A unique seminar on environmental issues involving prominent Jewish thinkers, environmental activists, businesspeople, academics and local politicians will be hosted by the University of Colorado at BoulderÂ’s Environmental Studies Program Oct. 17. The seminar is the first event of a new project the National Jewish Center for Learning and Leadership, or CLAL, has begun to bring together people with diverse perspectives on environmental issues for study and dialogue, said Rabbi Robert Rabinowitz, a senior fellow at the center. CLAL is based in New York City.