
John Kerry has been a U.S. senator, a presidential candidate and a secretary of state, all after receiving three Purple Hearts for his military service in Vietnam. Now, at the age of 80, he is stepping down from what's likely his last full time job in government: the president's special envoy for climate.
Joe Biden created the position for his old friend right after taking office three years ago. And since then, Kerry has been all over the world trying to rally governments and corporations to curb the worst impacts of climate change.