A computational code for collisional-radiative rate equations has been developed to study the effects of nonequilibrium atomic and molecular processes on the population densities in an air plasma flowfield. This model consists of fifteen air species: e-, N, N+, N2+, O, O+, O2+, O-, N2, N+2, NO, NO+, O2, O+2, and O-2 with their major electronic excited states. Many elementary processes are considered in the number density range of 1012/cm3 ≤ N ≤ 1019/cm3 and the temperature range of 300 K ≤ T ≤ 40,000 K. We then compute collisional-radiative populations and total radiative emissivities. Results of the total radiative emissivity calculated from the collisional-radiative population are fitted in terms of temperature and total number density. For the validation of curve-fitted radiative emissivity, we compute a laser-induced blast wave propagation with radiative cooling, and compare with experimentally observed shock wave and plasma front displacement. We could fairly reproduce the flowfield for the blast wave induced by a pulse laser heating. From the comparison of the reduced emissivity model with black-body radiation, displacement of ionization front was slightly different due to the deviation of population probabilities.