Today marks the 35th installment in a series of articles by HumanProgress.org titled Heroes of Progress. This bi-weekly column provides a short introduction to heroes who have made an extraordinary contribution to the well-being of humanity. You can find the 34th part of this series here.

This week, our hero is Enrico Fermi, the Italian-American physicist who created the world’s first nuclear reactor. Although controversial among many, nuclear power remains the main source of zero-carbon energy that, scientists from NASA calculate, saved millions of people from air pollution-related deaths.