(2021-03-24) The cpl hist data here were copied from:
/glade/campaign/collections/cmip/CMIP6/cpl_hist/b.e21.B1850.f09_g17.CMIP6-piControl.001.cpl.hl2x1yr_glc.1201-2000.tar

(Note that these years have no correspondence to real-world years: I
think they are just the last 30 years of a 2000-year spinup.)