Ezra's Round Table/Systems Seminar: Brian O'Neill (NCAR) - Does half a degree of global warming matter? Results from the BRACE 1.5 study


Olin Hall 255


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. Bio: Brian O'Neill is an NCAR Senior Scientist and leads the Integrated Assessment Modeling (IAM) group within the Terrestrial Sciences Section. He also leads NCAR's Climate and Human Systems Project, and co-chairs the Societal Dimensions Working Group of NCAR's climate model, the Community Earth System Model (CESM). Brian holds a Ph.D. in Earth Systems Science and an M.S. in Applied Science, both from New York University, and has worked previously on the science staff of the Environmental Defense Fund in New York, and as an Assistant and Associate Professor (Research) at Brown University's Watson Institute for International Studies. During the period 2005-2009, he founded and led the Population and Climate Change Program at the International Institute for Applied Systems Analysis (IIASA) in Austria. His research interests are in the the relationship between future societal development, emissions, and climate change impacts. Research approaches include the development of long-term scenarios, linking of models of the climate system with those of human systems, and the incorporation of uncertainty in analyses of climate-related decisions. Brian is the lead author (along with Landis MacKellar and Wolfgang Lutz) of Population and Climate Change, published by Cambridge University Press. He has also served as a lead author for the Intergovernmental Panel on Climate Change's Fourth and Fifth Assessment Reports in a volume on impacts, adaptation and vulnerability (Working Group II), and for the Millennium Ecosystem Assessment (MA) in a volume on Scenarios. You can follow him on Twitter at @oneill_bc.