Cooperative Institute for Research in the Atmosphere

How much will Earth warm? Looking for clues in Earth’s historical energy budget.

Abstract:
The amount of global warming we expect is controversial in the media. A common metric for this is Equilibrium Climate Sensitivity (ECS), which is the eventual warming following doubled atmospheric CO2. Recently published estimates include “maybe things won’t be that bad” (1.7 °C) and “we could probably destroy most of civilisation” (5.3 °C), but the “consensus” value has stayed stubbornly near 3 °C for decades. This talk aims to share some key techniques and to help listeners interpret results that can seem contradictory. In particular, it investigates “energy budget” approaches which are often lauded for being based on observations. It uses a recent study, Lewis & Curry (2018), as a detailed example.

Bio:
Mark works with Graeme Stephens at JPL and mainly retrieves cloud properties with OCO-2. He did his PhD in Reading (UK) before a Caltech postdoc and UCLA JIFRESSE position at JPL. He has also worked on global temperature data, climate sensitivity, carbon budgets and other topics. One paper appeared on John Oliver’s Last Week Tonight and he is a contributing author to the recent IPCC Special Report on Global Warming of 1.5 °C.