Event Date
Speaker: Dr. Daniel L. Swain, Climate Scientist, California Institute for Water Resources, UC ANR
Abstract. There is strong evidence that precipitation extremes will increase in response to planetary warming, even in regions with small or uncertain changes in mean precipitation, due to the exponential (~7%/°C) increase in the water vapor saturation capacity of air dictated by the well-known Clausius-Clapeyron (C-C) relation. Yet beyond extreme precipitation, there is also expanding evidence that processes even indirectly related to spatiotemporal variations in atmospheric moisture, in both saturated and unsaturated environments, scale with warming at exponential rates approximately consistent with C-C (or at a scaling factor thereof). As identified in recent studies, phenomena intensified by increases in specific humidity, evaporative demand/vapor pressure deficit, and/or changes in spatiotemporal gradients related to these quantities include tropical and extratropical cyclones, severe convective weather, jet streaks/atmospheric turbulence, droughts, wildfires, and heatwaves. In this presentation, I will synthesize emerging evidence pointing to the unifying role played by moisture-related effects across a wide range of extreme and societally consequential phenomena in a warming climate. I will also reflect on the practical implications of increasing "whiplash" in the hydroclimate system (and beyond) for California, especially when it comes to planning for and adapting to flood, drought, and wildfire risks.