Two dozen students, parents and teachers from St. Xavier High School observed the effects of climate change first-hand during an “Xpedition” to Africa that took them into the Serengeti and to the top of Mt. Kilimanjaro June 2 to 18.

A trek to the summit of the mountain — the highlight of their journey — took them from forest to alpine desert where colossal glaciers are melting into chunks of residual ice. In the midst of altitude-induced fatigue and the daily toil of a 10-day hike, the group studied these ecological zones and learned about the impact of a changing climate.

“It was literally a walking classroom to educate the young people,” said Michael O’Toole, a St. X teacher and the expedition’s organizer. He and two professors from the University of Louisville provided a framework for these lessons.

While science was one focus of the trip, much of the group’s attention was captured by the day-to-day attractions and hardships the adventure presented.

Each day on the mountain, the temperature rose to about 80 or 90 degrees. But at night it fell to below freezing.

“When we exhaled at night, our breath would hit the top of the tent and, it would snow down on us,” O’Toole noted. “You had trouble sleeping very long in those conditions. I woke up 10 or 12 times through the night.”

The group from St. X included teacher Frank Hulsman, his wife Elaine and their daughter Christy, 15 St. X students, five fathers of the students, U of L professors Keith Mountain and Inka Weissbecker, and more than 60 Tanzanian porters who hauled the group’s gear up the mountain.

Some people who trek to the summit of Mt. Kilimanjaro take a five- or six-day route, said O’Toole. But it’s often a more difficult journey, and not everyone in the group makes it to the summit. He selected a longer 10-day route to ensure his group would be adjusted to the altitude and prepared to enjoy summit day at an elevation of more than 19,000 feet.

The route “allowed us to gain elevation and drop so we could get acclimated,” said O’Toole, noting that the group spent a lot of time at each vegetative zone learning about their surroundings. The altitude gave some people headaches and made them feel more tired than “we thought we should be,” said O’Toole.

Matt Morris, who will be a senior at St. X this fall, said, “The last two days were the hardest. We were walking through volcanic ash, and you’d sink six or seven inches. We’d have to stop every hour for like 20 minutes just to rest and regain our footing.”

The group documented their hike with high definition video and photos that O’Toole is uploading to the Xpedition Web site — www.xpeditiononline.com. He hopes other youths will log on and take a “virtual safari” when all the information is uploaded.

The extensive site is kid- and teacher-friendly. O’Toole and his students designed it over the last year to help people learn about climate change.

Each night along the trek, Morris said, he recorded where he climbed, what elevation the group reached and what he learned and felt about the day’s adventure. Selections of his entries and those of others who kept journals also will be posted on the site.

Near the end of their journey, the group spent a full day at the summit’s base camp, called crater camp, that stands at 18,700 feet. There they explored the glaciers and the mountain’s volcanic features.

About 1,000 feet above crater camp stands Uhuru Peak — the mountain’s highest point. On summit day, the St. X group could see the peak for a half mile before they reached it. O’Toole went ahead of the group and videoed each person’s arrival at the summit. O’Toole plans to post that footage on the Web site, too.

When everyone was gathered at the summit they popped champagne bottles and raised the St. X flag. Each person in the group, including the porters, signed the flag, which has been framed and will hang at St. X.

“Everyone had one bad day — sickness or altitude trouble,” said O’Toole. But “26 of 26 made it. It’s very unusual for that many to make it.

“Another group arrived while we were celebrating, and they were sick — throwing up,” he noted. “I’m sure they were wondering how we were doing so well. Anything above 16,000 feet is tough. To hike at that altitude is one thing. But to stay at that altitude, you have to acclimate.”

For Ben Dant, who will be a senior at St. X this fall, reaching the summit “was the best part — having the feeling of finally getting it done and seeing everyone else’s reactions.”

“It was amazing,” he said. “I was just ready to enjoy the moment.”

Reaching the summit also meant the group would soon eat a hearty meal. During the trek, Dant said they subsisted on soup for the most part — cucumber soup, potato soup, onion soup. He lost seven pounds during the expedition.

In addition to reaching the summit of the world’s tallest free-standing mountain, the St. X group also explored the Serengeti region of Tanzania; visited a church, orphanage and school in Moshi, a large Tanzanian city; and encountered the legendary Maasai warriors.

For most of the young men on the Xpedition, “this was their first experience of a third-world country,” said O’Toole. “It was eye-opening.”

“The physical beauty we were anticipating,” he noted. “But the beauty of the people was wonderful. They were so open and so welcoming. We were on the far side of the world, but always felt at home with the people we met.”

The group attended Mass — celebrated in Swahili — at Christ the King Cathedral in Moshi and visited with parishioners there.

They also took donations of clothing and sporting goods to a local school and an orphanage. Each of the 26 people on the trip took one bag with their own gear and another bag of donations for the children. Items were donated by individuals and GE.

Out on the Serengeti, the group set out one morning before sun-up and encountered a pride of lions. Morris said this was his favorite part of the trip, sitting in a Land Rover “watching lions with the sun rising in the background.”

At one point, he said, the group’s train of Land Rover’s came within 10 feet of a female lion stalking a gazelle. The lion pounced on the unsuspecting animal. But before she killed it, she gave her cubs a chance to practice pouncing. When the cubs had practiced enough, a male lion stepped in and ate his fill.

“It was awesome,” Morris said.

O’Toole plans for his students to share these experiences and what they learned about climate change with schools around Louisville. And the Web site will continue to be updated, he said. It offers lesson plans for teachers and easy-to-understand explanations for kids, including a section on how to “make a difference,” he said.