This is the 2010 TED Talk that launched a thousand YouTube uploads and as many sardonic memes. Probably more, actually. It’s one of many public speaking forays Bill Gates has made to announce his plan to save the world from runaway carbon dioxide by lowering population growth to zero with vaccines.
Yes, you heard him right: “The world today has 6.8 billion people. That’s headed up to about 9 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.”
He explains how this works 8 years later, here.