The world is a dangerous place. Professor Richard Olson, an expert in disaster preparedness, only needed a few seconds to prove that to the audience listening to his TEDxFIU talk. His maps told the whole story: at any given time, tsunamis, earthquakes, volcanoes and hurricanes threaten some of the Earth’s largest cities; and our planet’s population is only getting larger.

“Natural disasters. It trips off the tongue,” he said. “But natural disasters? Not so much. Natural events? Yes. Nature provides those. But the disasters, what we put in harm’s way, well, that’s on us.”

Population Growth Areas. Credit: PBS, NOVA

And as our population grows, so do the risks of catastrophic loss of life. Here’s another problem: For many countries around the globe, if their major city is struck by disaster, the entire nation is paralyzed.

So Olson has spent his entire career convincing world leaders that building massive cities ultimately contributes to high death tolls. He calls it the 21st century imperative: create “second” cities that spread populations out. “We need to create national tiers of second cities. They need to be safer, they need to be vital. In many countires, if you lose the lead city, the country goes down. Second cities would spread the risk.