The most devasting incident of radioactive contamination took place 8,000 km from the US mainland during the Castle Bravo test in 1954. The US detonated the largest nuclear weapon in its history at Bikini Atoll in the Marshall Islands, causing fallout to spread over an area of more than 11,000km. Residents of nearby atolls, Rongelap and Utirik, were exposed to high levels of radiation, suffering burns, radiation sickness, skin lesions and hair loss as a result.
Castle Bravo was just one of 67 nuclear weapons tests conducted by the US in the Marshall Islands between 1946 and 1958. Forty years after the tests, the cervical cancer mortality rate for women of the Marshall Islands was found to be 60 times greater than the rate for women in the US mainland, while breast and lung cancer rates were five and three times greater respectively. High rates of infant mortality have also been found in the Marshall Islands and a legacy of birth defects and infertility has been documented. Many Marshallese were relocated by the US to make way for the testing.
Some were moved to Rongelap Atoll and relocated yet again after the fallout from Castle Bravo left the area uninhabitable.
Rongelap Atoll was resettled in 1957 after the US government declared that the area was safe. However, many of those who returned developed serious health conditions and the entire population was evacuated by Greenpeace in 1984. An attempt to resettle Bikini Atoll was similarly abandoned in 1978 after it became clear that the area was still unsafe for human habitation.
A 2019 peer-reviewed study found levels of the radioactive isotope caesium-137 in fruits taken from some parts of Bikini and Rongelap to be significantly higher than levels recorded at the sites of the world’s worst nuclear accidents, Chernobyl and Fukushima.
Compounding the injustice of nuclear weapons testing, the Republic of the Marshall Islands is now on the frontline of the climate emergency. The government declared a national climate crisis in 2019, citing the nation’s extreme vulnerability to rising sea levels and the “implications for the security, human rights and wellbeing of the Marshallese people”.
At Runit Island, one of 40 islands in the Enewetak Atoll, rising sea levels are threatening to release radioactive materials into an already contaminated lagoon. In the late 1970s, the US army dumped 90,000 cubic metres of radioactive waste, including plutonium, into a nuclear blast crater and covered it with a concrete cap. Radioactive materials are leaking out of the crater and cracks have appeared on the concrete cap. Encroaching salt water caused by rising sea levels could collapse the structure altogether. The Marshallese government has asked the US for help to prevent an environmental catastrophe but the US maintains that the dome is the Marshall Islands’ responsibility. Hilda Heine, then President of the Republic of the Marshall Islands, said of the dome in 2019: “We don’t want it. We didn’t build it. The garbage inside is not ours. It’s theirs.”
The Runit Island dome offers a stark illustration of the ways in which the injustices of nuclear weapons testing and climate change overlap. Marshall Islanders were left with the toxic legacy of nuclear weapons testing conducted on their territory by another state. The country is now being forced to deal with the effects of a climate crisis that they did not create, including the erosion of the Runit dome.
The nations that contributed most to the crisis are failing to cut their emissions quickly enough to limit further global heating, leaving the Marshallese at the mercy of droughts, cyclones and rising seas. A recent study found that if current rates of greenhouse gas emissions are maintained, the Marshall Islands will be flooded with sea water annually from 2050. The resulting damage to infrastructure and contamination of freshwater supplies will render the islands uninhabitable.
If the US scrapped its nuclear weapons programme, it could give a portion of the billions of dollars that would be saved to the Republic of the Marshall Islands to help the country mitigate and adapt to climate disruption (see section 1.2.1 on international climate finance). The US could also use the freed-up funds to invest in its own Just Transition away from a fossil-fuel powered economy.