In a new Vox video, Bill Gates shares which frightening scenario keeps him awake at night.
"This is the greatest risk of a huge tragedy. This is the most likely thing by far to kill over 10 million excess people in a year. We don't need to invest nearly what we do in military preparedness. This is something where less than a billion a year [can make a difference]… and we may not get more warnings like this one to say okay, it's a pretty modest investment to avoid something that really in terms of the human condition would be a gigantic setback."
Watch, AFTER THE JUMP…
