Book excerpt: This book discusses the role of energy in agriculture which reaches 30%, and the role of agriculture in energy where the water shred by 17% in total electricity generation in addition to the role of bioenergy as a source of liquid energy. Climate change and global heating will increase the temperature and that will affect plant growth, water availability and the share of electricity in agriculture and other energy phases in agriculture. Global heating means more water pumping, more uses of fertilizers and pesticides in which intensive power consumption in addition to need of more electricity for air-condition inside the greenhouses, the manufacturing of hormone and plant growth organizers will also consume more energy. Finally, the book explains why the water, energy and food become one nexus and the interaction and interference between them. This book will have valuable information for both students and faculties of engineering and agriculture in addition to research centers, water institutions and climate change specialists.