We interrupt the grim drumbeat about climate change for an upbeat personal bulletin. BU is ahead of Boston’s target for cutting institutional greenhouse gases.

That achievement garnered one of Mayor Martin Walsh’s Carbon Cups at the recent Greenovate Boston summit. Other winners of the first-ever award included Harvard, Massachusetts General Hospital, and Brigham & Women’s Hospital.

“It’s the cream of the crop when it comes to climate action,” Walsh said of the winners before presenting the Carbon Cups in a wood-paneled amphitheater at Harvard Medical School. “These are the leaders who will set the tone not just for the city, but for the nation and the world. They’re the partners we need to achieve the most ambitious goals.”

Dennis Carlberg, BU’s sustainability director, accepted BU’s cup. The University’s “leadership has been profound over the last few years, and personally I thank Dennis for his leadership,” said Brian Swett, the city’s chief of energy, environment, and open space.

The summit, a series of workshops and talks, was the latest step in the city’s effort to combat global warming, begun under former mayor Thomas Menino (Hon.’01), now codirector of BU’s Initiative on Cities. Boston has committed to reducing fossil fuel emissions by 25 percent citywide by 2020, and by 80 percent by 2050. To meet the 25 percent target, owners with large and numerous buildings will have to cut emissions by an even greater amount, according to the city. So Walsh established Carbon Cups for building owners who cut emissions 35 percent from one million square feet of their buildings by 2020—a target BU has already hit.

“These reductions come through a three-pronged approach for greenhouse gas reduction,” Carlberg said in an interview. That approach combines energy conservation, switching from oil to cleaner natural gas for energy needs, and the effects of the greenification of the regional energy grid.

The University has committed to reducing emissions by 35 percent on a total of five million square feet of building space—the one million already achieved, plus four million more—by 2020. Gary Nicksa, senior vice president for operations, said that it “will require several million dollars a year to realize those significant carbon reductions and energy cost savings—a win-win, as it is both environmentally and economically sustainable.”

To cut energy use in the next four million square feet, he said, the University is examining large buildings with energy-intensive uses, like research, and building automation systems.

“BU’s sustainability commitment is long-term and broad-based,” Nicksa said. “It’s a significant part of our teaching and research program and campus operation.”

The buildings in BU’s Carbon Cup–winning portfolio include 10 Buick St., 745-755 Commonwealth Ave., 771 Commonwealth Ave., 25 Lenox St., 46 Mountfort St., and seven Bay State Road addresses.