Inside the massive metal-clad furnace at the center of Pratt Fine Arts Center’s glassblowing facility, a ceramic bowl holds a thousand pounds of clear, molten glass. Before its dipped into powdered pigments, the glass is kept liquid thanks to a constant temperature hovering near 2,000 degrees Fahrenheit, fueled by a continuous stream of natural gas.

“It stays on 24 hours a day, seven days a week. For years at a time,” says Darlington, glass studio manager at Pratt. Heating the equipment sucks up so much energy and time that there’s no use in turning it off. It burns at least 84 cubic feet of gas every hour. Next to the furnace, three reheating ovens (also called glory holes) gobble up a minimum of 100 cubic feet of gas each hour they run.

Pratt’s fuel usage is not exceptional. While the glass art industry blows oxygen and life into intricate glass chandeliers, vases, bowls and complex sculptures, it also consumes hefty amounts of natural gas and propane while filling the air literally with tons of carbon dioxide. Other issues, like heavy metal pollution and low levels of recycling, add to the industry’s sustainability concerns.

“So much of the process of making glass adds to global warming, from the fuel that we use to the resources we are depleting,” says Brandi P. Clark, executive director of the Glass Art Society, a Seattle-based nonprofit with worldwide reach.