Since CDO version 1.0.6, three new environment variables were introduced:
- CDO_DISABLE_HISTORY:
  If set to 1, the netCDF history attribute of input datasets is not used.
- CDO_DISABLE_FILESUFFIX:
  If set to 1, file suffix (.grb, .nc, ...) will not be added to the output
  file name of split*.
- IGNORE_ATT_COORDINATES:
  If set to 1, netCDF variable attribute "coordinates" will be ignored.