There are many climate change activists who had a huge impact on society. Without them, there wouldn't be as much awareness about climate change and people would not be taking as much action to reduce greenhouse gas emissions.
I have an article on these climate change activists:
I should point out that I myself, Laurent Cousineau, have been an activist for over a decade (although not famous).
I have a list of documentaries and other films that I recommend.
For Al Gore, there are two documentaries:
For Leonardo DiCaprio, there are two documentaries:
For Bill Gates, there is a documentary called Inside Bill's Brain: Decoding Bill Gates
Also, there are Ted Talks from: