BRISTOL, England — When the British band Massive Attack was halfway through a West Coast tour in 2019, flying from show to show, rapper and singer Robert Del Naja had a moment of crisis. Given all the carbon emitted by moving the band and its equipment around, he recalled wondering: Can I justify this anymore?

Not long afterward, the band made a decision. It would work with climate scientists to develop a model for touring that made as little climate impact as possible.

On Aug. 25, Massive Attack staged a daylong 35,000-person festival in the band’s home city of Bristol to showcase the carbon-cutting measures it has developed with the Tyndall Center for Climate Change Research, a British organization, and A Greener Future, a nonprofit focused on lowering the music industry’s emissions.

Whereas other bands, including Coldplay, have staged attention-grabbing stunts to draw awareness to the industry’s climate impacts, they have sometimes ignored the main sources of emissions from gigs, such as audience travel and venues’ power supplies. With its show last month, Massive Attack wanted to show how to tackle all of the polluting parts of a show.

In an interview a few days before the event, Del Naja said previous music industry efforts to cut emissions had not been in line with the United Nations-agreed goal to stop average temperatures rising more than 1.5 degrees Celsius, or 2.7 degrees Fahrenheit.

“If what you’re doing’s not 1.5 compatible, it’s irrelevant,” Del Naja said. “It’s simply a gesture, an idea. It’s not doing anything.”

Del Naja then gave a tour of the festival site, pointing out metal boxes filled with batteries charged by wind and solar power that would provide all the electricity, as well as electric trucks that would ferry equipment between stages. All the catering, including backstage, would be vegan.

At one point, Del Naja walked up to a row of portable toilets. “Have you seen the compost loos?” he said. “They’re really cool.” The band would send some of the event’s waste to a firm that extracted phosphorous from urine, he explained.

The on-site changes will make some difference, but much of a show’s pollution comes from elsewhere. In 2007, the British band Radiohead published a study showing that audience travel was responsible for more than 80% of emissions for its tours.

Since then, few artists have had success tackling that issue.

Billie Eilish’s team, for instance, emails ticket holders about public transit options before her gigs and, for a recent Los Angeles album launch, worked with LA Metro to increase services to the venue — although many fans would have had to first drive to a station.

Massive Attack tried several measures to encourage sustainable travel to its Aug. 25 festival, including offering Bristol residents the first chance to buy tickets, because they were more likely to walk or cycle. The band also negotiated with a local train company to provide extra services. And it hired a fleet of electric coaches to whisk attendees to and from Bristol city center to the festival site.

The Tyndall Center will publish a report this fall detailing the event’s climate impact, and Massive Attack will incorporate lessons from the study at coming gigs.

Del Naja said he hoped that promoters and venues would also learn something from the experiment. But he was realistic: In places like the car-loving West Coast of the United States, he said, bands need lawmakers to overhaul transit systems to make it easier to avoid flying and driving.

The need for change is becoming more pressing because fans are increasingly traveling farther to see their idols. Numerous American fans of Beyoncé, Taylor Swift and Adele flew to Europe to see those acts after failing to secure tickets closer to home. “The music industry has to work out a solution to that trend,” said Christopher Jones, a Tyndall Center researcher, “otherwise emissions are going to keep going up.”