Out of the nearly 7 billion people alive today, imagine for a moment what the most powerful individual on the planet might look like. Chances are, you aren’t picturing a 12 year old school girl raising her hand to answer a question in science class. But the truth is that the world’s 700 million adolescent girls may just be the most powerful agents we have to address the urgent challenges facing our crowded planet.

On average, girls with at least seven years of schooling will marry…