The world’s population will reach 7 billion people on Oct. 31, 2011, and according to United Nations projections, we are on pace to add 3 billion or more by the end of this century. Already, millions of women in developing countries are unable to determine the size of their families because they lack access to contraception. Worldwide, the largest group of young people in history is entering their reproductive years. The decisions and policies we make today, and the options available to these young people, will ultimately determine whether our numbers climb to anywhere from 8 billion to 11 billion by 2050.