Norman Borlaug saved possibly over a billion lives by using science to help defeat these variables. Borlaug was an Iowan farm boy who received his education from life and the University of Minnesota. In the 1940s Borlaug began to develop species of wheat that could resist diseases and flourish in a variety of environments. His crops spread from Mexico to Pakistan then to Africa. While scientific doomsayers were saying that humanity was about to collapse due to overpopulation, Borlaug showed how science can readjust the equations. Today food crises are limited to ones that involve poor human practices (Ethiopian overgrazing) to authoritarian mismanagement (North Korea, Zimbabwe).
Reason has a great obituary for Borlaug. It is much better than one I could ever do. While some may harp on Borlaug for his Nobel Peace Prize and other awards, I think he should best be remembered for saving perhaps a billion lives. We will never know exactly how many lives would have been lost if it was not for Borlaug's Green Revolution... thank God.