• Denver will host a free Earth Day fair from 10 a.m. to 2 p.m. Wednesday at the City and County Building, 1437 Bannock St.
• Naropa University School of Natural and Social Sciences will host Rose Marcario, chief operations officer at Patagonia, for an Earth Day talk on “Sustainability, Leadership and Shambhala Practice,” noon Wednesday, Performing Arts Center, 2130 Arapahoe Ave., Boulder.
• Tom Gendron, chief executive of Fort Collins-based Woodward, and Dana Christensen, deputy lab director for science and technology at the National Renewable Energy Laboratory in Golden, will speak at Colorado State University’s fourth annual Cenergy Clean Tech Expo from 8:30 a.m. to 4 p.m. Wednesday, Lory Student Center, Fort Collins.
• The U.S. Chamber of Commerce and RecruitMilitary will host a RecruitMilitary Veteran Opportunity Expo, 11 a.m. to 3 p.m. Thursday, Sports Authority Field at Mile High.
