Nepal, May 11 -- t was a packed hall in the summer of 2019 at the 20th anniversary of the Student Conference on Conservation Science in Cambridge. An empty chair on the stage waited for one man.

Hundreds of students and researchers excitedly anticipated the arrival of Sir David Attenborough. The British nature broadcaster and writer marked his 100th birthday this week, but back then at age 93 he was as sharp and witty as ever.

I was one of 25 researchers selected to ask him a question that day, and waited nervously for my turn. My question concerned the dilemma we face in Nepal: "How can developing nations prioritise conservation while simultaneously tackling poverty and daily livelihood crises?"

Sir David paused for a while, smiled,...