Recent laboratory work has arrived at a value of the rate coefficient for the room temperature O atom vibrational relaxation of NO(&ngr;=1) which is nearly one third the previously accepted value [Fernando and Smith, 1979>. Laboratory measurements have also established a new value for the rate coefficient for the photodissociation of NO which is ~1.6 times the previously accepted value. Since the NO(&ngr;=1→&ngr;=0) emission, around 5.3 &mgr;m, is a very important cooling process in the lower terrestrial thermosphere, the new values of the two rate coefficients lead to a decrease in the amount of NO as well as the rate at which it cools. Using the global mean model [Roble, 1995> of the mesosphere, thermosphere, and ionosphere, we find that the new rate coefficients introduce large changes in the thermal and density structure of the atmosphere. The resulting model atmosphere appears unrealistic. We find that these large changes are moderated and the resulting neutral temperatures agree better with the Mass Spectrometer Incoherent Scatter (MSIS) model when the value of the CO2+O rate coefficient for excitation of the bending vibration is increased two fold to the value arrived at by modeling the 15 &mgr;m emission from CO2 from the lower terrestrial thermosphere. Finally, we describe the results of a number of runs with the thermosphere/ionosphere/mesosphere electrodynamics general circulation model (TIME-GCM) to examine the global temperature, composition, and circulation changes that result from using the new rates for both NO and CO2. ¿ 2001 American Geophysical Union