There are people who devote more of their time to volunteer work than Carl Schmitt does, but it's hard to imagine anyone volunteering at a higher altitude.

Schmitt, a project scientist at the National Center for Atmospheric Research and a mountaineering hobbyist, has led two different month-long trips to Peru, where he and a team of scientists evaluated the make-up and quality of snow and ice in Huascaran National Park, the world's largest expanse of tropical glaciers.

"The minimum altitude of glaciers is about 17,000 feet, so I don't start doing any collections until we get over that," said Schmitt, 42, whose work has taken him as high as 21,000 feet.

Glaciers in the high Andes of South America are rapidly retreating, provoking concerns about the future of Peru's water supply for drinking, hydropower and agriculture. As scientists work to prepare for future water-related crises, they must determine the extent to which glacier ice is being darkened, and then melted, by particles emitted by industrial activity.

"It's important work, because the whole idea is that we want to better understand the glacier melt rates and the water cycle in the region," said Schmitt, who earned his doctorate at the University of Colorado.

"It's really something where I feel like we can have a pretty solid impact. These things are happening, and (Peruvians) need to prepare for it so that, 30 years down the road, they don't have a crisis."

The group Schmitt volunteers for, the American Climber Science Program (ACSP), has been collaborating with local residents, officials and scientists. They've also presented their research to graduate students at a university in Huaraz, Peru.

Schmitt relishes the chance to interact with locals.

"My work at NCAR has a lot of impact, but I'm not in touch with the people it impacts. It's not like the human connection you get working with people like this. That's a lot of why I do that. I feel like I can definitely make a difference and help people," he said.

The ACSP's first two trips to Peru had budgets around $70,000, almost all of which comes from the scientists' pockets. Schmitt pays his own way to Peru, and also buys all the necessary equipment. The financial sacrifices he's made, however, pale in comparison to the time he's dedicated to the glacier project.

"Every vacation day I have goes to the Peru work," he said. "And in addition to doing the work while I'm there, I probably spend 40 hours per month off the clock working on data analysis for Peru."

The ACSP is planning another trip to Peru for this summer, but the group hopes to expand its research area if it can get more funding. Schmitt wants to lead a trip to Argentina's Aconcagua, which, at nearly 23,000 feet, is the tallest mountain in both the Western and Southern Hemispheres.

It'd be a challenging summit, but Schmitt has toppled enough massive peaks to know how to approach a possible venture to Aconcagua.

"You just have to make some decisions scientifically, in terms of where you're going to collect samples," he said.

"My philosophy is always that you shouldn't be working on a mountain that's at the limits of your ability, because you've got a lot of other things to worry about." Contact Camera Staff Writer Alex Burness at 303-473-1361 or burnessa@dailycamera.com.