About 75 percent of students already walk, bike, take the bus or use other modes of transportation to get to campus, said Dave Newport, director of CU's Environmental Center.

Environmental and university leaders recommend that campus parking be limited to faculty and staff members, or a small number of students. The Daily Camera newspaper reported the change could cost the school up to $1.2 million a year in revenue from student parking permits it now sells.

Last week, the university filed its plan for reducing campus energy consumption and greenhouse gas emissions with the American College and University Presidents' Climate Commitment. It has submitted ideas that include installing motion sensors that can automatically turn off lights in empty classrooms and using eco-friendly building standards.

Newport said the school is "seriously considering" the parking ban for students.

"You don't really need your car here 95 percent of the time," Newport said. "Boulder is so good at alternative transportation."

Student fees cover bus passes. The campus has about 65 bikes to rent, as well as a program that allows students to check out cars and a carpool system.

About 45 percent of faculty and staff members drive to the campus because many live farther away, Newport said.

School leaders said the ban must be well planned and communicated so streets aren't flooded with cars and so the plan doesn't create an unstable budget for the school's parking and transportation department.