One formative experience for him as a child was witnessing the fallout from nuclear testing at Bikini Atoll. He witnessed the sky turn "blood red" when out fishing with his grandfather as a nine-year-old boy.[7] For that reason, he was outspoken about the issues of nuclear testing and led a lifelong campaign for nuclear disarmament.[2] In 2014, he filed unsuccessful lawsuits at the International Court of Justice against all nine states that have nuclear weapons, describing the weapons as "a senseless threat to essential survival."[6] He linked the issue to climate change, and declared that it was "repugnant" for any citizens to have to leave their islands due to sea level rise having already had to flee the fallout from nuclear testing.[8]
He was an outspoken proponent for ocean thermal energy conversion technology (OTEC) and tried to get the US and Marshallese governments to agree to build a 20 MW floating OTEC power plant by Kwajalein atoll in the Marshall Islands in association with Energy Harvesting Systems of Honolulu, Hawaii. On Kwajalein the local children nicknamed him "Mr. OTEC".[14]
Awards
DeBrum won the 2015 Right Livelihood Award in recognition of his "vision and courage to take legal action against the nuclear powers for failing to honour their disarmament obligations under the Nuclear Non-Proliferation Treaty and customary international law.".[15]
Personal life
DeBrum is the uncle of Marshallese climate envoy Tina Stege.[16]