CALL GLOBAL_SUM_TILE_RL( tile_carbon, total_carbon, myThid )
total_ocean_carbon_start=total_carbon
total_ocean_carbon_old = total_carbon
total_ocean_carbon = total_carbon
total_carbon=total_atmos_carbon + total_ocean_carbon
carbon_diff=total_carbon-total_carbon_old
& total_carbon, total_carbon_old, carbon_diff
_RL total_carbon