A joint inversion system is developed for estimating the carbon fluxes in 39 land and 11 ocean regions of the globe using both atmospheric CO2
stable isotope data. In particular, a biospheric model is developed to model both CO2
fluxes over land to constrain the inversion. Relative to CO2
-only inversion, the joint inversion system improved the partition between land and ocean carbon fluxes and possibly the distribution of the fluxes among land regions as well.