The best Lutheran resource for adult education forums and adult classes is Kim Winchell’s Awakening to God’s Call to Earthkeeping. It is available very inexpensively at Augsburg Fortress Press for multiple copies, but it is also on line for free downloading. Go to ELCA Environmental Resources and scroll down to the following notice:

"Awakening to God's Call to Earthkeeping" study guide (pdf)
This 50-page resource (pdf) includes both a Leader Guide and participant materials for use in faith-based small group context: adult or older youth Sunday school, Christian Education classes, women’s circles, men’s groups, congregational “Green Team,” or in a retreat setting. Members of any Christian denomination would be able to use it, with only slight modification (if desired) to incorporate materials from their own faith tradition.