The reactions of CO2 on the Al-100(+) cluster have been investigated as a function of cluster temperature (300-1100 K) and relative kinetic energy (0.2-10 eV). Two main products are observed at low cluster temperature: Al100O+ (which is believed to result from a stripping reaction) and Al100+CO2+ from complex formation. As the cluster temperature is raised, both products dissociate by loss of Al2O. Al100O+ forms Al-98(+), while Al100+CO2+ forms Al98CO+ and Al96C+. In both cases, loss of Al2O turns-on above the melting temperature of Al-100(+). This presumably occurs because the overall reaction leading to the loss of Al2O is significantly less endothermic for the liquid cluster than for the solid.