useful framework for examining how a specific known or hypothetical series of events and actions play out within coupled human-environmental systems. For instance, examining how a historic series of storms led to rain-on-snow streamflow pulses in a particular watershed and how subsequent reservoir operations were able to ameliorate potential flood damages can reveal key system interactions, processes, and phenomena that enhance or reduce flood risk. Once a storyline is established, examining perturbations of the storyline can reveal key sensitivities. What if reservoirs were managed differently? What if the climate were warmer and snowpack was lower but the amount of precipitation in each storm was higher?

The Thermodynamic Global Warming has been refined as a method to examine in detail how present-day or future climate warming affects the characteristics of known weather events. We apply this approach to examine a wide range of extreme event storylines, including storylines related to atmospheric rivers, tropical cyclones, and rain-on-snow runoff. We have also begun an effort to scale up this type of analysis from a handful of historic events to a larger ensemble of events covering a 40-year historic period for the continental US. This approach allows for a more systematic examination of how known extremes respond to changing climate conditions and lends itself to examining human system implications and feedbacks across sectors and scales.