Since I was very young I've been fascinated with nature and I actually wanted to be a marine biologist when I was very young. That was a great passion of mine. So I suppose in the off season when I'm not making movies, I became more and more active as an environmentalist trying to be more vocal about issues that I felt were important.

I lived in Hollywood and, ironically, I didn't know you could just go out and get an agent and go on auditions and try and become an actor, I thought it was like a Masonic thing, like a blood line you had to belong to – until I was 13. Then I realised what you had to do. It is the one thing I know I want to do for the rest of my life.

Will this coffee get me an Oscar?

Now is the time to divest and invest to let our world leaders know that we, as individuals and institutions, are taking action to address climate change, and we expect them to do their part this December in Paris at the U.N. climate talks.

I like movies! No, I like theater too. And paintings are great, and all of that! But to me, the great sort of artistic medium I think, of our time, is film. I really feel that. I mean to me, there's nothing else out there, where I can sort of suspend disbelief for two hours.

It's interesting in this day and age to do a film about political espionage and wiretapping. I don't think that those types of secrets that J. Edgar Hoover was able to obtain and keep for such a long period of time would be possible in today's world, with the Internet and WikiLeaks.

It was invaluable to have a dear friend who you have known for over a decade, be a partner in a film like Titanic. To have somebody that talented to work against, who's also your friend and who you know you have the best intentions for and vice versa, and who you intrinsically trust to give you their forthright honest opinion about what we're both doing - all that's something you can't really buy.