Thousands of fans, many holding stainless-steel pint cups, sticker-covered water bottles and aluminum cans, cheered as Jack Johnson took the stage Friday night. Before he began his set at the Merriweather Post Pavilion in Columbia, Md., the grounds were bustling as crowds formed around a stand selling tote bags, reusable utensils and "climate offset" stickers among the usual concert merchandise.
On the venue's jumbotrons, one slide - interspersed with images of environmental advocacy groups - reminded people to recycle and compost at the show.