I keep looking at that video, my first impulse is to say that he means that the INCREASE in CO2 has to be brought down to zero and he is just a very poor communicator but I am not certain that he even understands what he is saying. He is totally out of his depth, lecturing an audience on a subject about which he understands literally nothing.
When he gets to the bit about vaccinations and health care slowing the population increase I am flabbergasted. It seems that either he is saying that vaccinations and health care can sterilize people and or kill people (how else would they slow population growth) or he is just too damned stupid to know what he is saying.
“he is just too damned stupid to know what he is saying.”
Gates is a perfect example of “The Peter Principle”.