GISS Lunch Seminar

Speaker: Anastasia Romanou (NASA GISS)
Topic: Emissions driven simulations with the NASA GISS Earth System Model

Coupling the GISS climate model, modelE, with the prognostic and fully-interactive land and ocean carbon cycle allows us to better describe the Earth System's response to emissions of greenhouse gases and analyze the carbon -- climate feedbacks. In addition, it allows us to estimate the remaining carbon budget for keeping global surface temperature below certain levels, such as 1.5C and 2C, as well as re-evaluate the transient climate sensitivity. In this talk I will describe the timeline and components of model development that went into modelE-ESM and discuss results from past intercomparison studies. I will also outline results from recent simulations where we zero-ed out the CO2 emissions after different global warming levels. In these simulations and at lower forcing levels, fast climate feedbacks are responding to quickly evolving atmospheric CO2 concentrations and are balanced out by carbon uptake from the ocean and the atmosphere. In contrast, at higher forcing levels, the role of the Atlantic Meridional Overturning Circulation becomes critical in setting the climate system's response to zero emissions.