Talk Abstract:
While much attention has been given to understanding how anthropogenic greenhouse gas emissions influence the mean state of the climate system, far less scrutiny has been paid to how they may modulate naturally occurring modes of climate variability. In this talk, I will present a new analysis of projected changes in the patterns and amplitudes of atmospheric circulation variability over the North Pacific and North America based on a novel set of global climate model simulations. As climate change ensues, these naturally-occurring modes of variability amplify and expand their region of influence, with exacerbating impacts on precipitation. These changes are driven partly by teleconnections from amplified ENSO activity in the tropical Pacific, and partly by dynamical processes intrinsic to the extra-tropical atmosphere. The anticipated changes in both mean climate and natural climate variability present fundamental societal challenges to future water resource planning, flood control, and drought mitigation.