A global stratospheric aerosol database employed for climate simulations is described. For the period 1883--1990, aerosol optical depths are estimated from optical extinction data, whose quality increases with time over that period. For the period 1850--1882, aerosol optical depths are more crudely estimated from volcanological evidence for the volume of ejecta from major known volcanoes. The data set is available over Internet. ¿ American Geophysical Union 1993