Climate change will have significant impacts on the rice production systems. Many chamber experiments have been conducted to improve our understandings of the responses to increases in [CO₂], but quantitative understandings　particularly at the field level are still limited. This paper summarizes recent findings of rice responses to [CO₂] including those from field trials using the free-air CO₂ enrichment (FACE) system. The aim is to identify uncertainties in predicting future rice productivity under field conditions. Season-long　CO₂ enrichment (200 ppm above the ambient) in the field results in a decrease in the photosynthetic enhancement as the crop ages. This confirms the occurrence of down-regulation of photosynthesis under field conditions. Grain yield enhancements by FACE averaged around 15%. Extreme temperature events during the reproductive development and/or anthesis have long been known to increase floret sterility and thereby reduce grain yield substantially. Elevated　[CO₂] reduced stomatal conductance but increased canopy and panicle temperatures; this can exacerbate the heat-induced sterility. On the other hand, the FACE effect on yield was not significant in the cool year of 2003. The mechanisms of these interactive effects on grain yield need further investigation.