As the tour guide for this Sunday’s Sagan Planet Walk approached the nearly 500 tourists, scientists, students and Ithaca residents gathered on the Commons, women shrieked and flashbulbs snapped.

A bow-tied Bill Nye the Science Guy joined other smarty-pants experts and climate scientists on the stage at the Boulder Theater this week for a lecture on “Climate Change on Earth and Other Planets.” ...

This Election day, Bill Nye has one message for young people: “Vote with the climate in mind.” Since September, America’s beloved science guy has been injecting social media platforms with snappy, ...