Team Green is an interesting one...moreso an activities group, but they also do some environmental stuff.
Team Green | Nashville's Only Adventure Club
From their website:
Team Green creates adventures for the Middle Tennesse community and partners with exisiting events to enhance participation. Promoting a strong commitment to health, well-being, and the environment, Team Green is a leader in inspiring a closer community in Middle Tennessee by inventing hands-on opportunities to experience new activities as well as make new friends who share a similar lifestyle.
Team Green activities provide opportunities to experience the outdoors in educational and challenging ways. The assortment of excursions involves an expansive cross-section of our community—individuals can participate regardless of past experience, age, ability level, or income.
Team Green creates active journeys embracing the natural beauty of the Southeast, thereby encouraging exploration of our regional community. Yet Team Green doesn’t limit its scope, planning adventures all over the hemisphere that reach beyond the boundaries of ordinary vacations.
In addition to planning a variety of active treks, Team Green partners with community organizations to promote events focused on health, well-being, and the environment. By raising awareness of these issues and encouraging local participation, Team Green enhances the sense of community within the Middle Tennessee area.