Translating Climate Uncertainty to Risk: A Process-based Statistical Perspective

Abstract:  

Extreme weather and climate events often show clustering or synchronicity in space and time, affecting the likelihood of subsequent events. These events interact concurrently or at a time lag, resulting in compound events with a significant socio-economic impact than the sum of their parts. A major challenge to quantifying the rarity of such events is the complex dependence between drivers, and a cascade of uncertainty across modeling components, impeding credible future projections. Causal attributions of these events have proved difficult, partly owing to the competing or collective influences of global warming and regional changes such as irrigation, industrialization, and land use change, including deforestation or urbanization. Furthermore, the nature of the uncertainties is complex; it could range from incomplete understanding of the physics to intrinsic variability of the hydroclimate system and variability in greenhouse gas emissions. The trends, including nonstationarity and uncertainty, as well as deep uncertainty from extreme sensitivity to initial conditions and chaos, if any, must be characterized and translated to decision-relevant metrics for resilient planning. This talk elucidates the understanding of drivers and predictability of compound extremes and discusses the next steps and outstanding challenges. Case studies will cover multivariate characterizations of catchment-scale hydrological droughts at local to global scales to developing insights on scarcer and warmer water and associated risk to power productions in the United States based on observations and climate models; attributing seemingly contrasting compound hazard chains, heatwaves– tropical cyclones–extreme precipitation in South Asia; mapping compound hazard potentials of fluvial and coastal floods in Europe, based on observations and regional climate model simulations.

Bio:
Dr. Poulomi Ganguli is an Assistant Professor at the Indian Institute of Technology Kharagpur and currently a Fulbright-Kalam Climate scholar at the Department of Civil and Environmental Engineering, Princeton University. Dr. Ganguli received a Ph.D. in Civil Engineering from the Indian Institute of Technology Bombay, India. She has a wealth of research experience from around the world with academic and research appointments in India, the United States, Canada, and Germany. She received the Alexander von Humboldt, early career research fellowship for her research at GFZ German Research Centre for Geosciences, Potsdam. Her research interests include hydroclimatology and
hydrologic extremes, climate model evaluation, climate change impact assessment in surface and subsurface hydrology, and climate-water-energy nexus.