He grew up at a time when the Marshall Islands were used for 67 US nuclear bomb tests. When he was nine years old he witnessed the "Castle Bravo" detonation, while fishing with his grandfather around 280 miles away.
He studied history and linguistics at the University of Hawaii at Manoa, and received a degree in psychology.
In 2016, the International Peace Bureau nominated him for the Nobel Peace Prize.
He was the Marshall Islands foreign minister and was instrumental in securing the Paris Climate Agreement. He was a champion of the rights of small island nations.