Bill gates talks about his top 3 wishes from Co2 Ted Talk

"If you gave me only one wish for the next 50 years — I could pick who's president, I could pick a vaccine, which is something I love(?!), or I could pick that this thing that's half the cost with no CO2 gets invented — this is the wish I would pick. This is the one with the greatest impact."

This was after he said:

"First, we've got population. The world today has 6.8 billion people. That's headed up to about nine billion. Now, if we do a really great job on new vaccines, health care, reproductive health services, we could lower that by, perhaps, 10 or 15 percent!"