Rob Greenfield, knee-deep in garbage, shines his flashlight on some produce to see if it’s worth eating.

He used to jet around the country earning fistfuls of money.

Now, Rob Greenfield, a marketing entrepreneur once bent on becoming a millionaire, eats out of trash bins. He rides his bicycle across the country.

"Dude Making a Difference" is Greenfield's new book about an environmental journey of self-discovery that has gone viral.

(He's even sort of gone mainstream. Reached by phone in San Diego, the 29-year-old adventurer said he'd recently returned from filming "Free Ride," a Discovery Channel survival series set in Central and South America.)

His 272-page memoir is subtitled "Bamboo Bikes, Dumpster Dives and Other Extreme Adventures Across America."

In it, Greenfield describes riding 4,700 miles in the summer of 2013 while living mostly on waste food and shunning air conditioning, tap water and fossil fuel energy (and, most of the time, ice cream).

Greenfield camped in out-of-the-way corners or stayed with friends or Warmshowers.org bike tour hosts. He bathed in and drank filtered water from streams, lakes and leaky hydrants and plugged in his laptop just a few times.

No bike seat

He rode hundreds of muscle-burning miles across Iowa with no bike seat during a "Stand Up for Sustainability" promotion.

He pedaled through Pennsylvania moneyless, pausing in Lancaster along the way.

"Loads of religion in this city and loads of Jesus-preaching handouts," he observes in the book. Also, just like most of the rest of the country, loads of opportunities to scavenge dinner.

"We throw away nearly half of all the food we produce in America," laments Greenfield, who stocked his bike trailer with local organic food he bought wherever possible but regularly visited "the old treasure chest out back" (store dumpsters). Meanwhile, $165 billion in food is wasted annually and "one in seven are food insecure," he writes in the book.

Thunderstorms and tornadoes chased the self-described "little granola boy" on the Plains, while thirst plagued him as he traveled East. A phoned-in relationship breakup while he was in Colorado punctured his spirit.

But not for long.

"I am an extremely cheerful, happy person," writes Greenfield, who says he ultimately had a blast uncoupling from most of his material possessions. "I learned that when you have less you have more.

"I cursed only nine times," he marvels after heeding his own "righteous, rigorous" rules all 104 days of the Off the Grid Across America Tour.

Nonrecyclable trash

He ended in Waitsfield, Vermont, carrying two pounds of nonrecyclable trash he'd generated during the epic bike tour.

Pollution, materialism and climate change absolutely threaten human survival, writes Greenfield, who says the average American generates 4.5 pounds of garbage a day. Still, "Dude" is more about common sense than penance.

He rode to inspire and explore limits and to share information about the sustainable businesses he visited. He says his enduring goal is teaching "simple ways to live a happier, healthier life that will create a happier, healthier planet."

(Start by installing LED light bulbs and super-efficient water faucet nozzles, suggests Greenfield, who implores businesses to focus on a "triple bottom line" of people, planet and profit.)

Greenfield, who visited Lancaster again during a 2014 transcontinental "Food Waste Fiasco" bike tour, decided to write about his first trip after the fact.

The material was there — while biking, he'd already blogged and posted numerous RobGreenfield.TV updates from his solar panel-powered mobile office.

"Dude" hit store shelves late last month. All proceeds go to nonprofits, adds Greenfield, an ambassador for the One Percent for the Planet corporate environmental charity.

"If 10,000 people read the book I think it would be a success," says Greenfield, who reports the same number of blog hits on a recent December day.

He might write another book. But he says he definitely wants to recross America by bike.

"I continue to do adventures like that ... It's really just an excellent platform for anyone to call attention to anything they care about," he says.

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