For aerosols in a model that includes aerosol indirect effects, the cloud responses could arguably be put in either category. (giss.nasa.gov)
Several observational studies (see Chapter 5) support the existence of the first aerosol indirect effect on low - level clouds and a negative sign for the associated radiative forcing, but these studies do not give indications on what a (negative) upper bound of the forcing would be. (ipcc.ch)
Additional runs for 2000 with 1850 climate and for 2030 and 2100 (RCP 8.5) with 2000 emissions are designed to separate the effects of climate change on constituents and for isolating aerosol indirect effects more cleanly using the clear - sky / all - sky flux diagnostics. (giss.nasa.gov)