The yield of rice, a ‘C₃-type’ grass, is limited by the inherent inefficiency of C₃ photosynthesis. On multiple independent occasions evolution surmounted this inefficiency through the establishment of the C₄ photosynthetic pathway. C₄ species such as maize and sorghum are more efficient at carbon assimilation than C₃ species, and in addition they display greater water use efficiency, better nitrogen use efficiency and higher-temperature tolerance. The underlying hypothesis of this research is that photosynthetic efficiency in rice can be improved by engineering the photosynthetic machinery to include functional components of the C₄-type pathway, and that increased photosynthetic efficiency will result in higher yield plus greater resilience to abiotic stresses associated with climate change.