SAN JOSE, Calif. – David Kroodsma – an Ultimate Frisbee-playing, climate-studying scientist – is out to improve the world, one bike ride at a time.

On Saturday, Kroodsma will climb on his modified bike and begin cycling from Palo Alto, Calif., down the length of the state, then pass the dusty colonias of the Baja peninsula. He’ll push on through Mexico, Central and South America, ending, an exhausting 14 months and 13,000 miles later, at the southern tip of Argentina.

Along the way, the 26-year-old will talk with students, scientists and anyone else willing to listen about global warming and how our reliance on cars and an electrified life is altering the earth’s climate.

It’s an unorthodox way to discuss science, but Kroodsma, an earnest man and avid cyclist, believes people are more likely to listen when you’re on two wheels.

“It’s an intimate way to travel,” said Kroodsma, who rode the Transamerica Trail in 2003. “When I biked across the country, it was amazing how quickly people invite you into their homes.”

Kroodsma holds a master’s degree in earth science and has been researching climate change at Stanford University. But he believes personal conversations might better coax people to change their habits than a dry scientific article.

He’ll also post travel dispatches on his Web site,, hoping that after reading about the countries and people he visits, people here will care more about those living in Latin America.

That’s crucial, Kroodsma says, because the United States is responsible for nearly a quarter of the carbon dioxide in the world but people in other countries bear the brunt of climate change. Hot temperatures can ruin crops, hurting agricultural economies. Rising sea levels and stronger hurricanes will devastate countries too poor to build levees or sturdy houses.

“My message is very simple: We need to care about these places,” said Kroodsma, who has been visiting California schools to discuss science and biking.

During his classroom visits, students have focused as much on the ride as the science. How do you plan to get back, they inevitably ask. (On a plane, he responds.)

“I think it’s cool he’ll take his own time,” said Bryant Reyna, a freshman at Mountain View High School in Mountain View, Calif.

Like many kids, Kroodsma learned to ride when he was 6 or 7 years old. His bike had a banana seat, and he remembers testing how many times he could circle the cul-de-sac.

His first bike tour didn’t come until 1999, when he and friend Tom Hunt decided to ride their bikes to school – or more precisely, from Portland to their freshman dorms at Stanford. They planned meticulously, even sawing off their toothbrushes to conserve weight. They rode 900 miles in nine days and were hooked.

Since then, Kroodsma has biked through Alaska. Another time, he and a group of college pals rode from Stanford to Las Vegas – an arduous trip in which they hiked over the Sierra, then rode through the Mojave Desert at night to spare themselves from the punishing May heat.

“We didn’t do anything when we got to Vegas,” Kroodsma said. “We were too tired.”


The longest trip so far has been that 2003 cross-country trek with his father, ornithologist Don Kroodsma, who woke his son up at 5 a.m. to hear bird songs. They amused themselves during the 4,500-mile trip by playing “Name that Road Kill.”

The journey was a rare way to see America. Away from the highways, they noticed nuanced, changing personalities of the states: the flags planted on rural Kentucky homes, the friendliness of Kansas, the over-sized RVs rumbling across Oregon.

Compared with what he’s about to embark on, that trip was easy. There were relatively good roads and detailed maps showing where the next town – and the next meal – was.

There’s no such plan for Central and South America. He’s not sure where he’ll sleep each night, but he figures it’ll be a combination of camp sites, hostels and homes of people he hasn’t yet met. He’s also hoping to fine-tune his Spanish; though he’s currently conversant in the language, he doesn’t know crucial phrases like “carbon dioxide.”


Other aspects have been carefully thought out. He’s bringing 40 pounds of gear, including a Palm Pilot to write his dispatches. He plans to only use it in his tent so he doesn’t tempt thieves. For the same reason, he’s planning to throw paint and duct tape on his modified mountain bike to make it look like a cheapie.

Kroodsma has been thinking about the trip since that first bike tour to Stanford in 1999. The timing seemed right when, as anticipated, funding ran out this year for his position at the Jasper Ridge Global Change Experiment at Stanford. There, he had been manipulating the heat, water, nitrogen and carbon dioxide on plots of grass to see how the ecosystems changed.

“I admire the things he’s up to,” said his father, who plans to join for a portion of the bike trip – probably Argentina, for the birds.

His pal Hunt, who credits a stint as captain of Stanford’s Ultimate Frisbee team for honing Kroodsma’s planning skills, says his former roommate eventually convinced him that climate change is a real danger.

“I’m a physicist, and I’m skeptical of the all the hoopla in climate change. A few degrees in climate changes doesn’t seem as dangerous as nuclear war,” Hunt said. “He’s convinced me that it’s very important.”

Hunt plans to join Kroodsma in Peru, but he admits the cause is not the big draw. “I’m coming down mostly for the bike riding,” Hunt said.

Kroodsma is as passionate about the cycling as the science. The Bay Area, with its numerous bike lanes and diverse geography, is one of the best places in the country to bike, he said.

So is he returning here after his trip?

“Depends,” he said, “on whether I want to bike Asia.”

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