I like how straightforward Hawking is about climate change (about 48 minutes in).
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Charlie Rose: What worries you most about the future of the universe?
Stephen Hawking: I am not worried about the future of the universe. The universe will continue whatever happens. But the future of the human race, and of life on earth, is much less certain. We are in danger of destroying ourselves by our great insensitivity.
CR: What are we not doing to prevent these disasters that we absolutely should be doing?
SH: Not acting with sufficient urgency about climate change.
CR: Do you think we will survive?
SH: Maybe. (smiles)
I went to a public lecture by Hawking at CalTech a few years ago and was blown away by the experience. The first 10-15 minutes I was keeping up, but then suddenly I realized I wasn’t getting the math. The Q & A period was also well over my head, but I was struck by Hawking’s humor and stage presence.