If you need a place to start thinking, check out this Introduction to Global Change on-line course. It's two semesters worth of material on the physical nature of global change and the human impacts involved. Try a few of the lectures. You might be amazed/shocked by what you learn.
Need more ideas? Attend a Jimmy Buffett concert! Seriously, $1 of every concert ticket sold supports Singing For Change, funding projects that improve the quality of life for people, and that empower individuals to effect positive change in their communities.
Here's a start: What in Pensacola do you value? What do you want to see changed?