In the Washington Post today Graça Machel and Desmond Tutu write about this scourge:
"If adults know child marriage is wrong, why do they allow it to happen?" a teenage girl asked one of us during a visit this year to Bihar, a state in northeast India where, despite national law to the contrary, 69 percent of girls are married before age 18.
For far too long, "tradition" has been the default answer. Child marriage happens, we are told, because it has been arranged for generations, because that is "the way things are." But traditions are man-made, and we believe that when people realize a tradition or practice is detrimental, they can and do change them.
Child marriage happens because adults believe they have the right to impose marriage upon a child. This denies children, particularly girls, their dignity and the opportunity to make choices that are central to their lives, such as when and whom to marry or when to have children. Choices define us and allow us to realize our potential. Child marriage robs girls of this chance.
You can read the rest here, about efforts being made to challenge the practice. Tradition is never an adequate justification for a fundamental harm or violation of an important human right. Machel and Tutu rightly insist that that is what child marriage is.