Story highlights He was struck while walking along a Florida road

Charges are pending against the driver

(CNN) Mark Baumer was a man on a mission.

The 33-year-old from Providence, Rhode Island, was walking across the country, barefoot, to raise money and awareness about the environment.

But his trek ended tragically over the weekend when he was struck and killed by an SUV while walking along the side of the road in the Florida panhandle.

Baumer left Rhode Island and started his walk in October. He'd just completed the 100th day of his walk, which he documented on several social media sites.

"Climate change is the greatest threat we've ever faced as a civilization," he wrote on his web site . "A lot of scientists agree. I am not a scientist. I am a poet."

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