Of all the life-changing events on Earth during the last 200 years, what happened here in the 20th Century co?

Its an opinion question, but answer why to the event you pick.Of all the life-changing events on Earth during the last 200 years, what happened here in the 20th Century co?Tons. More has happened in the past hundred years maybe even less than has happened in all of time. Look at technology and inventions alone and how they have helped us. Then look at the leaps and bounds we've made in medicine in such just to name a few. It's impossible to name everything. Hell, I think in the past ten years more has changed than anything in history but that might be stretching it.