The effects of climate change have the potential to greatly reduce agricultural production in the future. However, relatively little is known about whether there will be enough water to meet growing demands for food under an increasingly variable climate. GFI researchers are seeking ways to estimate how much water is required for current and future food production in regions where food security is vulnerable. These investigations account for not only rain-fed production systems, but look at where and how much water is needed to introduce irrigation in areas where agricultural water shortages may be limited in the future.