Energy, water and food were and still are three interwoven and major elements that ensured human civilization’s survival. This intricate relationship is known as the water-energy-food nexus (WEF).Energy sources played a crucial role for the development of mankind from the discovery of fire to the agricultural revolution and subsequently the industrial revolutions  of the last centuries. Human societies have developed over the centuries because of access to abundant and safe energy sources. But environmental problems generated from the development of high-carbon energy fossil fuels, became lately a threat of climate change and rising sea water levels in most parts of the Earth.The world of energy systems is entering a new historical period with fundamental shift to low-carbon energy sources. Renewable energy sources witnessed unprecedented growth in the last decade. Decarbonization, CO2 sequestration and storage are also essential in the near future.Agriculture and the food industry (the agri-food sector) are changing dramatically in the last decades to meet sustainable goals and better efficiency. There are high expectations for reduction of the 50% of the plant-habitable surface of the planet used by agriculture and reduction in the use of 70% of fresh water. World is focusing in present agriculture which is responsible for 30% of greenhouse gas (GHG) emissions], while farmers can increase carbon sequestration by environmentally practical steps that increase crop residues and organic matter stored in the soil. Also, expansion of forests and other improved biological sinks can reduce CO2. Fresh water is at the core of sustainable development and is critical for socio-economic development, healthy ecosystems and for human survival itself. Fresh Water is also at the heart of adaptation to climate change, serving as the crucial link between the climate system, human society and the environment. Water is a finite and irreplaceable resource that can be protected and can be renewable if well managed. Today, 1.7 billion people live in river basins where depletion through use exceeds natural recharge, a trend that will see 2/3 of the world’s population living in water-stressed countries by the next decade. Lack of adequate freshwater can pose a serious challenge to sustainable development in less-developed countries.