Speaker – Dr. Ivan Mitevski, Princeton University, (website) in 1108 Jordan Hall and via Zoom (hosted by W. Robinson) 

Title – Asymmetric and Non-monotonic Response of the Climate System to Idealized CO2 Forcing

Abstract – Many studies commonly assume linearity when investigating the climate system’s response to CO2 perturbations in Earth System Models. The primary objective of this work is to thoroughly analyze this linearity assumption in a hierarchy of modeling experiments with CO2 concentrations decreasing to 1/8th and increasing up to 8 times the pre-industrial values. We explore various climate system components, including effective climate sensitivity, radiative feedback and forcing, sea ice extent, precipitation, the width of the tropics, Hadley Cell strength, and storm tracks. The findings demonstrate that the response to CO2 perturbations is not linear but rather asymmetric and non-monotonic, with significant implications for scaling responses from specific CO2 perturbation levels and utilizing evidence from past climate states.