CESM2 - Highly Optimistic Projections Ensemble (HOPE)

The HOPE project is a collaborative activity between the Community Earth System Model (CESM) Land Model and Biogeochemistry Working Groups (LMWG and BGCWG). The HOPE project goes beyond previous CMIP6 CESM2 simulations performed at the National Center for Atmospheric Research (NCAR), as the model is configured to be Emission driven with a fully interactive carbon cycle as well as having interactive fire and biogenic volatile organic compounds (BVOCs) providing precursors to aerosols in the model. The project explores five member ensembles of the CESM 2.1.5 model with the Shared Socioeconomic Pathway 1 and radiative forcing of 1.9 W/m2 in the year 2100 (SSP1-1.9), compared with the same simulations under the higher emission scenarios of the Shared Socioeconomic Pathway 2 with a radiative forcing of 4.5 W/m2 (SSP2-4.5), and the Shared Socioeconomic Pathway 3 with a radiative forcing of 7.0 W/m2 (SSP3-7.0). The SSP1-1.9 scenario is the most highly optimistic climate future found in the CMIP6 ScenarioMIP project which has not previously been simulated in CESM.