On October 31, 2011 the world population will reach 7 billion people. According to the latest population projections by the United Nations Population Division, it took only 13 years to add another billion people to the world's population. Despite declining rates of population growth, another 3 billion people will be added by 2100, mostly in less developed countries. This demographic change is taking place in a globalizing world, as improved transportation and communications leads to greater mobility of goods, capital and people, and as socio-economic and political trends converge in both developed and developing countries. With regard to recent global demographic trends, life expectancy at birth has increased, fertility has fallen, the share of older persons in the population is rapidly rising, and there are more international migrants than ever before. Despite this convergence, certain demographic disparities remain between developed and developing countries. These disparities must be addressed in order to improve the prospects for development and sustainability for all.