World-renowned experts offer special insights into the various forms of C4 photosynthesis, and how they might be introduced to rice. There are differences of opinion (contrasting hypotheses) between scientists as to which form of C4 photosynthesis (single-cell and dual-cell systems) can be achieved most rapidly in rice and the ultimate effectiveness of the different forms in delivering significant yield. This book explores those differences. It begins with a broad perspective of the economic problems surrounding rice and the potential impact of failing to contain upward pressure on food prices on the poor. This book also provides critical discussion and evaluation of the new pathways to C4 rice. As a result, IRRI has formed a C4 Rice Consortium to stimulate and conduct the research needed to invent C4 rice.