The president-elect’s defense secretary nominee James Mattis may turn out to be the greenest person in Donald Trump’s Cabinet. Trump’s incoming administration is loaded with high-ranking fossil-fuel promoters and climate-change skeptics. But Mattis stands out as one of the military’s most vocal advocates for weaning the armed services off traditional energy. The retired Marine Corps general joins other military planners in identifying the potential upheaval around the world from climate change as one of the biggest security threats facing the U.S. in the coming decades.
