Speaker: Anastasia Romanou
NASA Goddard Institute for Space Studies
And Dept of Applied Phys. and Applied Math., Columbia University
Title: Using Earth System Models to explore climate response to curbing emissions
Abstract: Earth system models (ESMs) integrate the interactions of atmosphere, ocean, land and ice with the biosphere to estimate the state of regional and global climate under a wide variety of conditions. Because ESMs simulate interactively sources and sinks of carbon, in addition to sources and sinks of heat, they are particularly useful for analyzing the response of the climate system to changing greenhouse gas emissions, exploring the possibility of temperature stabilization as well as the degree to which changes in the Earth system are reversible under negative emissions. An important observation-based metric that is estimated from ESMs is the transient climate response to emissions (TCRE). TCRE represents the level of the realized warming above a fixed preindustrial reference to the cumulative amount of carbon released into the atmosphere from human activities such as fossil fuel use and land-cover-land-use change but also the marine and terrestrial carbon sinks. In this talk, I will highlight a variety of experiments where we use the NASA GISS modelE-ESM to estimate remaining carbon budgets, i.e. how much carbon we can still emit before a given temperature threshold is exceeded, as well as the system’s response to scenarios of reducing emissions, such as zero emissions scenarios or scenarios of carbon dioxide removal (CDR). Using the linearized energy balance model, we can estimate the relative contribution of ocean heat uptake, land and ocean carbon uptake to the climate system’s response to changing emissions. We find that that delayed mitigation beyond 2oC might not achieve the desired global temperature stabilization over the decadal to centennial timescales and might not avoid tipping points such as a possible collapse of the Atlantic Meridional Overturning Circulation (AMOC).
Bio: Dr. Anastasia Romanou is a Research Physical Scientist at NASA Goddard Institute for Space Studies, in New York and adjunct faculty at Dept of Applied Phys. and Applied Math., Columbia University. She got her PhD at Florida State University in Geophysical Fluid Dynamics studying turbulent boundary layers and holds a bachelor’s degree from the Physics Dept. in the University of Athens, Greece. She did postdoctoral research at University of Miami, Los Alamos National Laboratory and the Courant Institute of Mathematical Sciences, at NYU. Currently, she is part of the modelE-ESM development team and focuses on ocean physical and biogeochemical interactions and feedbacks with the climate system.