It's likely that few of the students, faculty and staff at UNC give much thought to where the power that turns on the lights, computers and lab equipment comes from.

But some of them do, and they've started to ask important questions about it. Student activists and the Sierra Club have been pushing the university to wean itself off coal and, in the meantime, more closely monitor the practices of the companies from whom it buys that coal.

Chancellor Holden Thorp responded recently by establishing a task force to study the complicated issue of how UNC can best reduce it carbon emissions.

UNC's cogeneration plant on Cameron Avenue produces up to one third of the electricity used on campus, and all of the steam, which powers heating systems, water heaters and other equipment.

The plant produces that power by burning coal and natural gas.

Although Thorp said UNC uses best practices to reduce the detrimental effects of burning coal -- indeed, the power plant has won awards for cleanliness and efficiency -- the Sierra Club says coal use is nevertheless responsible for more than 60 percent of Carolina's greenhouse emissions.

In pledging to reduce its coal use over time, university officials tacitly acknowledge that coal is an undesirable energy source.

The university's timetable calls for the plant to become carbon neutral by 2050. Students and the Sierra Club are urging the university to drastically hasten that process, by increasing the ratio of natural gas to coal while renewable energy sources are phased in.

From where we sit, just down Graham Street from the cogeneration plant, 40 years, in this context, is so long a time as to be almost meaningless. Given the gravity of the situation and the likelihood of new green technologies in the years to come, we'd like to see Carolina set a much more ambitious target.

In the short term, the university should divest itself from ties with companies that engage in the most destructive coal mining practices such as mountain top removal -- which, we're sad to say, is just what it sounds like.

"The coal that we purchase is not mined from mountaintops, according to our suppliers," Thorp said. The qualifier at the end of that sentence is key. According to several sources, Red River Mine, one of UNC's largest coal suppliers, engages in mountain top removal.

The university's coal contracts come up for renewal this summer. Carolina, a progressive and public-minded institution, should require that whatever companies it does business with refrain from mountain top removal and similarly destructive practices -- and should know better than just to take the coal companies' word for it.