Glastonbury festival in England banned single-use plastic bottles in an effort to decrease the event’s impact on the planet. Naturalist David Attenborough told festivalgoers they were making a positive change.

“That is more than 1 million bottles of water that have not been drunk by you in plastic,” Attenborough said. “Thank you, thank you.”

Attenborough has dedicated his life to making nature documentaries and has lately become more vocal about the impact of human action on the animals portrayed in his films.

In 2017, more than 1 million single-use plastic bottles were sold at the festival, prompting this year’s ban on the sale of water, soft drinks and alcohol in plastic bottles.

Music festivals around the world draw millions of visitors every year, CNN has a few suggestions for how festivalgoers can make changes to decrease their impact on the planet. The article suggests avoiding glitter and single-use plastic bottles, as well as taking the bus instead of driving alone.