Population growth and increasing social pressures on global water resources have required communities around the globe to focus on the future of water availability. Global climate change is expected to further exacerbate the demands on water-stressed regions. In an effort to assess future water demands and the impacts of climate change, MIT researchers have used a new modeling tool to calculate the ability of global water resources to meet water needs through 2050. The researchers expect 5 billion (52 percent) of the world’s projected 9.7 billion people to live in water-stressed areas by 2050. They also expect about 1 billion more people to be living in areas where water demand exceeds surface-water supply. A large portion of these regions already face water stress — most notably India, Northern Africa and the Middle East. The study applies the MIT Integrated Global System Model Water Resource System (IGSM-WRS), a modeling tool with the ability to assess both changing climate and socioeconomics — allowing the researchers to isolate these two influencers. In studying the socioeconomic changes, they find population and economic growth are responsible for most of the increased water stress. Such changes will lead to an additional 1.8 billion people globally living in water-stressed regions.