When I was your age, and extremely worried about climate change, I went to live on an ecovillage with like minded people trying to demonstrate a lower-impact lifestyle.
It was terrific, highly recommended! You might find visiting a few to be a satisfying way to connect with likeminded folks.
The one I lived on was a secular, rural-US community with at the time pretty intense covenants [0] but there are lots, with widely varying beliefs.