Los Angeles, Dec 22 : Hollywood actor and environmentalist Leonardo DiCaprio, who is gearing up for the release of his upcoming film 'Don't Look Up', says he often in his career looked for a film that had an environmental undertone to it. Talking about the movie, Leonardo said, "I've often in my career looked for a film that had an environmental undertone to it and what Adam did was so brilliant, using the analogy of a giant comet heading towards Earth and showing how the human race would react to it from a political and scientific level, which I had never seen before." He added: "It was a once in a lifetime opportunity in a lot of ways. I'm a huge fan of a lot of these films that came from the '60s and '70s - 'The Parallax View', 'Three Days of the Condor', certainly 'Network' and, of course, 'Dr Strangelove', which talked about the Cold War through dark comedy." DiCaprio and co-star Jennifer Lawrence both consulted Dr Amy Mainzer, an astronomer and climate change scientist who served as an advisor to the cast and crew remotely. DiCaprio credits Dr Mainzer with helping him for his role. He said: "I must've had 100 conversations with her. I've spoken to many climate scientists, but our discussions were taken from the viewpoint of an astronomer. It was amazing to see the parallels in their thinking." 'Don't Look Up' is releasing on December 24 on Netflix. /IANS