Robustness and Uncertainties in the New CMIP6 Carbon Cycle Projections in Artic-Boreal Ecosystems
Abstract
Estimating the impacts of climate change on the global carbon cycle relies on projections from Earth System models (ESMs). While ESMs currently project large warming in the high northern latitudes, the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. The new generation of increased complexity ESMs running scenarios for the upcoming Intergovernmental Panel on Climate Change Sixth Assessment Report (IPCC AR6) may improve projections. Here, we benchmark the Coupled Model Intercomparison Project (CMIP) 5 and 6 models (9 CMIP5 members and 12 CMIP6 members) with the International Land Model Benchmarking (ILAMB) tool over the region of NASA's Arctic-Boreal Vulnerability Experiment (ABoVE) in North America. We show that future projected average Net Biome Production (NBP) from CMIP6 models is higher to that from CMIP5 models in the ABoVE domain, despite the model spread being similar and including one another. Although both CMIP groups project the ABoVE region as a carbon sink by 2100, the sink strength in the CMIP6 group increases with CO2 emissions, while both groups indicate a negative inflection in the NBP growing curve by 2070-2080 independently of the Shared Socioeconomic Pathway (SSP) for CMIP6 or Representative Concentration Pathway (RCP) for CMIP5 models.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.B22D..07B