Increasing concerns of global climate change have stimulated research interests in all aspects of carbon exchange. This has restored interest in leaf photosynthetic models to predict and assess changes in photosynthetic CO2 assimilation in different environments. This is a comprehensive presentation of the most widely used models of steady-state photosynthesis by an author who is a world authority. Treatments of CO3, CO4 and intermediate pathways of photosynthesis in relation to environment have been update to include work on antisense transgenic plants. It will be a standard reference for the formal analysis of photosynthetic metabolism in vivo by advanced students and researchers.