The impact of black carbon (BC) aerosols on the global radiation balance is not well constrained. Here twelve global aerosol models are used to show that at least 20% of the present uncertainty in modeled BC direct radiative forcing (RF) is due to diversity in the simulated vertical profile of BC mass. Results are from phases 1 and 2 of the global aerosol model intercomparison project... https://www.nacrack.com/great-pick-Refurbished-Sawgrass-Virtuoso-SG500-Complete-Sublijet-Sublimation-Printer-Kit-flash-buy/