CEES Extra seminar (2/2): Does half a degree of global warming matter? Results from the the BRACE 1.5 study

By Brian O’Neill from the Josef Korbel School of International Studies at the University of Denver, USA


In 2015, 195 countries negotiated the Paris Agreement on climate change, which set long-term goals of limiting global mean warming to well below 2 C and possibly 1.5 C. This event stimulated substantial scientific interest in climate outcomes and impacts on society associated with those levels of warming. Recently, a project coordinated at NCAR was undertaken to produce new global climate model simulations of scenarios that stabilize warming at 1.5 and 2 C, and to investigate their potential impacts. The project, BRACE 1.5 (Benefits of Reduced Anthropogenic Climate changE), asks whether impacts differ substantially between the two climate scenarios, accounting for uncertainty in climate outcomes and in societal conditions. Impact assessment focuses on extreme climate events and the health, agricultural, and building energy sectors. Modeling approaches include the use of three different global, mutli-region integrated assessment models (IAMs), both a process-based and an empirical crop model, and an epidemiological model of heat-related mortality. I discuss the BRACE 1.5 study design and key conclusions, and give a more detailed account of an agricultural impact assessment linking an IAM to the NCAR climate model.


Brian O’Neill is a Professor at the Josef Korbel School of International Studies at the University of Denver. He also serves as Director of Research at the Korbel School’s Pardee Center for International Futures. Brian holds a Ph.D. in Earth Systems Science and an M.S. in Applied Science, both from New York University. His research interests are in human-environment interactions, in particular the relationship between future societal development, greenhouse gas emissions, and climate change impacts. He has led research groups on Integrated Assessment Modeling and on Climate and Human Systems at the US National Center for Atmospheric Research (NCAR), and on Population and Climate Change at the International Institute for Applied Systems
Analysis (IIASA). Brian is a Convening Lead Author for the Intergovernmental Panel on Climate Change’s ongoing Sixth Assessment Report. He is also the lead author of Population and Climate Change, published by Cambridge University Press.

Published Sep. 18, 2018 9:56 AM - Last modified Mar. 8, 2021 10:34 AM