CEE Seminar: Confirming a Critical Foundation of Global Warming - Direct Observational Evidence from Space of the Impact of CO2 Growth on Infrared Spectra

Abstract: A direct measurement from space of the impact of increased atmospheric CO2 on the spectra of Earth's infrared radiation is presented. The goal of this study is to experimentally confirm that the direct effects of CO2 growth on the Earth’s outgoing infrared spectra follow theoretical estimates, by developing a methodology that allows for a direct and more precise comparison between theory and observations. In this methodology, a search is performed to find selected ensembles of observed atmospheric vertical profiles of temperature and water vapor that are as similar as possible. By analysing the spectral radiances measured from space by the Atmospheric Infrared Sounder, corresponding to the selected ensembles of profiles, the effects of increased CO2 on the spectra can be isolated from the temperature and water vapor effects. The results illustrate the impact of the increase of CO2 on the infrared spectra and compare well with theoretical estimates. This is the first time that the spectral signature of the increase of CO2 (isolated from temperature and water vapor changes) has been directly observed from space. As such, these results confirm a critical foundation of the science of global warming.

Bio: João Teixeira is the co-director of the Center for Climate Sciences, the Lead of the Radiation Sciences Group and the Atmospheric Infrared Sounder Science Team Leader at NASA’s Jet Propulsion Laboratory (JPL), California Institute of Technology (Caltech). He is also a visiting associate and lecturer at Caltech and a visiting scientist at UCLA. Prior to JPL, he was at the European Center for Medium-range Weather Forecasts and the U.S. Naval Research Laboratory. He uses theory, models and observations to better monitor, understand and predict the physics of the climate system, focusing on turbulence, clouds and climate. Together with Pier Siebesma, he is the original developer of the Eddy-Diffusivity/Mass-Flux (EDMF) unified approach for turbulence and convection that has been implemented operationally in several atmospheric models used for weather and climate prediction. He has served on a variety of national and international committees and currently plays a key role in leading the development of a new NASA mission to observe the planetary boundary layer from space. He has received the NASA Exceptional Achievement Medal and the NASA Outstanding Public Leadership Medal.