A day after environmentalist Jane Goodall spoke to a full house at the National University of Singapore (NUS) where I teach, a friend asked me: "How is the environmental movement going to survive in a post-Jane Goodall, post-David Attenborough world?"

Both are eloquent communicators about the state of the environment, and communicate with credibility, sharing their experience in a way that conveys the wonder and joy of nature. Yet, both are also in their 80s.