In the 2018 Annual Letter event of the Gates Foundation, American entrepreneur and Microsoft founder Bill Gates chose a tough question to answer. Does saving lives contribute to over-population?

Gates took up the question asked by many. As people get healthier and live longer, will feeding everybody without damaging the environment be possible?

Gates showed viewers a chart, giving them a glimpse into the world’s population growth over several hundred years. He acknowledged the massive growth in the number of people: “At first glance, this is a bit scary.”

But his discovery is fascinating. When the quality of health increases, more people choose to have fewer children.

“This effect is very, very dramatic,” Gates explained. “We find that in every country in the world, this is repeated. The population rate goes down as we improve health.” And that might answer the question.