history: Mon Apr 23 08:25:23 2018: ncatted -O -a blah,global,a,f,1.0 biomass_0.5x0.5.nc Mon Mar 21 09:05:59 2016: ncatted -a units,biomass,o,c,kg m-2 ./from_MQs_site/DATA/biomass/GEOCARBON/derived/biomass_0.5x0.5.nc tmp.nc

  blah: 1.0