Issues causing increased water stress and availability throughout the world are complex.The importance of supply-side issues arising from increasing urbanization, causing localized levels of water stress, is described.As well, while the world population has doubled over the last 50 years, water use has tripled, from 400 km3 per year per billion people, to the current level of 600 km3 per year per billion people.The rapid increase in demand-side water use is, most importantly, attributed to population growth with its associated food and energy implications,and dietary shifts of populations.Projected population growth impacts, with its needs for food and energy are described.These demands will require larger water quantities going forward.These will require future water quantities in 2025 to be 60# more than current volumes, or approximately 1500 km3 per year.Increased world energy demand will involve a six-fold increase in water demand in 2050 relative to 1965, as a result of the combination of projected energy consumption per capita, and the growth in the world's population.The majority of the changes in water use have taken place in the agricultural sector although this sector's use of water as a percentage of total water demand is decreasing, as the domestic and industrial components increase.These various findings indicate that while climate change is important to water security issues, the implications to water security from population and its ramifications (food and energy) and changing habits/diets are of greater concern.