During their time at the University of Colorado, graduating seniors have basked in the spotlight of a Sierra Magazine rating that crowned the Boulder campus the most eco-friendly in the country.

They've cheered on the Buffs in a college football stadium that was the first in the nation to go zero-waste. And they've taken classes in new buildings that are the gold standard for green construction.

So it seems that a "green" graduation gown -- made from recycled plastic soda and water bottles -- is just the right fit.

The Class of 2011 will be the first at CU to flaunt sustainable gowns. And an increasing number of graduating seniors have taken a "green pledge," promising to be mindful of their carbon footprint as they take that leap into the real world.

Departmental ceremonies are Thursday, and the university-wide commencement ceremony is Friday.

CU was interested in switching to the greener gowns for the past few years, said Allison Hartell, assistant director of marketing and outreach for the CU Bookstore. But until this year, the gowns had been much pricier than traditional regalia.

"CU is recognized as an environmentally friendly campus," she said. "It seemed like the time was right and the price points were right."

Students receiving their bachelor's degrees pay $38.99, slightly more than last year's price. The gowns were ordered from Willsie Cap and Gown.

This year, 300 graduating seniors have signed a pledge to be socially and environmentally responsible when they enter the workplace, said Greg Swenson, a campus spokesman. The pledge debuted at the Boulder campus in 2007 and, at that time, 200 students made the commitment.

The students pledge "to consider the social and environmental consequences of choices I make in my personal life and work, and (to) act with integrity in my workplace and community."

Chelsea Gifford, a CU graduating senior from Nashville, Tenn., has signed onto the pledge.

She wrote her honor's thesis on honeybees and will be working with beekeepers this summer.

She's concerned that pollution -- and people's lack of commitment to sustainable lifestyles -- will threaten the environment of honeybees and, ultimately, food sources because they are pollinators.

"The green pledge is easy to sign because for me, there is no other way to live life," she said. "If we want to stick around as a species, we need to start thinking of ourselves as a part of nature, not above it."

Graduating senior Dan Omasta, who double majored in political science and environmental studies, also signed the pledge. As a student leader, he served as the sustainability director for two years.

This summer, he'll be working in Boulder on sustainable food and community garden projects before heading to Vancouver to work on a sustainable farm.

"CU teaches students to be positive citizens in the world," Omasta said. "The green pledge signals that we, as Buffs, are going to go out in the world and start sustainable businesses or make the companies and communities we live in sustainable. We can't wait for government policies to come down the chain of command. It has to be grass-roots."

Contact Camera Staff Writer Brittany Anas at 303-473-1132 or anasb@dailycamera.com.