In just one year, the Japanese state’s biggest emitter morphed into its most progressive clean power buyer. And more dramatic developments are yet to come.

Japan’s Self-Defense Forces (SDF) are best known for their prowess in dealing with natural disasters rather than for military exploits. This experience has given the SDF a unique and hands-on understanding of climate change’s impact on national security.

For the first time the SDF has framed its concerns as a national security issue, joining an array of militaries from around the world in publicly discussing climate challenges.

The SDF also published results of its initial efforts to switch energy supplies to renewable sources. The results are impressive